From 3ec7818eaa12f124313637331ad7e5e0a4420faa Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Mon, 26 May 2014 09:41:12 +0300
Subject: [PATCH 01/22] Add getLastQuery() in readme

---
 readme.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/readme.md b/readme.md
index 96558337..0de4ccd1 100644
--- a/readme.md
+++ b/readme.md
@@ -227,3 +227,10 @@ Obtain an initialized instance of the class from another class
 ```php
     $db = MysqliDb::getInstance();
 ```
+
+Get last executed SQL query.
+Please note that function returns SQL query only for debugging purposes as its execution most likely will fail due missing quotes around char variables.
+```php
+    $db->get('users');
+    echo "Last executed query was ". $db->getLastQuery();
+```

From c7709294ee2df76629673f0bc1dc17f5f8c72c03 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 16:39:17 +0300
Subject: [PATCH 02/22] Fix table drop in tests

---
 tests.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests.php b/tests.php
index 2eb65255..df51f3dc 100644
--- a/tests.php
+++ b/tests.php
@@ -94,7 +94,7 @@ function createTable ($name, $data) {
 }
 
 foreach ($tables as $name => $fields) {
-    $db->rawQuery("DROP TABLE $name");
+    $db->rawQuery("DROP TABLE ".$prefix.$name);
     createTable ($prefix.$name, $fields);
 }
 

From 9503e130af47e4fdd80a8d296496a5ea3470583b Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 17:08:29 +0300
Subject: [PATCH 03/22] Add one more test

---
 tests.php | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tests.php b/tests.php
index df51f3dc..275f354c 100644
--- a/tests.php
+++ b/tests.php
@@ -217,6 +217,13 @@ function createTable ($name, $data) {
     exit;
 }
 
+$db->where("id = 1 or id = 2");
+$res = $db->get ("users");
+if ($db->count != 2) {
+    echo "Invalid users count on select with multiple params";
+    exit;
+}
+
 $db->delete("users");
 $db->get("users");
 if ($db->count != 0) {

From 3214680b72575c2431b2a66c56d0bbb5c7d388a1 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 17:08:41 +0300
Subject: [PATCH 04/22] Initial subqueries support API

---
 MysqliDb.php | 103 ++++++++++++++++++++++++++++++++++++++++++++-------
 readme.md    |  10 +++++
 2 files changed, 100 insertions(+), 13 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 32d794bd..ee0a43c5 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -93,6 +93,12 @@ class MysqliDb
     protected $db;
     protected $port;
 
+    /**
+     * Is Subquery object
+     *
+     */
+    protected $isSubQuery = false;
+
     /**
      * @param string $host
      * @param string $username
@@ -100,7 +106,7 @@ class MysqliDb
      * @param string $db
      * @param int $port
      */
-    public function __construct($host, $username, $password, $db, $port = NULL)
+    public function __construct($host = NULL, $username = NULL, $password = NULL, $db = NULL, $port = NULL)
     {
         $this->host = $host;
         $this->username = $username;
@@ -110,9 +116,14 @@ public function __construct($host, $username, $password, $db, $port = NULL)
             $this->port = ini_get ('mysqli.default_port');
         else
             $this->port = $port;
-        
-        $this->connect();
         $this->setPrefix();
+
+        if ($host == null && $username == null && $db == null) {
+            $this->isSubQuery = true;
+            return;
+        }
+        // for subqueries we do not need database connection and redefine root instance
+        $this->connect();
         self::$_instance = $this;
     }
 
@@ -122,6 +133,9 @@ public function __construct($host, $username, $password, $db, $port = NULL)
      */
     public function connect()
     {
+        if ($this->isSubQuery)
+            return;
+
         $this->_mysqli = new mysqli ($this->host, $this->username, $this->password, $this->db, $this->port)
             or die('There was a problem connecting to the database');
 
@@ -165,6 +179,7 @@ protected function reset()
     public function setPrefix($prefix = '')
     {
         $this->_prefix = $prefix;
+        return $this;
     }
 
     /**
@@ -233,6 +248,10 @@ public function get($tableName, $numRows = null, $columns = '*')
         $column = is_array($columns) ? implode(', ', $columns) : $columns; 
         $this->_query = "SELECT $column FROM $this->_prefix$tableName";
         $stmt = $this->_buildQuery($numRows);
+
+        if ($this->isSubQuery)
+            return $this;
+
         $stmt->execute();
         $this->_stmtError = $stmt->error;
         $this->reset();
@@ -250,6 +269,10 @@ public function get($tableName, $numRows = null, $columns = '*')
     public function getOne($tableName, $columns = '*') 
     {
         $res = $this->get ($tableName, 1, $columns);
+
+        if (is_object($res))
+            return $res;
+
         if (isset($res[0]))
             return $res[0];
 
@@ -265,6 +288,9 @@ public function getOne($tableName, $columns = '*')
      */
     public function insert($tableName, $insertData)
     {
+        if ($this->isSubQuery)
+            return;
+
         $this->_query = "INSERT into $this->_prefix$tableName";
         $stmt = $this->_buildQuery(null, $insertData);
         $stmt->execute();
@@ -284,6 +310,9 @@ public function insert($tableName, $insertData)
      */
     public function update($tableName, $tableData)
     {
+        if ($this->isSubQuery)
+            return;
+
         $this->_query = "UPDATE $this->_prefix$tableName SET ";
 
         $stmt = $this->_buildQuery(null, $tableData);
@@ -304,6 +333,9 @@ public function update($tableName, $tableData)
      */
     public function delete($tableName, $numRows = null)
     {
+        if ($this->isSubQuery)
+            return;
+
         $this->_query = "DELETE FROM $this->_prefix$tableName";
 
         $stmt = $this->_buildQuery($numRows);
@@ -488,6 +520,21 @@ protected function _bindParam($value)
         array_push ($this->_bindParams, $value);
     }
 
+    protected function _buildPair ($operator, $value) {
+        if (!is_object($value)) {
+            $this->_bindParam ($value);
+            $comparison = ' ' . $operator. ' ? ';
+            return $comparison;
+        }
+
+        $subQuery = $value->getSubQuery();
+        $comparison = " " . $operator . " (" . $subQuery['query'] . ")";
+        foreach ($subQuery['params'] as $v)
+            $this->_bindParam ($v);
+
+        return $comparison;
+    }
+
     /**
      * Abstraction method that will compile the WHERE statement,
      * any passed update data, and the desired rows.
@@ -582,9 +629,13 @@ protected function _buildQuery($numRows = null, $tableData = null)
                         case 'not in':
                         case 'in':
                             $comparison = ' ' . $key . ' (';
-                            foreach($val as $v){
-                                $comparison .= ' ?,';
-                                $this->_bindParam ($v);
+                            if (is_object ($val)) {
+                                $comparison .= $this->_buildPair ("", $val);
+                            } else {
+                                foreach ($val as $v) {
+                                    $comparison .= ' ?,';
+                                    $this->_bindParam ($v);
+                                }
                             }
                             $comparison = rtrim($comparison, ',').' ) ';
                             break;
@@ -596,14 +647,12 @@ protected function _buildQuery($numRows = null, $tableData = null)
                             break;
                         default:
                             // We are using a comparison operator with only one parameter after it
-                            $comparison = ' '.$key.' ? ';
-                            $this->_bindParam ($val);
+                            $comparison = $this->_buildPair ($key, $val);
                     }
                 } else if ($value[1] === null) {
                     $comparison = '';
                 } else {
-                    $comparison = ' = ? ';
-                    $this->_bindParam ($value[1]);
+                    $comparison = $this->_buildPair ("=", $value[1]);
                 }
                 $this->_query .= $column.$comparison;
             }
@@ -637,6 +686,11 @@ protected function _buildQuery($numRows = null, $tableData = null)
                 $this->_query .= ' LIMIT ' . (int)$numRows;
         }
 
