Added 'distinct' method to query builder

README.md

@@ -45,7 +45,7 @@ Create a connection array or object similar to this:
 The parameters required depend on the database. 
 
 ### Running Queries
-Query uses the same interface as CodeIgniter's [Active Record class](http://codeigniter.com/user_guide/database/active_record.html). However, it does not implement the `count_all_results`, `distinct`, `having`, `or_having`, `insert_batch`, `update_batch`, or `count_all` methods.
+Query uses the same interface as CodeIgniter's [Active Record class](http://codeigniter.com/user_guide/database/active_record.html). However, it does not implement the `count_all_results`, `having`, `or_having`, `insert_batch`, `update_batch`, or `count_all` methods.
 
 #### Retrieving Results
 

classes/db_reg.php

@@ -57,6 +57,16 @@ class DB_Reg {
 	
 	// --------------------------------------------------------------------------
 	
+	/**
+	 * Cleanup method
+	 */
+	public function __destruct()
+	{
+		unset(self::$instance);
+	}
+
+	// --------------------------------------------------------------------------
+
 	/**
 	 * Return exiting connections
 	 *

classes/query_builder.php

@@ -19,7 +19,7 @@
 class Query_Builder {
 
 	// Compiled query component strings
-	private $select_string,
+	private $select_string = '',
 		$from_string,
 		$set_string,
 		$order_string,
@@ -171,7 +171,7 @@ class Query_Builder {
 			}
 		}
 
-		$this->select_string = implode(', ', $safe_array);
+		$this->select_string .= implode(', ', $safe_array);
 
 		unset($safe_array);
 
@@ -197,7 +197,7 @@ class Query_Builder {
 			: $field;
 			
 		// Create the select string
-		$this->select_string = $this->sql->max()."({$field}) AS {$as} ";
+		$this->select_string .= $this->sql->max()."({$field}) AS {$as} ";
 		
 		return $this;
 	}
@@ -221,7 +221,7 @@ class Query_Builder {
 			: $field;
 			
 		// Create the select string
-		$this->select_string = $this->sql->min()."({$field}) AS {$as} ";
+		$this->select_string .= $this->sql->min()."({$field}) AS {$as} ";
 		
 		return $this;
 	}
@@ -245,7 +245,7 @@ class Query_Builder {
 			: $field;
 			
 		// Create the select string
-		$this->select_string = $this->sql->avg()."({$field}) AS {$as} ";
+		$this->select_string .= $this->sql->avg()."({$field}) AS {$as} ";
 		
 		return $this;
 	}
@@ -269,7 +269,22 @@ class Query_Builder {
 			: $field;
 			
 		// Create the select string
-		$this->select_string = $this->sql->sum()."({$field}) AS {$as} ";
+		$this->select_string .= $this->sql->sum()."({$field}) AS {$as} ";
+		
+		return $this;
+	}
+
+	// --------------------------------------------------------------------------
+	
+	/**
+	 * Adds the 'distinct' keyword to a query
+	 *
+	 * @return $this
+	 */
+	public function distinct()
+	{
+		// Prepend the keyword to the select string
+		$this->select_string = $this->sql->distinct() . $this->select_string;
 		
 		return $this;
 	}
@@ -1119,11 +1134,15 @@ class Query_Builder {
 			// Nothing query-generation related is safe!
 			if ( ! is_callable($this->$name))
 			{
-				unset($this->$name);
+				$this->$name = NULL;
 			}
 
 			// Set values as an empty array
 			$this->values = array();
+			
+			// Set select string as an empty string, for proper handling
+			// of the 'distinct' keyword
+			$this->select_string = '';
 		}
 	}
 
