From 955537cdb726c33890598c485524c80787d085b6 Mon Sep 17 00:00:00 2001
From: Timothy Warren <tim@timshomepage.net>
Date: Wed, 29 Feb 2012 18:33:21 -0500
Subject: [PATCH] Added limit clause to db drivers

---
 sys/common/db_pdo.php          | 12 ++++++++++--
 sys/databases/firebird_sql.php | 25 +++++++++++++++++++++++++
 sys/databases/mysql_sql.php    | 18 ++++++++++++++++++
 sys/databases/odbc_sql.php     | 13 +++++++++++++
 sys/databases/pgsql_sql.php    | 20 ++++++++++++++++++++
 sys/databases/sqlite_sql.php   | 18 +++++++++++-------
 6 files changed, 97 insertions(+), 9 deletions(-)

diff --git a/sys/common/db_pdo.php b/sys/common/db_pdo.php
index d295f78..72d940c 100644
--- a/sys/common/db_pdo.php
+++ b/sys/common/db_pdo.php
@@ -213,7 +213,6 @@ abstract class DB_SQL {
 	 * @param array $columns 
 	 * @param array $constraints 
 	 * @param array $indexes 
-	 * 
 	 * @return string
 	 */
 	abstract public function create_table($name, $columns, $constraints=array(), $indexes=array());
@@ -222,11 +221,20 @@ abstract class DB_SQL {
 	 * Get database-specific sql to drop a table
 	 * 
 	 * @param string $name
-	 * 
 	 * @return string
 	 */
 	abstract public function delete_table($name);
 
+	/**
+	 * Get database specific sql for limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limiit
+	 * @param int $offset
+	 * @return string
+	 */
+	abstract public function limit($sql, $limit, $offset);
+
 	
 }
 // End of db_pdo.php
\ No newline at end of file
diff --git a/sys/databases/firebird_sql.php b/sys/databases/firebird_sql.php
index 800a749..83b1638 100644
--- a/sys/databases/firebird_sql.php
+++ b/sys/databases/firebird_sql.php
@@ -85,5 +85,30 @@ class Firebird_SQL extends DB_SQL {
 	{
 		return 'DROP TABLE "'.$name.'"';
 	}
+
+	/**
+	 * Limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limit
+	 * @param int $offset
+	 * @return string
+	 */
+	public function limit($sql, $limit, $offset=FALSE)
+	{
+		// Keep the current sql string safe for a moment
+		$orig_sql = $sql;
+	
+		$sql = 'FIRST '. (int) $limit;
+		
+		if ($offset > 0)
+		{
+			$sql .= ' SKIP'. (int) $offset;
+		}
+		
+		$sql = preg_replace("`SELECT`i", "SELECT {$sql}", $orig_sql);
+		
+		return $sql;
+	} 
 }
 //End of firebird_sql.php
\ No newline at end of file
diff --git a/sys/databases/mysql_sql.php b/sys/databases/mysql_sql.php
index cc77203..ee4ad3b 100644
--- a/sys/databases/mysql_sql.php
+++ b/sys/databases/mysql_sql.php
@@ -41,6 +41,24 @@
 	public function delete_table($name)
 	{
 		return "DROP TABLE `{$name}`";
+	}
+
+	/**
+	 * Limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limit
+	 * @param int $offset
+	 * @return string
+	 */
+	public function limit($sql, $limit, $offset=FALSE)
+	{
+		if ( ! is_numeric($offset))
+		{
+			return $sql." LIMIT {$limit}";
+		}
+
+		return $sql." LIMIT {$offset}, {$limit}";
 	}	
 }
 //End of mysql_sql.php
\ No newline at end of file
diff --git a/sys/databases/odbc_sql.php b/sys/databases/odbc_sql.php
index b6dfa47..6567ab5 100644
--- a/sys/databases/odbc_sql.php
+++ b/sys/databases/odbc_sql.php
@@ -27,5 +27,18 @@ class ODBC_SQL extends DB_SQL {
 	{
 		return "DROP TABLE {$name}";
 	}
+
+	/**
+	 * Limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limit
+	 * @param int $offset
+	 * @return string
+	 */
+	public function limit($sql, $limit, $offset=FALSE)
+	{
+		
+	}
 }
 // End of odbc_sql.php
\ No newline at end of file
diff --git a/sys/databases/pgsql_sql.php b/sys/databases/pgsql_sql.php
index c530d54..2c673a6 100644
--- a/sys/databases/pgsql_sql.php
+++ b/sys/databases/pgsql_sql.php
@@ -27,5 +27,25 @@ class pgSQL_SQL extends DB_SQL {
 		return 'DROP TABLE "'.$name.'"';
 	}
 
+	/**
+	 * Limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limit
+	 * @param int $offset
+	 * @return string
+	 */
+	public function limit($sql, $limit, $offset=FALSE)
+	{
+		$sql .= " LIMIT {$limit}";
+
+		if(is_numeric($offset))
+		{
+			$sql .= " OFFSET {$offset}";
+		}
+
+		return $sql;
+	}
+
 }
 //End of pgsql_manip.php
\ No newline at end of file
diff --git a/sys/databases/sqlite_sql.php b/sys/databases/sqlite_sql.php
index e23fd99..c5165e0 100644
--- a/sys/databases/sqlite_sql.php
+++ b/sys/databases/sqlite_sql.php
@@ -86,17 +86,21 @@ class SQLite_SQL extends DB_SQL {
 	}
 
 	/**
-	 * Create an sqlite database file
-	 * 
-	 * @param  $path
+	 * Limit clause
+	 *
+	 * @param string $sql
+	 * @param int $limit
+	 * @param int $offset
+	 * @return string
 	 */
-	public function create_db($path)
+	public function limit($sql, $limit, $offset=FALSE)
 	{
-		// Create the file if it doesn't exist
-		if( ! file_exists($path))
+		if ( ! is_numeric($offset))
 		{
-			touch($path);
+			return $sql." LIMIT {$limit}";
 		}
+
+		return $sql." LIMIT {$offset}, {$limit}";
 	}
 }
 //End of sqlite_sql.php
\ No newline at end of file