+        $this->_lastQuery = $this->replacePlaceHolders($this->_query, $this->_bindParams);
+
+        if ($this->isSubQuery)
+            return;
+
         // Prepare query
         $stmt = $this->_prepareQuery();
 
@@ -644,7 +698,6 @@ protected function _buildQuery($numRows = null, $tableData = null)
         if (count ($this->_bindParams) > 1)
             call_user_func_array(array($stmt, 'bind_param'), $this->refValues($this->_bindParams));
 
-        $this->_lastQuery = $this->replacePlaceHolders($this->_query, $this->_bindParams);
         return $stmt;
     }
 
@@ -708,7 +761,8 @@ protected function _prepareQuery()
      */
     public function __destruct()
     {
-        $this->_mysqli->close();
+        if (!$this->isSubQuery)
+            $this->_mysqli->close();
     }
 
     /**
@@ -741,7 +795,10 @@ protected function replacePlaceHolders ($str, $vals) {
         $newStr = "";
 
         while ($pos = strpos ($str, "?")) {
-            $newStr .= substr ($str, 0, $pos) . $vals[$i++];
+            $val = $vals[$i++];
+            if (is_object ($val))
+                $val = '[object]';
+            $newStr .= substr ($str, 0, $pos) . $val;
             $str = substr ($str, $pos + 1);
         }
         return $newStr;
@@ -765,6 +822,18 @@ public function getLastError () {
         return $this->_stmtError . " " . $this->_mysqli->error;
     }
 
+    public function getSubQuery () {
+        if (!$this->isSubQuery)
+            return null;
+
+        array_shift ($this->_bindParams);
+        $val = Array ('query' => $this->_query,
+                      'params' => $this->_bindParams
+                );
+        $this->reset();
+        return $val;
+    }
+
     /* Helper functions */
     /**
      * Method returns generated interval function as a string
@@ -841,4 +910,12 @@ public function func ($expr, $bindParams = null) {
         return Array ("[F]" => Array($expr, $bindParams));
     }
 
+    /**
+     * Method creates new mysqlidb object for a subquery generation
+     */
+    public static function subQuery()
+    {
+        return new MysqliDb();
+    }
+
 } // END class
diff --git a/readme.md b/readme.md
index 0de4ccd1..5b8aeb5f 100644
--- a/readme.md
+++ b/readme.md
@@ -216,6 +216,16 @@ $products = $db->get ("products p", null, "u.name, p.productName");
 print_r ($products);
 ```
 
+### Subqueries
+```php
+$db->where("id", Array("in" => $db->subQuery()
+                    ->where("qty", Array (">" => 2));
+                    ->get("products",null,"userId")
+    ));
+
+$res = $db->get ("users");
+// Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)
+```
 ### Helper commands
 Reconnect in case mysql connection died
 ```php

From 99909967cb1d952c9633e83d489c5c645d85e5df Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 18:41:07 +0300
Subject: [PATCH 05/22] Minor fixes

---
 MysqliDb.php | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index ee0a43c5..d1ba6ff8 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -270,7 +270,7 @@ public function getOne($tableName, $columns = '*')
     {
         $res = $this->get ($tableName, 1, $columns);
 
-        if (is_object($res))
+        if ($this->isSubQuery)
             return $res;
 
         if (isset($res[0]))
@@ -795,10 +795,7 @@ protected function replacePlaceHolders ($str, $vals) {
         $newStr = "";
 
         while ($pos = strpos ($str, "?")) {
-            $val = $vals[$i++];
-            if (is_object ($val))
-                $val = '[object]';
-            $newStr .= substr ($str, 0, $pos) . $val;
+            $newStr .= substr ($str, 0, $pos) . $vals[$i++];
             $str = substr ($str, $pos + 1);
         }
         return $newStr;

From c1d40ca6302766b90be9168e675919218ceb2ebd Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 18:49:23 +0300
Subject: [PATCH 06/22] Prefix should be static to be shareble with subqueries

---
 MysqliDb.php | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index d1ba6ff8..44c10b92 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -24,7 +24,7 @@ class MysqliDb
      * 
      * @var string
      */
-    protected $_prefix;
+    protected static $_prefix;
     /**
      * MySQLi instance
      *
@@ -116,14 +116,15 @@ public function __construct($host = NULL, $username = NULL, $password = NULL, $d
             $this->port = ini_get ('mysqli.default_port');
         else
             $this->port = $port;
-        $this->setPrefix();
 
         if ($host == null && $username == null && $db == null) {
             $this->isSubQuery = true;
             return;
         }
+
         // for subqueries we do not need database connection and redefine root instance
         $this->connect();
+        $this->setPrefix();
         self::$_instance = $this;
     }
 
@@ -178,7 +179,7 @@ protected function reset()
      */
     public function setPrefix($prefix = '')
     {
-        $this->_prefix = $prefix;
+        self::$_prefix = $prefix;
         return $this;
     }
 
@@ -246,7 +247,7 @@ public function get($tableName, $numRows = null, $columns = '*')
             $columns = '*';
 
         $column = is_array($columns) ? implode(', ', $columns) : $columns; 
-        $this->_query = "SELECT $column FROM $this->_prefix$tableName";
+        $this->_query = "SELECT $column FROM " .self::$_prefix . $tableName;
         $stmt = $this->_buildQuery($numRows);
 
         if ($this->isSubQuery)
@@ -291,7 +292,7 @@ public function insert($tableName, $insertData)
         if ($this->isSubQuery)
             return;
 
-        $this->_query = "INSERT into $this->_prefix$tableName";
+        $this->_query = "INSERT into " .self::$_prefix . $tableName;
         $stmt = $this->_buildQuery(null, $insertData);
         $stmt->execute();
         $this->_stmtError = $stmt->error;
@@ -313,7 +314,7 @@ public function update($tableName, $tableData)
         if ($this->isSubQuery)
             return;
 
-        $this->_query = "UPDATE $this->_prefix$tableName SET ";
+        $this->_query = "UPDATE " . self::$_prefix . $tableName ." SET ";
 
         $stmt = $this->_buildQuery(null, $tableData);
         $stmt->execute();
@@ -336,7 +337,7 @@ public function delete($tableName, $numRows = null)
         if ($this->isSubQuery)
             return;
 
-        $this->_query = "DELETE FROM $this->_prefix$tableName";
+        $this->_query = "DELETE FROM " . self::$_prefix . $tableName;
 
         $stmt = $this->_buildQuery($numRows);
         $stmt->execute();
@@ -397,7 +398,7 @@ public function join($joinTable, $joinCondition, $joinType = '')
         if ($joinType && !in_array ($joinType, $allowedTypes))
             die ('Wrong JOIN type: '.$joinType);
 
-        $this->_join[$joinType . " JOIN " . $this->_prefix.$joinTable] = $joinCondition;
+        $this->_join[$joinType . " JOIN " . self::$_prefix . $joinTable] = $joinCondition;
 
         return $this;
     }

From ab6caff51b6705922f5212521c358097005505d6 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 19:27:26 +0300
Subject: [PATCH 07/22] Added nicer where API to define operators

