Added support for parameterized virtual tables

Author: rkrx

doc/virtual-tables.md

@@ -1,5 +1,7 @@
 # Virtual tables
 
+## Unparameterized virtual tables
+
 First define virtual tables somewhere in your bootstrap:
 
 ```php
@@ -33,4 +35,42 @@ $query = $db->select()
 ->joinInner('vt2', 'virt_table2', 'vt2.field2=t.field2');
 ```
 
+## Parameterized virtual tables
+
+When you need parameterized sub-selects, you can use the Helperclass `Kir\MySQL\Tools\VirtualTable` to add parameters to a table-name:
+
+Definition:
+
+```php
+use Kir\MySQL\Databases\MySQL;
+
+$db = new MySQL($pdo);
+
+$vt1 = $db->select()
+->field('a.field1')
+->from('a', 'tableA');
+
+$db->getVirtualTables()->add('virt_table1', $vt1);
+
+// Lazy evaluated; parameterized
+$db->getVirtualTables()->add('virt_table2', function (array $args) {
+	return $db->select()
+	->field('a.field1')
+	->from('a', 'tableA')
+	->where(new DBExprFilter('a.active=?', $args, 'active'));
+});
+```
+
+Then use it as needed:
+
+```php
+$query = $db->select()
+->field('t.field1')
+->field('vt1.fieldN')
+->field('vt2.fieldN')
+->from('t', 'test')
+->joinInner('vt1', 'virt_table1', 'vt1.field1=t.field1')
+->joinInner('vt2', new VirtualTable('virt_table2', ['active' => 1]), 'vt2.field2=t.field2');
+```
+
 [Back](../README.md)

src/Builder/Traits/TableNameBuilder.php

@@ -2,6 +2,7 @@
 namespace Kir\MySQL\Builder\Traits;
 
 use Kir\MySQL\Databases\MySQL;
+use Kir\MySQL\Tools\VirtualTable;
 
 trait TableNameBuilder {
 	use AbstractAliasReplacer;
@@ -12,7 +13,7 @@ trait TableNameBuilder {
 	 * @return string
 	 */
 	protected function buildTableName($alias, $name) {
-		if(is_object($name)) {
+		if(is_object($name) && !($name instanceof VirtualTable)) {
 			$name = (string) $name;
 			$lines = explode("\n", $name);
 			foreach($lines as &$line) {
@@ -33,7 +34,7 @@ protected function buildTableName($alias, $name) {
 			$name = '(' . join("\n\tUNION\n\t", $parts) . ')';
 		}
 		if($this->db()->getVirtualTables()->has($name)) {
-			$select = (string )$this->db()->getVirtualTables()->get($name);
+			$select = (string) $this->db()->getVirtualTables()->get($name);
 			$name = sprintf('(%s)', join("\n\t", explode("\n", trim($select))));
 		}
 		$name = $this->aliasReplacer()->replace($name);

src/Tools/VirtualTable.php

@@ -0,0 +1,39 @@
+<?php
+namespace Kir\MySQL\Tools;
+
+class VirtualTable {
+	/** @var string */
+	private $tableName;
+	/** @var array */
+	private $params = [];
+	
+	/**
+	 * @param string $tableName
+	 * @param array $params
+	 */
+	public function __construct($tableName, array $params = []) {
+		$this->tableName = $tableName;
+		$this->params = $params;
+	}
+	
+	/**
+	 * @return string
+	 */
+	public function getTableName() {
+		return $this->tableName;
+	}
+	
+	/**
+	 * @return array
+	 */
+	public function getParams() {
+		return $this->params;
+	}
+	
+	/**
+	 * @return string
+	 */
+	public function __toString() {
+		return $this->getTableName();
+	}
+}

src/Tools/VirtualTables.php

@@ -18,11 +18,11 @@ public function add($tableName, $select) {
 	}
 
 	/**
-	 * @param string $tableName
+	 * @param string|VirtualTable $tableName
 	 * @return bool
 	 */
 	public function has($tableName) {
-		return array_key_exists($tableName, $this->virtualTables);
+		return array_key_exists((string) $tableName, $this->virtualTables);
 	}
 
 	/**
@@ -31,9 +31,13 @@ public function has($tableName) {
 	 */
 	public function get($tableName) {
 		if($this->has($tableName)) {
-			$table = $this->virtualTables[$tableName];
+			$table = $this->virtualTables[(string) $tableName];
 			if($table instanceof \Closure) {
-				return call_user_func($table);
+				$params = [];
+				if($tableName instanceof VirtualTable) {
+					$params = $tableName->getParams();
+				}
+				return call_user_func($table, $params);
 			}
 			return $table;
 		}

tests/Builder/SelectTest.php

@@ -8,6 +8,7 @@
 use Kir\MySQL\Builder\Expr\RequiredValueNotFoundException;
 use Kir\MySQL\Builder\SelectTest\TestSelect;
 use Kir\MySQL\Databases\TestDB;
+use Kir\MySQL\Tools\VirtualTable;
 
 class SelectTestX extends \PHPUnit_Framework_TestCase {
 	public function testAddition() {
@@ -365,4 +366,29 @@ public function testVirtualTables() {
 
 		$this->assertEquals("SELECT\n\tt.field1,\n\tt.field2\nFROM\n\ttest t\nINNER JOIN\n\t(SELECT\n\t\ta.field1\n\tFROM\n\t\ttableA a) vt1 ON vt1.field1=t.field1\nINNER JOIN\n\t(SELECT\n\t\ta.field1\n\tFROM\n\t\ttableA a) vt2 ON vt2.field2=t.field2\n", $query);
 	}
+
+	public function testParametrizedVirtualTables() {
+		$vt1 = TestSelect::create()
+		->field('a.field1')
+		->from('a', 'tableA');
+		
+		$db = new TestDB();
+		$db->getVirtualTables()->add('virt_table1', $vt1);
+		$db->getVirtualTables()->add('virt_table2', function (array $args) {
+			return TestSelect::create()
+			->field('a.field1')
+			->from('a', 'tableA')
+			->where(new DBExprFilter('a.active=?', $args, 'active'));
+		});
+		
+		$query = TestSelect::create($db)
+		->field('t.field1')
+		->field('t.field2')
+		->from('t', 'test')
+		->joinInner('vt1', 'virt_table1', 'vt1.field1=t.field1')
+		->joinInner('vt2', new VirtualTable('virt_table2', ['active' => true]), 'vt2.field2=t.field2')
+		->asString();
+
+		$this->assertEquals("SELECT\n\tt.field1,\n\tt.field2\nFROM\n\ttest t\nINNER JOIN\n\t(SELECT\n\t\ta.field1\n\tFROM\n\t\ttableA a) vt1 ON vt1.field1=t.field1\nINNER JOIN\n\t(SELECT\n\t\ta.field1\n\tFROM\n\t\ttableA a\n\tWHERE\n\t\t(a.active='1')) vt2 ON vt2.field2=t.field2\n", $query);
+	}
 }