@@ -1216,6 +1235,8 @@ class Query_Builder {
 			break;
 		}
 		
+		// echo $sql . '<br />';
+
 		return $sql;
 	}
 }

tests/core/db_qb_test.php

@@ -12,46 +12,6 @@
 
 // --------------------------------------------------------------------------
 
-/**
- * Parent Database Test Class
- */
-abstract class DBTest extends UnitTestCase {
-
-	abstract function TestConnection();
-
-	function tearDown()
-	{
-		$this->db = NULL;
-	}
-
-	function TestGetTables()
-	{
-		if (empty($this->db))  return;
-
-		$tables = $this->db->get_tables();
-		$this->assertTrue(is_array($tables));
-	}
-
-	function TestGetSystemTables()
-	{
-		if (empty($this->db))  return;
-
-		$tables = $this->db->get_system_tables();
-
-		$this->assertTrue(is_array($tables));
-	}
-
-	function TestCreateTransaction()
-	{
-		if (empty($this->db))  return;
-
-		$res = $this->db->beginTransaction();
-		$this->assertTrue($res);
-	}
-}
-
-// --------------------------------------------------------------------------
-
 /**
  * Query builder parent test class
  */
@@ -147,6 +107,17 @@ abstract class QBTest extends UnitTestCase {
 		$this->assertIsA($query, 'PDOStatement');
 	}
 	
+	function TestSelectDistinct()
+	{
+		if (empty($this->db))  return;
+	
+		$query = $this->db->select_sum('id', 'di')
+			->distinct()
+			->get('create_test');
+			
+		$this->assertIsA($query, 'PDOStatement');
+	}
+	
 	function TestGetWhere()
 	{
 		if (empty($this->db))  return;
@@ -319,4 +290,4 @@ abstract class QBTest extends UnitTestCase {
 	}
 }
 
-// End of parent.php
+// End of db_qb_test.php

tests/core/db_test.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * Query
+ *
+ * Free Query Builder / Database Abstraction Layer
+ *
+ * @author 		Timothy J. Warren
+ * @copyright	Copyright (c) 2012
+ * @link 		https://github.com/aviat4ion/Query
+ * @license 	http://philsturgeon.co.uk/code/dbad-license 
+ */
+
+// --------------------------------------------------------------------------
+
+/**
+ * Parent Database Test Class
+ */
+abstract class DBTest extends UnitTestCase {
+
+	abstract function TestConnection();
+
+	function tearDown()
+	{
+		$this->db = NULL;
+	}
+
+	function TestGetTables()
+	{
+		if (empty($this->db))  return;
+
+		$tables = $this->db->get_tables();
+		$this->assertTrue(is_array($tables));
+	}
+
+	function TestGetSystemTables()
+	{
+		if (empty($this->db))  return;
+
+		$tables = $this->db->get_system_tables();
+
+		$this->assertTrue(is_array($tables));
+	}
+
+	function TestCreateTransaction()
+	{
+		if (empty($this->db))  return;
+
+		$res = $this->db->beginTransaction();
+		$this->assertTrue($res);
+	}
+}
+// End of db_test.php

tests/databases/firebird/firebird-qb.php

@@ -116,6 +116,17 @@ class FirebirdQBTest extends QBTest {
 		$this->assertIsA($query, 'Firebird_Result');
 	}
 	
+	function TestSelectDistinct()
+	{
+		if (empty($this->db))  return;
+	
+		$query = $this->db->select_sum('id', 'di')
+			->distinct()
+			->get('create_test');
+			
+		$this->assertIsA($query, 'Firebird_Result');
+	}
+	
 	function TestGetWhere()
 	{
 		if (empty($this->db))  return;

tests/index.php

@@ -27,7 +27,10 @@ require_once('simpletest/autorun.php');
 require_once(BASE_DIR . 'autoload.php');
 
 // Require base testing classes
-array_map('do_include', glob(TEST_DIR . "/core/*.php"));
+require_once(TEST_DIR . '/core/core.php');
+require_once(TEST_DIR . '/core/settings.php');
+require_once(TEST_DIR . '/core/db_test.php');
+require_once(TEST_DIR . '/core/db_qb_test.php');
 
 // Include db tests
 // Load db classes based on capability