---
 MysqliDb.php | 10 ++++++++--
 readme.md    | 20 ++++++++++----------
 tests.php    |  8 ++++----
 3 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 44c10b92..5304df66 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -357,8 +357,11 @@ public function delete($tableName, $numRows = null)
      *
      * @return MysqliDb
      */
-    public function where($whereProp, $whereValue = null)
+    public function where($whereProp, $whereValue = null, $operator = null)
     {
+        if ($operator)
+            $whereValue = Array ($operator => $whereValue);
+
         $this->_where[$whereProp] = Array ("AND", $whereValue);
         return $this;
     }
@@ -373,8 +376,11 @@ public function where($whereProp, $whereValue = null)
      *
      * @return MysqliDb
      */
-    public function orWhere($whereProp, $whereValue = null)
+    public function orWhere($whereProp, $whereValue = null, $operator = null)
     {
+        if ($operator)
+            $whereValue = Array ($operator => $whereValue);
+
         $this->_where[$whereProp] = Array ("OR", $whereValue);
         return $this;
     }
diff --git a/readme.md b/readme.md
index 5b8aeb5f..c5bd5364 100644
--- a/readme.md
+++ b/readme.md
@@ -133,23 +133,23 @@ $results = $db->get('users');
 ```
 
 ```php
-$db->where('id', Array('>=' => 50));
+$db->where('id', 50, ">=");
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id >= 50;
 ```
 
 BETWEEN:
 ```php
-$db->where('id', Array('between' => Array(4, 20) ) );
-//$db->where('id', Array('not between' => Array(4, 20) ) );
+$db->where('id', Array(4, 20), 'between');
+//$db->where('id', Array(4, 20), 'not between');
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id BETWEEN 4 AND 20
 ```
 
 IN:
 ```php
-$db->where('id', Array( 'in' => Array(1, 5, 27, -1, 'd') ) );
-//$db->where('id', Array( 'not in' => Array(1, 5, 27, -1, 'd') ) );
+$db->where('id', Array(1, 5, 27, -1, 'd'), 'IN');
+//$db->where('id', Array(1, 5, 27, -1, 'd'), 'NOT IN');
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');
 ```
@@ -164,7 +164,7 @@ $results = $db->get('users');
 
 NULL comparison:
 ```php
-$db->where ("lastName", Array("<=>" => NULL));
+$db->where ("lastName", NULL, '<=>');
 $results = $db->get("users");
 // Gives: SELECT * FROM users where lastName <=> NULL
 ```
@@ -218,10 +218,10 @@ print_r ($products);
 
 ### Subqueries
 ```php
-$db->where("id", Array("in" => $db->subQuery()
-                    ->where("qty", Array (">" => 2));
-                    ->get("products",null,"userId")
-    ));
+$db->where("id", $db->subQuery()
+                    ->where("qty", 2, ">")
+                    ->get("products",null,"userId"),
+            'in');
 
 $res = $db->get ("users");
 // Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)
diff --git a/tests.php b/tests.php
index 275f354c..ce2adbf1 100644
--- a/tests.php
+++ b/tests.php
@@ -138,7 +138,7 @@ function createTable ($name, $data) {
 //$users = $db->get("users");
 //print_r ($users);
 
-$db->where("firstname", Array("LIKE" => '%John%'));
+$db->where("firstname", '%John%', 'LIKE');
 $users = $db->get("users");
 if ($db->count != 1) {
     echo "Invalid insert count in LIKE: ".$db->count;
@@ -172,14 +172,14 @@ function createTable ($name, $data) {
     exit;
 }
 
-$db->where ("id", Array('in' => Array('1','2','3')));
+$db->where ("id", Array('1','2','3'), 'IN');
 $db->get("users");
 if ($db->count != 3) {
     echo "Invalid users count on where() with in ";
     exit;
 }
 
-$db->where ("id", Array('between' => Array('2','3')));
+$db->where ("id", Array('2','3'), 'between');
 $db->get("users");
 if ($db->count != 2) {
     echo "Invalid users count on where() with between";
@@ -194,7 +194,7 @@ function createTable ($name, $data) {
     exit;
 }
 
-$db->where ("lastName", Array("<=>" => NULL));
+$db->where ("lastName", NULL, '<=>');
 $r = $db->get("users");
 if ($db->count != 1) {
     echo "Invalid users count on null where()";

From 8f513b0a56bebc60610570f231af6306c9b9c454 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 20:43:48 +0300
Subject: [PATCH 08/22] Revert "Minor fixes"

This reverts commit 99909967cb1d952c9633e83d489c5c645d85e5df.
---
 MysqliDb.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 5304df66..c06073ed 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -271,7 +271,7 @@ public function getOne($tableName, $columns = '*')
     {
         $res = $this->get ($tableName, 1, $columns);
 
-        if ($this->isSubQuery)
+        if (is_object($res))
             return $res;
 
         if (isset($res[0]))
@@ -802,7 +802,10 @@ protected function replacePlaceHolders ($str, $vals) {
         $newStr = "";
 
         while ($pos = strpos ($str, "?")) {
-            $newStr .= substr ($str, 0, $pos) . $vals[$i++];
+            $val = $vals[$i++];
+            if (is_object ($val))
+                $val = '[object]';
+            $newStr .= substr ($str, 0, $pos) . $val;
             $str = substr ($str, $pos + 1);
         }
         return $newStr;

From 7a71c491cc1dfaa3d298ba88bd2eb59772a206aa Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 20:51:15 +0300
Subject: [PATCH 09/22] Subquery support in UPDATE/INSERT

---
 MysqliDb.php | 4 +++-
 readme.md    | 7 ++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index c06073ed..b798a76c 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -579,7 +579,9 @@ protected function _buildQuery($numRows = null, $tableData = null)
                 if ($isUpdate !== false)
                     $this->_query .= "`" . $column . "` = ";
 
-                if (!is_array ($value)) {
+                if (is_object ($value)) {
+                    $this->_query .= $this->_buildPair ("", $value) . ", ";
+                } else if (!is_array ($value)) {
                     $this->_bindParam ($value);
                     $this->_query .= '?, ';
                 } else {
diff --git a/readme.md b/readme.md
index c5bd5364..efd9f142 100644
--- a/readme.md
+++ b/readme.md
@@ -218,11 +218,8 @@ print_r ($products);
 
 ### Subqueries
 ```php
-$db->where("id", $db->subQuery()
-                    ->where("qty", 2, ">")
-                    ->get("products",null,"userId"),
-            'in');
-
+$ids = $db->subQuery()->where("qty", 2, ">")->get("products", null, "userId");
+$db->where("id", $ids, 'in');
 $res = $db->get ("users");
 // Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)
 ```

From b6d5e9bfa45da32ba346ead4747b20495a3948c1 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 17:08:41 +0300
Subject: [PATCH 10/22] Subqueries support API

---
 MysqliDb.php | 126 +++++++++++++++++++++++++++++++++++++++++++--------
 readme.md    |   7 +++
 2 files changed, 113 insertions(+), 20 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 32d794bd..4f99f70b 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -24,7 +24,7 @@ class MysqliDb
      * 
      * @var string
      */
-    protected $_prefix;
+    protected static $_prefix;
     /**
      * MySQLi instance
      *
@@ -93,6 +93,12 @@ class MysqliDb
     protected $db;
     protected $port;
 
