From 7a947c409ce8131ecd8949181830ec8fd94635ce Mon Sep 17 00:00:00 2001
From: Robson <robsonvnt@gmail.com>
Date: Mon, 16 Dec 2013 18:11:44 -0200
Subject: [PATCH 1/2] Was added foreign key support.

---
 classes/Drivers/Driver.php | 26 ++++++++++++++++++++++++++
 classes/Drivers/Mysql.php  | 12 ++++++++++++
 classes/Migration.php      | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+)

diff --git a/classes/Drivers/Driver.php b/classes/Drivers/Driver.php
index 0ea0561..6eab497 100644
--- a/classes/Drivers/Driver.php
+++ b/classes/Drivers/Driver.php
@@ -134,6 +134,32 @@ abstract public function change_column($table_name, $column_name, $params);
 	 */
 	abstract public function remove_column($table_name, $column_name);
 
+	/**
+	 * Add a foreign key to a table
+	 *
+	 * @example add_foreign_key ( "client", "city_id", "city", "id");
+	 *
+	 * @param   string  Name of the table
+	 * @param   string  Name of the column
+	 * @param   string  Name of referenced table
+	 * @param   string  Name of referenced column
+	 * @return  boll    Returns true if no errors
+	 */
+	abstract public function add_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name);
+
+	/**
+	 * Remove a foreign key from a table
+	 *
+	 * @example remove_foreign_key ( "client", "city_id", "city", "id");
+	 *
+	 * @param   string  Name of the table
+	 * @param   string  Name of the column
+	 * @param   string  Name of referenced table
+	 * @param   string  Name of referenced column
+	 * @return  boll    Returns true if no errors
+	 */
+	abstract public function remove_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name);
+
 	/**
 	 * Add an index
 	 *
diff --git a/classes/Drivers/Mysql.php b/classes/Drivers/Mysql.php
index 0f1d8a1..e6852cd 100644
--- a/classes/Drivers/Mysql.php
+++ b/classes/Drivers/Mysql.php
@@ -91,6 +91,18 @@ public function remove_column($table_name, $column_name)
 		return $this->run_query("ALTER TABLE $table_name DROP COLUMN $column_name ;");
 	}
 	
+	public function add_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name)
+	{
+		$fk = 'fk'.$table_name.$column_name.$referenced_table_name.$referenced_column_name;
+		return $this->run_query("ALTER TABLE $table_name ADD CONSTRAINT $fk "
+			."FOREIGN KEY ( `$column_name` ) REFERENCES `$referenced_table_name` ( `$referenced_column_name` ); ");
+	}
+	
+	public function remove_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name){
+		$fk = 'fk'.$table_name.$column_name.$referenced_table_name.$referenced_column_name;
+		return $this->run_query("ALTER TABLE $table_name DROP FOREIGN KEY $fk;");
+	}
+
 	public function add_index($table_name, $index_name, $columns, $index_type = 'normal')
 	{
 		switch ($index_type)
diff --git a/classes/Migration.php b/classes/Migration.php
index 4bc37e6..b6c6d10 100644
--- a/classes/Migration.php
+++ b/classes/Migration.php
@@ -199,6 +199,40 @@ public function remove_column($table_name, $column_name)
 		return $ret;
 	}
 
+	/**
+	 * Add a foreign key to a table
+	 *
+	 * @example add_foreign_key ( "client", "city_id", "city", "id");
+	 *
+	 * @param   string  Name of the table
+	 * @param   string  Name of the column
+	 * @param   string  Name of referenced table
+	 * @param   string  Name of referenced column
+	 * @return  boll    Returns true if no errors
+	 */
+	public function add_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name)
+	{
+		$ret = $this->driver->add_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name);
+		return $ret;
+	}
+
+	/**
+	 * Add a foreign key to a table
+	 *
+	 * @example remove_foreign_key ( "client", "city_id", "city", "id");
+	 *
+	 * @param   string  Name of the table
+	 * @param   string  Name of the column
+	 * @param   string  Name of referenced table
+	 * @param   string  Name of referenced column
+	 * @return  boll    Returns true if no errors
+	 */
+	public function remove_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name)
+	{
+		$ret = $this->driver->remove_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name);
+		return $ret;
+	}
+
 	/**
 	 * Add an index
 	 *

From 57cb8011e9f642805f516b1e422bac4401fe5863 Mon Sep 17 00:00:00 2001
From: Robson <robsonvnt@gmail.com>
Date: Mon, 16 Dec 2013 18:23:24 -0200
Subject: [PATCH 2/2] Doc

---
 README.markdown | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/README.markdown b/README.markdown
index 025d354..d2359cc 100644
--- a/README.markdown
+++ b/README.markdown
@@ -147,6 +147,9 @@ rename_column($table_name, $column_name, $new_column_name)
 change_column($table_name, $column_name, $params)
 remove_column($table_name, $column_name)
 
+add_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name)
+remove_foreign_key($table_name, $column_name, $referenced_table_name, $referenced_column_name)
+
 add_index($table_name, $index_name, $columns, $index_type = 'normal')
 remove_index($table_name, $index_name)
 ```