Add seed values support for Query Builder order_by

(feature request #1987)

9 files changed, 69 insertions, 11 deletions

diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index 4f762b91c..5a87cf0c7 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -55,6 +55,13 @@ class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver {
 	 */
 	protected $_escape_char = '`';
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	array
+	 */
+	protected $_random_keyword = array('RANDOM()', 'RANDOM(%d)');
+
 	// --------------------------------------------------------------------
 
 	/**
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 7121819ec..a44fd3afc 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -53,9 +53,9 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
-	protected $_random_keyword = ' NEWID()';
+	protected $_random_keyword = array('NEWID()', 'RAND(%d)');
 
 	/**
 	 * Quoted identifier flag
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index 83b9648c1..7c3836691 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -53,9 +53,9 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
-	protected $_random_keyword = ' RANDOM()';
+	protected $_random_keyword = array('RAND()', 'RAND()');
 
 	// --------------------------------------------------------------------
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index 8998670e1..03886f442 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -51,6 +51,15 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	array
+	 */
+	protected $_random_keyword = array('ASC', 'ASC'); // Currently not supported
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Class constructor
 	 *
 	 * Builds the DSN if not already set.
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index e1beb3683..051b7dec8 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -62,9 +62,9 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
-	protected $_random_keyword = ' ASC'; // Currently not supported
+	protected $_random_keyword = array('ASC', 'ASC'); // Currently not supported
 
 	/**
 	 * COUNT string
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index f6e0e215a..05b34fa89 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -73,6 +73,13 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 */
 	protected $_like_escape_str = " {escape '%s'} ";
 
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	array
+	 */
+	protected $_random_keyword = array('RND()', 'RND(%d)');
+
 	// --------------------------------------------------------------------
 
 	/**
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index c3f5b7603..45165213f 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -60,9 +60,9 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
-	protected $_random_keyword = ' RANDOM()';
+	protected $_random_keyword = array('RANDOM()', 'RANDOM()');
 
 	// --------------------------------------------------------------------
 
@@ -110,6 +110,41 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * ORDER BY
+	 *
+	 * @param	string	$orderby
+	 * @param	string	$direction	ASC or DESC
+	 * @param	bool	$escape
+	 * @return	object
+	 */
+	public function order_by($orderby, $direction = '', $escape = NULL)
+	{
+		$direction = strtoupper(trim($direction));
+		if ($direction === 'RANDOM')
+		{
+			if ( ! is_float($orderby) && ctype_digit((string) $orderby))
+			{
+				$orderby = ($orderby > 1)
+					? (float) '0.'.$orderby
+					: (float) $orderby;
+			}
+
+			if (is_float($orderby))
+			{
+				$this->simple_query('SET SEED '.$orderby);
+			}
+
+			$orderby = $this->_random_keyword[0];
+			$direction = '';
+			$escape = FALSE;
+		}
+
+		return parent::order_by($orderby, $direction, $escape);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Show table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index b24b13e76..f9d186f6c 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -53,7 +53,7 @@ class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
 	protected $_random_keyword = ' RANDOM()';
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index 7bb7f8806..1a630729d 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -53,9 +53,9 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	/**
 	 * ORDER BY random keyword
 	 *
-	 * @var	string
+	 * @var	array
 	 */
-	protected $_random_keyword = ' NEWID()';
+	protected $_random_keyword = array('NEWID()', 'RAND(%d)');
 
 	/**
 	 * Quoted identifier flag