+    /**
+     * Is Subquery object
+     *
+     */
+    protected $isSubQuery = false;
+
     /**
      * @param string $host
      * @param string $username
@@ -100,7 +106,7 @@ class MysqliDb
      * @param string $db
      * @param int $port
      */
-    public function __construct($host, $username, $password, $db, $port = NULL)
+    public function __construct($host = NULL, $username = NULL, $password = NULL, $db = NULL, $port = NULL)
     {
         $this->host = $host;
         $this->username = $username;
@@ -110,7 +116,13 @@ public function __construct($host, $username, $password, $db, $port = NULL)
             $this->port = ini_get ('mysqli.default_port');
         else
             $this->port = $port;
-        
+
+        if ($host == null && $username == null && $db == null) {
+            $this->isSubQuery = true;
+            return;
+        }
+
+        // for subqueries we do not need database connection and redefine root instance
         $this->connect();
         $this->setPrefix();
         self::$_instance = $this;
@@ -122,6 +134,9 @@ public function __construct($host, $username, $password, $db, $port = NULL)
      */
     public function connect()
     {
+        if ($this->isSubQuery)
+            return;
+
         $this->_mysqli = new mysqli ($this->host, $this->username, $this->password, $this->db, $this->port)
             or die('There was a problem connecting to the database');
 
@@ -164,7 +179,8 @@ protected function reset()
      */
     public function setPrefix($prefix = '')
     {
-        $this->_prefix = $prefix;
+        self::$_prefix = $prefix;
+        return $this;
     }
 
     /**
@@ -231,8 +247,12 @@ public function get($tableName, $numRows = null, $columns = '*')
             $columns = '*';
 
         $column = is_array($columns) ? implode(', ', $columns) : $columns; 
-        $this->_query = "SELECT $column FROM $this->_prefix$tableName";
+        $this->_query = "SELECT $column FROM " .self::$_prefix . $tableName;
         $stmt = $this->_buildQuery($numRows);
+
+        if ($this->isSubQuery)
+            return $this;
+
         $stmt->execute();
         $this->_stmtError = $stmt->error;
         $this->reset();
@@ -250,6 +270,10 @@ public function get($tableName, $numRows = null, $columns = '*')
     public function getOne($tableName, $columns = '*') 
     {
         $res = $this->get ($tableName, 1, $columns);
+
+        if (is_object($res))
+            return $res;
+
         if (isset($res[0]))
             return $res[0];
 
@@ -265,7 +289,10 @@ public function getOne($tableName, $columns = '*')
      */
     public function insert($tableName, $insertData)
     {
-        $this->_query = "INSERT into $this->_prefix$tableName";
+        if ($this->isSubQuery)
+            return;
+
+        $this->_query = "INSERT into " .self::$_prefix . $tableName;
         $stmt = $this->_buildQuery(null, $insertData);
         $stmt->execute();
         $this->_stmtError = $stmt->error;
@@ -284,7 +311,10 @@ public function insert($tableName, $insertData)
      */
     public function update($tableName, $tableData)
     {
-        $this->_query = "UPDATE $this->_prefix$tableName SET ";
+        if ($this->isSubQuery)
+            return;
+
+        $this->_query = "UPDATE " . self::$_prefix . $tableName ." SET ";
 
         $stmt = $this->_buildQuery(null, $tableData);
         $stmt->execute();
@@ -304,7 +334,10 @@ public function update($tableName, $tableData)
      */
     public function delete($tableName, $numRows = null)
     {
-        $this->_query = "DELETE FROM $this->_prefix$tableName";
+        if ($this->isSubQuery)
+            return;
+
+        $this->_query = "DELETE FROM " . self::$_prefix . $tableName;
 
         $stmt = $this->_buildQuery($numRows);
         $stmt->execute();
@@ -365,7 +398,7 @@ public function join($joinTable, $joinCondition, $joinType = '')
         if ($joinType && !in_array ($joinType, $allowedTypes))
             die ('Wrong JOIN type: '.$joinType);
 
-        $this->_join[$joinType . " JOIN " . $this->_prefix.$joinTable] = $joinCondition;
+        $this->_join[$joinType . " JOIN " . self::$_prefix . $joinTable] = $joinCondition;
 
         return $this;
     }
@@ -488,6 +521,21 @@ protected function _bindParam($value)
         array_push ($this->_bindParams, $value);
     }
 
+    protected function _buildPair ($operator, $value) {
+        if (!is_object($value)) {
+            $this->_bindParam ($value);
+            $comparison = ' ' . $operator. ' ? ';
+            return $comparison;
+        }
+
+        $subQuery = $value->getSubQuery();
+        $comparison = " " . $operator . " (" . $subQuery['query'] . ")";
+        foreach ($subQuery['params'] as $v)
+            $this->_bindParam ($v);
+
+        return $comparison;
+    }
+
     /**
      * Abstraction method that will compile the WHERE statement,
      * any passed update data, and the desired rows.
@@ -525,7 +573,9 @@ protected function _buildQuery($numRows = null, $tableData = null)
                 if ($isUpdate !== false)
                     $this->_query .= "`" . $column . "` = ";
 
-                if (!is_array ($value)) {
+                if (is_object ($value)) {
+                    $this->_query .= $this->_buildPair ("", $value) . ", ";
+                } else if (!is_array ($value)) {
                     $this->_bindParam ($value);
                     $this->_query .= '?, ';
                 } else {
@@ -582,9 +632,13 @@ protected function _buildQuery($numRows = null, $tableData = null)
                         case 'not in':
                         case 'in':
                             $comparison = ' ' . $key . ' (';
-                            foreach($val as $v){
-                                $comparison .= ' ?,';
-                                $this->_bindParam ($v);
+                            if (is_object ($val)) {
+                                $comparison .= $this->_buildPair ("", $val);
+                            } else {
+                                foreach ($val as $v) {
+                                    $comparison .= ' ?,';
+                                    $this->_bindParam ($v);
+                                }
                             }
                             $comparison = rtrim($comparison, ',').' ) ';
                             break;
@@ -596,14 +650,12 @@ protected function _buildQuery($numRows = null, $tableData = null)
                             break;
                         default:
                             // We are using a comparison operator with only one parameter after it
-                            $comparison = ' '.$key.' ? ';
-                            $this->_bindParam ($val);
+                            $comparison = $this->_buildPair ($key, $val);
                     }
                 } else if ($value[1] === null) {
                     $comparison = '';
                 } else {
-                    $comparison = ' = ? ';
-                    $this->_bindParam ($value[1]);
+                    $comparison = $this->_buildPair ("=", $value[1]);
                 }
                 $this->_query .= $column.$comparison;
             }
@@ -637,6 +689,11 @@ protected function _buildQuery($numRows = null, $tableData = null)
                 $this->_query .= ' LIMIT ' . (int)$numRows;
         }
 
+        $this->_lastQuery = $this->replacePlaceHolders($this->_query, $this->_bindParams);
+
+        if ($this->isSubQuery)
+            return;
+
         // Prepare query
         $stmt = $this->_prepareQuery();
 
@@ -644,7 +701,6 @@ protected function _buildQuery($numRows = null, $tableData = null)
         if (count ($this->_bindParams) > 1)
             call_user_func_array(array($stmt, 'bind_param'), $this->refValues($this->_bindParams));
 
-        $this->_lastQuery = $this->replacePlaceHolders($this->_query, $this->_bindParams);
         return $stmt;
     }
 
@@ -708,7 +764,8 @@ protected function _prepareQuery()
      */
     public function __destruct()
     {
-        $this->_mysqli->close();
+        if (!$this->isSubQuery)
+            $this->_mysqli->close();
     }
 
