Added support for COUNT queries

README.markdown

@@ -87,6 +87,12 @@ To find all records where the `gender` is `female`:
 
     $females = ORM::for_table('person')->where('gender', 'female')->find_many();
 
+#### Counting results ####
+
+To return a count of the number of rows that would be returned by a query, call the `count()` method.
+
+    $number_of_people = ORM::for_table('person')->count();
+
 #### WHERE clauses ####
 
 The `where` method on the ORM class adds a single `WHERE` clause to your query. The method may be called (chained) multiple times to add more than one `WHERE` clause. All the `WHERE` clauses will be `AND`ed together when the query is run. Support for `OR`ing `WHERE` clauses is not currently present; if a query requires an `OR` operator you should use the `where_raw` or `raw_select` methods (see below).

demo.php

@@ -48,6 +48,7 @@
     }
 
     // Get a list of all contacts from the database
+    $count = ORM::for_table('contact')->count();
     $contact_list = ORM::for_table('contact')->find_many();
 ?>
 
@@ -60,7 +61,7 @@
 
         <h1>Idiorm Demo</h1>
 
-        <h2>Contact List</h2>
+        <h2>Contact List (<?php echo $count; ?> contacts)</h2>
         <ul>
             <?php foreach ($contact_list as $contact): ?>
                 <li>

idiorm.php

@@ -51,6 +51,7 @@ class ORM {
         // Find types
         const FIND_ONE = 0;
         const FIND_MANY = 1;
+        const COUNT = 2;
 
         // Update or insert?
         const UPDATE = 0;
@@ -266,6 +267,16 @@ public function find_many() {
             return $this->run();
         }
 
+        /**
+         * Tell the ORM that you wish to execute a COUNT query.
+         * Will return an integer representing the number of
+         * rows returned.
+         */
+        public function count() {
+            $this->find_type = self::COUNT;
+            return $this->run();
+        }
+
          /**
          * This method can be called hydrate (populate) this
          * instance of the class from an associative array of data.
@@ -395,7 +406,12 @@ private function build_select() {
             }
 
             $query = array();
-            $query[] = 'SELECT * FROM ' . $this->table_name;
+
+            if ($this->find_type === self::COUNT) {
+                $query[] = 'SELECT COUNT(*) AS count FROM ' . $this->table_name;
+            } else {
+                $query[] = 'SELECT * FROM ' . $this->table_name;
+            }
 
             if ($this->where_is_raw) { // Raw WHERE clause
                 $query[] = "WHERE";
@@ -458,15 +474,19 @@ private function run() {
             $statement = self::$db->prepare($this->build_select());
             $statement->execute($this->values);
 
-            if ($this->find_type == self::FIND_ONE) {
-                $result = $statement->fetch(PDO::FETCH_ASSOC);
-                return $result ? self::for_table($this->table_name)->hydrate($result) : $result;
-            } else {
-                $instances = array();
-                while ($row = $statement->fetch(PDO::FETCH_ASSOC)) {
-                    $instances[] = self::for_table($this->table_name)->hydrate($row);
-                }
-                return $instances;
+            switch ($this->find_type) {
+                case self::FIND_ONE:
+                    $result = $statement->fetch(PDO::FETCH_ASSOC);
+                    return $result ? self::for_table($this->table_name)->hydrate($result) : $result;
+                case self::FIND_MANY:
+                    $instances = array();
+                    while ($row = $statement->fetch(PDO::FETCH_ASSOC)) {
+                        $instances[] = self::for_table($this->table_name)->hydrate($row);
+                    }
+                    return $instances;
+                case self::COUNT:
+                    $result = $statement->fetch(PDO::FETCH_ASSOC);
+                    return isset($result['count']) ? (int) $result['count'] : 0;
             }
         }
 

test/test_queries.php

@@ -22,6 +22,10 @@
     $expected = 'SELECT * FROM widget WHERE id = "5"';
     Tester::check_equal("Filtering on ID", $expected);
 
+    ORM::for_table('widget')->count();
+    $expected = 'SELECT COUNT(*) AS count FROM widget';
+    Tester::check_equal("COUNT query", $expected);
+
     ORM::for_table('widget')->where('name', 'Fred')->find_one();
     $expected = 'SELECT * FROM widget WHERE name = "Fred"';
     Tester::check_equal("Single where clause", $expected);