     /**
@@ -741,7 +798,10 @@ protected function replacePlaceHolders ($str, $vals) {
         $newStr = "";
 
         while ($pos = strpos ($str, "?")) {
-            $newStr .= substr ($str, 0, $pos) . $vals[$i++];
+            $val = $vals[$i++];
+            if (is_object ($val))
+                $val = '[object]';
+            $newStr .= substr ($str, 0, $pos) . $val;
             $str = substr ($str, $pos + 1);
         }
         return $newStr;
@@ -765,6 +825,24 @@ public function getLastError () {
         return $this->_stmtError . " " . $this->_mysqli->error;
     }
 
+    /**
+     * Mostly internal method to get query and its params out of subquery object
+     * after get() and getAll()
+     * 
+     * @return array
+     */
+    public function getSubQuery () {
+        if (!$this->isSubQuery)
+            return null;
+
+        array_shift ($this->_bindParams);
+        $val = Array ('query' => $this->_query,
+                      'params' => $this->_bindParams
+                );
+        $this->reset();
+        return $val;
+    }
+
     /* Helper functions */
     /**
      * Method returns generated interval function as a string
@@ -841,4 +919,12 @@ public function func ($expr, $bindParams = null) {
         return Array ("[F]" => Array($expr, $bindParams));
     }
 
+    /**
+     * Method creates new mysqlidb object for a subquery generation
+     */
+    public static function subQuery()
+    {
+        return new MysqliDb();
+    }
+
 } // END class
diff --git a/readme.md b/readme.md
index 0de4ccd1..d8ce4ba3 100644
--- a/readme.md
+++ b/readme.md
@@ -216,6 +216,13 @@ $products = $db->get ("products p", null, "u.name, p.productName");
 print_r ($products);
 ```
 
+### Subqueries
+```php
+$ids = $db->subQuery()->where("qty", 2, ">")->get("products", null, "userId");
+$db->where("id", $ids, 'in');
+$res = $db->get ("users");
+// Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)
+```
 ### Helper commands
 Reconnect in case mysql connection died
 ```php

From 6261af4f9ebb5f577d28aa5e9d20b31e6862925f Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Wed, 28 May 2014 19:27:26 +0300
Subject: [PATCH 11/22] Added nicer where API to define operators

---
 MysqliDb.php | 10 ++++++++--
 readme.md    | 12 ++++++------
 tests.php    |  8 ++++----
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 4f99f70b..0b5a2e14 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -357,8 +357,11 @@ public function delete($tableName, $numRows = null)
      *
      * @return MysqliDb
      */
-    public function where($whereProp, $whereValue = null)
+    public function where($whereProp, $whereValue = null, $operator = null)
     {
+        if ($operator)
+            $whereValue = Array ($operator => $whereValue);
+
         $this->_where[$whereProp] = Array ("AND", $whereValue);
         return $this;
     }
@@ -373,8 +376,11 @@ public function where($whereProp, $whereValue = null)
      *
      * @return MysqliDb
      */
-    public function orWhere($whereProp, $whereValue = null)
+    public function orWhere($whereProp, $whereValue = null, $operator = null)
     {
+        if ($operator)
+            $whereValue = Array ($operator => $whereValue);
+
         $this->_where[$whereProp] = Array ("OR", $whereValue);
         return $this;
     }
diff --git a/readme.md b/readme.md
index d8ce4ba3..efd9f142 100644
--- a/readme.md
+++ b/readme.md
@@ -133,23 +133,23 @@ $results = $db->get('users');
 ```
 
 ```php
-$db->where('id', Array('>=' => 50));
+$db->where('id', 50, ">=");
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id >= 50;
 ```
 
 BETWEEN:
 ```php
-$db->where('id', Array('between' => Array(4, 20) ) );
-//$db->where('id', Array('not between' => Array(4, 20) ) );
+$db->where('id', Array(4, 20), 'between');
+//$db->where('id', Array(4, 20), 'not between');
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id BETWEEN 4 AND 20
 ```
 
 IN:
 ```php
-$db->where('id', Array( 'in' => Array(1, 5, 27, -1, 'd') ) );
-//$db->where('id', Array( 'not in' => Array(1, 5, 27, -1, 'd') ) );
+$db->where('id', Array(1, 5, 27, -1, 'd'), 'IN');
+//$db->where('id', Array(1, 5, 27, -1, 'd'), 'NOT IN');
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');
 ```
@@ -164,7 +164,7 @@ $results = $db->get('users');
 
 NULL comparison:
 ```php
-$db->where ("lastName", Array("<=>" => NULL));
+$db->where ("lastName", NULL, '<=>');
 $results = $db->get("users");
 // Gives: SELECT * FROM users where lastName <=> NULL
 ```
diff --git a/tests.php b/tests.php
index 275f354c..ce2adbf1 100644
--- a/tests.php
+++ b/tests.php
@@ -138,7 +138,7 @@ function createTable ($name, $data) {
 //$users = $db->get("users");
 //print_r ($users);
 
-$db->where("firstname", Array("LIKE" => '%John%'));
+$db->where("firstname", '%John%', 'LIKE');
 $users = $db->get("users");
 if ($db->count != 1) {
     echo "Invalid insert count in LIKE: ".$db->count;
@@ -172,14 +172,14 @@ function createTable ($name, $data) {
     exit;
 }
 
-$db->where ("id", Array('in' => Array('1','2','3')));
+$db->where ("id", Array('1','2','3'), 'IN');
 $db->get("users");
 if ($db->count != 3) {
     echo "Invalid users count on where() with in ";
     exit;
 }
 
-$db->where ("id", Array('between' => Array('2','3')));
+$db->where ("id", Array('2','3'), 'between');
 $db->get("users");
 if ($db->count != 2) {
     echo "Invalid users count on where() with between";
@@ -194,7 +194,7 @@ function createTable ($name, $data) {
     exit;
 }
 
-$db->where ("lastName", Array("<=>" => NULL));
+$db->where ("lastName", NULL, '<=>');
 $r = $db->get("users");
 if ($db->count != 1) {
     echo "Invalid users count on null where()";

From ad19105baf40a50a8cc889e10efc3266c39f3c2a Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Sat, 7 Jun 2014 14:34:34 +0300
Subject: [PATCH 12/22] Added insert subquery doc and a test

---
 readme.md | 48 ++++++++++++++++++++++++++++++++++++------------
 tests.php | 11 +++++++++++
 2 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/readme.md b/readme.md
index efd9f142..08463feb 100644
--- a/readme.md
+++ b/readme.md
@@ -10,7 +10,7 @@ After that, create a new instance of the class.
 $db = new Mysqlidb('host', 'username', 'password', 'databaseName');
 ```
 
-It's also possible to set a table prefix:
+Its also possible to set a table prefix:
 ```php
 $db->setPrefix('tablePrefix');
 ```
@@ -134,31 +134,35 @@ $results = $db->get('users');
 
 ```php
 $db->where('id', 50, ">=");
+// or $db->where('id', Array('>=' => 50));
+
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id >= 50;
 ```
 
-BETWEEN:
+BETWEEN / NOT BETWEEN:
 ```php
 $db->where('id', Array(4, 20), 'between');
-//$db->where('id', Array(4, 20), 'not between');
+// or $db->where('id', Array('between' => Array(4, 20) ) );
+
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id BETWEEN 4 AND 20
 ```
 
-IN:
+IN / NOT IN:
 ```php
 $db->where('id', Array(1, 5, 27, -1, 'd'), 'IN');
-//$db->where('id', Array(1, 5, 27, -1, 'd'), 'NOT IN');
+// or $db->where('id', Array( 'in' => Array(1, 5, 27, -1, 'd') ) );
+
 $results = $db->get('users');
 // Gives: SELECT * FROM users WHERE id IN (1, 5, 27, -1, 'd');
 ```
 
 OR CASE
 ```php
-$db->where('firstName','John');
-$db->orWhere('firstName','Peter');
-$results = $db->get('users');
+$db->where ('firstName', 'John');
+$db->orWhere ('firstName', 'Peter');
+$results = $db->get ('users');
 // Gives: SELECT * FROM users WHERE firstName='John' OR firstName='peter'
 ```
 
@@ -202,8 +206,8 @@ $results = $db->get('users');
 
 ### Grouping method
 ```php
-$db->groupBy("name");
-$results = $db->get('users');
+$db->groupBy ("name");
+$results = $db->get ('users');
 // Gives: SELECT * FROM users GROUP BY name;
 ```
 
@@ -217,12 +221,32 @@ print_r ($products);
 ```
 
 ### Subqueries
+Subquery in selects:
 ```php
-$ids = $db->subQuery()->where("qty", 2, ">")->get("products", null, "userId");
-$db->where("id", $ids, 'in');
+$ids = $db->subQuery ();
+$ids->where ("qty", 2, ">");
+$ids->get ("products", null, "userId");
+
+$db->where ("id", $ids, 'in');
 $res = $db->get ("users");
 // Gives SELECT * FROM users WHERE id IN (SELECT userId FROM products WHERE qty > 2)
 ```
+
+Subquery in inserts:
+```php
+$userIdQ = $db->subQuery ();
+$userIdQ->where ("id", 6);
+$userIdQ->getOne ("users", "name"),
+
+$data = Array (
+    "productName" => "test product",
+    "userId" => $userIdQ,
+    "lastUpdated" => $db->now()
+);
+$id = $db->insert ("products", $data);
+// Gives INSERT INTO PRODUCTS (productName, userId, lastUpdated) values ("test product", (SELECT name FROM users WHERE id = 6), NOW());
+```
+
 ### Helper commands
 Reconnect in case mysql connection died
 ```php
diff --git a/tests.php b/tests.php
index ce2adbf1..5235174a 100644
--- a/tests.php
+++ b/tests.php
@@ -224,6 +224,17 @@ function createTable ($name, $data) {
     exit;
 }
 
+$usersQ = $db->subQuery();
+$usersQ->where ("login", "user2");
+$usersQ->getOne ("users", "id");
+
+$db->where ("userId", $usersQ);
+$res = $db->getOne ("products", "count(id) as cnt");
+if ($res['cnt'] != 2) {
+    echo "Invalid select result with subquery";
+    exit;
+}
+//TODO: insert test
 $db->delete("users");
 $db->get("users");
 if ($db->count != 0) {

From f01c82ee72db22c3fa34e00d8c20b6b134a95086 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Sat, 7 Jun 2014 15:01:03 +0300
Subject: [PATCH 13/22] Bugfix: multiple conditions on the same key shouldnt
 overwrite previous condition

---
 MysqliDb.php | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 0b5a2e14..9b6f50de 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -362,7 +362,7 @@ public function where($whereProp, $whereValue = null, $operator = null)
         if ($operator)
             $whereValue = Array ($operator => $whereValue);
 
-        $this->_where[$whereProp] = Array ("AND", $whereValue);
+        $this->_where[] = Array ("AND", $whereValue, $whereProp);
         return $this;
     }
 
@@ -381,7 +381,7 @@ public function orWhere($whereProp, $whereValue = null, $operator = null)
         if ($operator)
             $whereValue = Array ($operator => $whereValue);
 
-        $this->_where[$whereProp] = Array ("OR", $whereValue);
+        $this->_where[] = Array ("OR", $whereValue, $whereProp);
         return $this;
     }
     /**
@@ -618,10 +618,11 @@ protected function _buildQuery($numRows = null, $tableData = null)
         if ($hasConditional) {
             //Prepair the where portion of the query
             $this->_query .= ' WHERE ';
-            foreach ($this->_where as $column => $value) {
-                //value[0] -- AND/OR, value[1] -- condition array
+            $i = 0;
+            foreach ($this->_where as $value) {
+                //value[0] -- AND/OR, value[1] -- condition array, value[2] -- key name
                 // if its not a first condition insert its concatenator (AND or OR)
-                if (array_search ($column, array_keys ($this->_where)) != 0)
+                if ($i != 0)
                     $this->_query .= ' ' . $value[0]. ' ';
 
                 if (is_array ($value[1])) {
@@ -663,7 +664,8 @@ protected function _buildQuery($numRows = null, $tableData = null)
                 } else {
                     $comparison = $this->_buildPair ("=", $value[1]);
                 }
-                $this->_query .= $column.$comparison;
+                $this->_query .= $value[2].$comparison;
+                $i++;
             }
         }
 

From e82a79619e0147fbb13b5fe7f48b2f53e13a2cdd Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Sun, 8 Jun 2014 01:51:38 +0300
Subject: [PATCH 14/22] Rename variable for better understanding

---
 MysqliDb.php | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 9b6f50de..6aed6239 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -619,21 +619,21 @@ protected function _buildQuery($numRows = null, $tableData = null)
             //Prepair the where portion of the query
             $this->_query .= ' WHERE ';
             $i = 0;
-            foreach ($this->_where as $value) {
-                //value[0] -- AND/OR, value[1] -- condition array, value[2] -- key name
+            foreach ($this->_where as $cond) {
+                //cond[0] -- AND/OR, cond[1] -- condition array, cond[2] -- key name
                 // if its not a first condition insert its concatenator (AND or OR)
                 if ($i != 0)
-                    $this->_query .= ' ' . $value[0]. ' ';
+                    $this->_query .= ' ' . $cond[0]. ' ';
 
-                if (is_array ($value[1])) {
-                    //value[0] -- AND/OR, value[1] -- condition array
+                if (is_array ($cond[1])) {
+                    //cond[0] -- AND/OR, cond[1] -- condition array
                     // if the value is an array, then this isn't a basic = comparison
-                    $key = key($value[1]);
-                    $val = $value[1][$key];
+                    $key = key($cond[1]);
+                    $val = $cond[1][$key];
                     switch( strtolower($key) ) {
                         case '0':
                             $comparison = '';
-                            foreach ($value[1] as $v)
+                            foreach ($cond[1] as $v)
                                 $this->_bindParam ($v);
                             break;
                         case 'not in':
@@ -659,12 +659,12 @@ protected function _buildQuery($numRows = null, $tableData = null)
                             // We are using a comparison operator with only one parameter after it
                             $comparison = $this->_buildPair ($key, $val);
                     }
-                } else if ($value[1] === null) {
+                } else if ($cond[1] === null) {
                     $comparison = '';
                 } else {
-                    $comparison = $this->_buildPair ("=", $value[1]);
+                    $comparison = $this->_buildPair ("=", $cond[1]);
                 }
-                $this->_query .= $value[2].$comparison;
+                $this->_query .= $cond[2].$comparison;
                 $i++;
             }
         }

From b8c5d3c584a5e06ea245f3ab93d8cd91effa0594 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Sun, 8 Jun 2014 01:51:38 +0300
Subject: [PATCH 15/22] Rename variable for better understanding

---
 MysqliDb.php | 32 ++++++++++++++------------------
 1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 9b6f50de..3baaee89 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -619,21 +619,19 @@ protected function _buildQuery($numRows = null, $tableData = null)
             //Prepair the where portion of the query
             $this->_query .= ' WHERE ';
             $i = 0;
-            foreach ($this->_where as $value) {
-                //value[0] -- AND/OR, value[1] -- condition array, value[2] -- key name
+            foreach ($this->_where as list($concat, $wValue, $wKey)) {
                 // if its not a first condition insert its concatenator (AND or OR)
-                if ($i != 0)
-                    $this->_query .= ' ' . $value[0]. ' ';
+                if ($i++ != 0)
+                    $this->_query .= " $concat ";
+                $this->_query .= $wKey;
 
-                if (is_array ($value[1])) {
-                    //value[0] -- AND/OR, value[1] -- condition array
+                if (is_array ($wValue)) {
                     // if the value is an array, then this isn't a basic = comparison
-                    $key = key($value[1]);
-                    $val = $value[1][$key];
+                    $key = key($wValue);
+                    $val = $wValue[$key];
                     switch( strtolower($key) ) {
                         case '0':
-                            $comparison = '';
-                            foreach ($value[1] as $v)
+                            foreach ($wValue as $v)
                                 $this->_bindParam ($v);
                             break;
                         case 'not in':
@@ -647,25 +645,23 @@ protected function _buildQuery($numRows = null, $tableData = null)
                                     $this->_bindParam ($v);
                                 }
                             }
-                            $comparison = rtrim($comparison, ',').' ) ';
+                            $this->_query .= rtrim($comparison, ',').' ) ';
                             break;
                         case 'not between':
                         case 'between':
-                            $comparison = ' ' . $key . ' ? AND ? ';
+                            $this->_query .= " $key ? AND ? ";
                             $this->_bindParam ($val[0]);
                             $this->_bindParam ($val[1]);
                             break;
                         default:
                             // We are using a comparison operator with only one parameter after it
-                            $comparison = $this->_buildPair ($key, $val);
+                            $this->_query .= $this->_buildPair ($key, $val);
                     }
-                } else if ($value[1] === null) {
-                    $comparison = '';
+                } else if ($wValue === null) {
+                    //
                 } else {
-                    $comparison = $this->_buildPair ("=", $value[1]);
+                    $this->_query .= $this->_buildPair ("=", $wValue);
                 }
-                $this->_query .= $value[2].$comparison;
-                $i++;
             }
         }
 

From 5e193ce050c100960a55a7442d2e1144892a01f8 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 12 Jun 2014 14:26:47 +0300
Subject: [PATCH 16/22] Added copy() method for properties sharing

---
 MysqliDb.php | 12 ++++++++++++
 readme.md    | 15 ++++++++++++++-
 tests.php    |  5 +++--
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 3baaee89..00d0dd6f 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -769,6 +769,8 @@ protected function _prepareQuery()
     public function __destruct()
     {
         if (!$this->isSubQuery)
+            return;
+        if ($this->_mysqli)
             $this->_mysqli->close();
     }
 
@@ -931,4 +933,14 @@ public static function subQuery()
         return new MysqliDb();
     }
 
+    /**
+     * Method returns a copy of a mysqlidb subquery object
+     *
+     * @param object new mysqlidb object
+     */
+    public function copy ()
+    {
+        return clone $this;
+    }
+
 } // END class
diff --git a/readme.md b/readme.md
index 08463feb..ffc27c6b 100644
--- a/readme.md
+++ b/readme.md
@@ -220,6 +220,20 @@ $products = $db->get ("products p", null, "u.name, p.productName");
 print_r ($products);
 ```
 
+### Properties sharing
+Its is also possible to copy properties
+```php
+$db->where ("agentId", 10);
+
+$customers = $common->copy ();
+$res = $customers->get ("customers");
+// SELECT * FROM customers where agentId = 10
+
+$db->orWhere ("agentId", 20);
+$res = $db->get ("users");
+// SELECT * FROM users where agentId = 10 or agentId = 20
+```
+
 ### Subqueries
 Subquery in selects:
 ```php
@@ -246,7 +260,6 @@ $data = Array (
 $id = $db->insert ("products", $data);
 // Gives INSERT INTO PRODUCTS (productName, userId, lastUpdated) values ("test product", (SELECT name FROM users WHERE id = 6), NOW());
 ```
-
 ### Helper commands
 Reconnect in case mysql connection died
 ```php
diff --git a/tests.php b/tests.php
index 5235174a..f6590186 100644
--- a/tests.php
+++ b/tests.php
@@ -228,8 +228,9 @@ function createTable ($name, $data) {
 $usersQ->where ("login", "user2");
 $usersQ->getOne ("users", "id");
 
-$db->where ("userId", $usersQ);
-$res = $db->getOne ("products", "count(id) as cnt");
+$db2 = $db->copy();
+$db2->where ("userId", $usersQ);
+$res = $db2->getOne ("products", "count(id) as cnt");
 if ($res['cnt'] != 2) {
     echo "Invalid select result with subquery";
     exit;

From a6f3e0516b38cb12d852cba2f78a8dd65d6ead63 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 12 Jun 2014 18:36:45 +0300
Subject: [PATCH 17/22] ups

---
 MysqliDb.php | 42 ++++++++++++++++++++++++++++++++++++++++++
 readme.md    | 15 +++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/MysqliDb.php b/MysqliDb.php
index 00d0dd6f..e5383d10 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -215,6 +215,48 @@ public function rawQuery($query, $bindParams = null)
         return $this->_dynamicBindResults($stmt);
     }
 
+    /**
+     * Pass in an array of subqueries for union query construction.
+     *
+     * @param array $objects Contains a user-provided array of subqueries
+     * @param $type 'ALL', 'DISTINCT', null.
+     *
+     * @return array Contains the returned rows from the query.
+     */
+    public function union ($objects, $type = null)
+    {
+        $allowedTypes = array('ALL', 'DISTINCT');
+        $type = strtoupper (trim ($type));
+
+        if ($type && !in_array ($type, $allowedTypes))
+            die ('Wrong UNION type: '.$type);
+
+        if (!is_array ($objects))
+            return;
+
+        $this->_query = "";
+        $i = 0;
+        foreach ($objects as $obj) {
+            if (!is_object ($obj))
+                continue;
+
+            if ($i++ != 0)
+                $this->_query .= " UNION {$type} ";
+
+            $subQuery = $obj->getSubQuery();
+            $this->_query .= "(" . $subQuery['query'] . ")";
+            foreach ($subQuery['params'] as $v)
+                $this->_bindParam ($v);
+        }
+        $stmt = $this->_buildQuery (null);
+        $stmt->execute();
+        $this->_stmtError = $stmt->error;
+        $this->reset();
+
+        return $this->_dynamicBindResults($stmt);
+    }
+
+
     /**
      *
      * @param string $query   Contains a user-provided select query.
diff --git a/readme.md b/readme.md
index ffc27c6b..fce150f3 100644
--- a/readme.md
+++ b/readme.md
@@ -260,6 +260,21 @@ $data = Array (
 $id = $db->insert ("products", $data);
 // Gives INSERT INTO PRODUCTS (productName, userId, lastUpdated) values ("test product", (SELECT name FROM users WHERE id = 6), NOW());
 ```
+UNION queries
+```php
+$common = $db->subQuery();
+$common->where ("agentId", 10);
+
+$customers = $common->copy();
+$customers->get ("customers");
+
+$users = $common->copy();
+$users->get ("users");
+
+$db->orderBy ("lastModified");
+$res = $db->union (Array ($customers, $users, $companies), "ALL");
+GIVES (SELECT * FROM customers WHERE agentId = 10 ) UNION ALL (SELECT * FROM users WHERE agentId = 10 ) ORDER BY lastModified DESC
+```
 ### Helper commands
 Reconnect in case mysql connection died
 ```php

From c9b6198fedcd60a6406f17ce98deb0d31c4afee7 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 12 Jun 2014 18:37:24 +0300
Subject: [PATCH 18/22] Revert "ups"

This reverts commit a6f3e0516b38cb12d852cba2f78a8dd65d6ead63.
---
 MysqliDb.php | 42 ------------------------------------------
 readme.md    | 15 ---------------
 2 files changed, 57 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index e5383d10..00d0dd6f 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -215,48 +215,6 @@ public function rawQuery($query, $bindParams = null)
         return $this->_dynamicBindResults($stmt);
     }
 
-    /**
-     * Pass in an array of subqueries for union query construction.
-     *
-     * @param array $objects Contains a user-provided array of subqueries
-     * @param $type 'ALL', 'DISTINCT', null.
-     *
-     * @return array Contains the returned rows from the query.
-     */
-    public function union ($objects, $type = null)
-    {
-        $allowedTypes = array('ALL', 'DISTINCT');
-        $type = strtoupper (trim ($type));
-
-        if ($type && !in_array ($type, $allowedTypes))
-            die ('Wrong UNION type: '.$type);
-
-        if (!is_array ($objects))
-            return;
-
-        $this->_query = "";
-        $i = 0;
-        foreach ($objects as $obj) {
-            if (!is_object ($obj))
-                continue;
-
-            if ($i++ != 0)
-                $this->_query .= " UNION {$type} ";
-
-            $subQuery = $obj->getSubQuery();
-            $this->_query .= "(" . $subQuery['query'] . ")";
-            foreach ($subQuery['params'] as $v)
-                $this->_bindParam ($v);
-        }
-        $stmt = $this->_buildQuery (null);
-        $stmt->execute();
-        $this->_stmtError = $stmt->error;
-        $this->reset();
-
-        return $this->_dynamicBindResults($stmt);
-    }
-
-
     /**
      *
      * @param string $query   Contains a user-provided select query.
diff --git a/readme.md b/readme.md
index fce150f3..ffc27c6b 100644
--- a/readme.md
+++ b/readme.md
@@ -260,21 +260,6 @@ $data = Array (
 $id = $db->insert ("products", $data);
 // Gives INSERT INTO PRODUCTS (productName, userId, lastUpdated) values ("test product", (SELECT name FROM users WHERE id = 6), NOW());
 ```
-UNION queries
-```php
-$common = $db->subQuery();
-$common->where ("agentId", 10);
-
-$customers = $common->copy();
-$customers->get ("customers");
-
-$users = $common->copy();
-$users->get ("users");
-
-$db->orderBy ("lastModified");
-$res = $db->union (Array ($customers, $users, $companies), "ALL");
-GIVES (SELECT * FROM customers WHERE agentId = 10 ) UNION ALL (SELECT * FROM users WHERE agentId = 10 ) ORDER BY lastModified DESC
-```
 ### Helper commands
 Reconnect in case mysql connection died
 ```php

From 4f93e79346f0270b7d8d7c7c533c45b24138d74e Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Tue, 17 Jun 2014 03:13:04 +0300
Subject: [PATCH 19/22] Fix typo

---
 readme.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/readme.md b/readme.md
index ffc27c6b..f4676963 100644
--- a/readme.md
+++ b/readme.md
@@ -225,7 +225,7 @@ Its is also possible to copy properties
 ```php
 $db->where ("agentId", 10);
 
-$customers = $common->copy ();
+$customers = $db->copy ();
 $res = $customers->get ("customers");
 // SELECT * FROM customers where agentId = 10
 

From 9e7856399c7f04df72472aa50c2191c8d7cb287f Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 19 Jun 2014 13:18:13 +0300
Subject: [PATCH 20/22] Added transaction helpers

---
 MysqliDb.php | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 readme.md    | 15 +++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/MysqliDb.php b/MysqliDb.php
index 00d0dd6f..cafe2a3e 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -943,4 +943,53 @@ public function copy ()
         return clone $this;
     }
 
+    /**
+     * Begin a transaction
+     *
+     * @uses mysqli->autocommit(false)
+     * @uses register_shutdown_function(array($this, "_transaction_shutdown_check"))
+     */
+    public function startTransaction () {
+        $this->_mysqli->autocommit (false);
+        $this->_transaction_in_progress = true;
+        register_shutdown_function (array ($this, "_transaction_status_check"));
+    }
+
+    /**
+     * Transaction commit
+     *
+     * @uses mysqli->commit();
+     * @uses mysqli->autocommit(true);
+     */
+    public function commit () {
+        $this->_mysqli->commit ();
+        $this->_transaction_in_progress = false;
+        $this->_mysqli->autocommit (true);
+    }
+
+    /**
+     * Transaction rollback function
+     *
+     * @uses mysqli->rollback();
+     * @uses mysqli->autocommit(true);
+     */
+    public function rollback () {
+      $this->_mysqli->rollback ();
+      $this->_transaction_in_progress = false;
+      $this->_mysqli->autocommit (true);
+    }
+
+    /**
+     * Shutdown handler to rollback uncommited operations in order to keep
+     * atomic operations sane.
+     *
+     * @uses mysqli->rollback();
+     */
+    public function _transaction_status_check () {
+        if (!$this->_transaction_in_progress)
+            return;
+
+        echo "rolling all back";
+        $this->rollback ();
+    }
 } // END class
diff --git a/readme.md b/readme.md
index f4676963..64749db8 100644
--- a/readme.md
+++ b/readme.md
@@ -278,3 +278,18 @@ Please note that function returns SQL query only for debugging purposes as its e
     $db->get('users');
     echo "Last executed query was ". $db->getLastQuery();
 ```
+
+### Transaction helpers
+Please keep in mind that transactions are working on innoDB tables.
+Rollback transaction if insert fails:
+```php
+$db->startTransaction();
+...
+if (!$db->insert ('myTable', $insertData)) {
+    //Error while saving, cancel new record
+    $db->rollback();
+} else {
+    //OK
+    $db->commit();
+}
+```

From fd69e015fd1da6835c36e123d9ef312c4a2b3684 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 19 Jun 2014 13:19:50 +0300
Subject: [PATCH 21/22] removed debug junk

---
 MysqliDb.php | 2 --
 1 file changed, 2 deletions(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index cafe2a3e..3be57369 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -988,8 +988,6 @@ public function rollback () {
     public function _transaction_status_check () {
         if (!$this->_transaction_in_progress)
             return;
-
-        echo "rolling all back";
         $this->rollback ();
     }
 } // END class

From ce7d9e8bee9288d3c8456fe58107e583386c6713 Mon Sep 17 00:00:00 2001
From: Alexander Butenko <a.butenka@gmail.com>
Date: Thu, 26 Jun 2014 17:56:46 +0300
Subject: [PATCH 22/22] rawQuery: do not escape quotes

---
 MysqliDb.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MysqliDb.php b/MysqliDb.php
index 3be57369..fc188bd5 100644
--- a/MysqliDb.php
+++ b/MysqliDb.php
@@ -193,7 +193,7 @@ public function setPrefix($prefix = '')
      */
     public function rawQuery($query, $bindParams = null)
     {
-        $this->_query = filter_var ($query, FILTER_SANITIZE_MAGIC_QUOTES,
+        $this->_query = filter_var ($query, FILTER_SANITIZE_STRING,
                                     FILTER_FLAG_NO_ENCODE_QUOTES);
         $stmt = $this->_prepareQuery();