Adding an addPrimaryKey command to yii's db migrations -- supports composite primary keys

CDbCommand.php

/**
	 * Builds a SQL statement for creating a primary key constraint.
	 * @param string $name the name of the primary key to be created. The name will be properly quoted by the method.
	 * @param string $table the table who will be inheriting the primary key. The name will be properly quoted by the method.
	 * @param string $column the column where the primary key will be effected. The name will be properly quoted by the method.
	 * @return integer number of rows affected by the execution.
	 * @since 1.1.6
	 */
	public function addPrimaryKey($name,$table,$columns)
	{
		return $this->setText($this->getConnection()->getSchema()->addPrimaryKey($name,$table,$columns))->execute();
	}

	/**
	 * Builds a SQL statement for dropping a primary key constraint.
	 * @param string $name the name of the primary key to be dropped. The name will be properly quoted by the method.
	 * @param string $table the table that owns the primary key. The name will be properly quoted by the method.
	 * @return integer number of rows affected by the execution.
	 * @since 1.1.6
	 */
	public function dropPrimaryKey($name,$table)
	{
		return $this->setText($this->getConnection()->getSchema()->dropPrimaryKey($name,$table))->execute();
	}

CDbMigration.php

/*
	 *	Modifies exisiting column to become PK  -- for composite PK's
	 *  @param string $name name of the constraint to add
	 *	@param string $table name of the table to add primary key to
	 *  @param string $columns name of the column to utilise as primary key. If there are multiple columns, separate them with commas.
	 */
	public function addPrimaryKey($name,$table,$columns)
	{
		echo "    > alter table $table add constraint $name primary key ($columns) ...";
		$time=microtime(true);
		$this->getDbConnection()->createCommand()->addPrimaryKey($name,$table,$columns);
		echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
	}

	/*
	 *	Modifies exisiting column to become PK  -- for composite PK's
	 *  @param string $name name of the constraint to add
	 *	@param string $table name of the table to add primary key to
	 *  @param string $column name of the column to utilise as primary key. 
	 */
	public function dropPrimaryKey($name,$table)
	{
		echo "    > alter table $table drop constraint $name primary key $column ...";
		$time=microtime(true);
		$this->getDbConnection()->createCommand()->dropPrimaryKey($name,$table);
		echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
	}

CDbScehma.php

/**
	 * Builds a SQL statement for adding a primary key constraint to an existing table.
	 * The method will properly quote the table and column names.
	 * @param string $name the name of the primary key constraint.
	 * @param string $table the table that the primary key constraint will be added to.
	 * @param string $columns the name of the column to that the constraint will be added on.
	 * @return string the SQL statement for adding a primary key constraint to an existing table.
	 * @since 1.1.6
	 */
	public function addPrimaryKey($name,$table,$columns)
	{
		$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
		foreach($columns as $i=>$col)
			$columns[$i]=$this->quoteColumnName($col);
		return 'ALTER TABLE ' . $this->quoteTableName($table) . ' ADD CONSTRAINT '
			. $this->quoteColumnName($name) . '  PRIMARY KEY ('
			. implode(', ', $columns). ' )';
	}


	
	/**
     * Builds a SQL statement for removing a primary key constraint to an existing table.
     * The method will properly quote the table and column names.
     * @param string $name the name of the primary key constraint to be removed.
     * @param string $table the table that the primary key constraint will be removed from.
     * @return string the SQL statement for adding a primary key constraint to an existing table.
     * @since 1.1.6
     */
    public function dropPrimaryKey($name,$table)
    {
            return 'ALTER TABLE ' . $this->quoteTableName($table) . ' DROP CONSTRAINT '
                    . $this->quoteColumnName($name);
    }

customMigration.php

<?php

class m120619_234658_add_composite_pk extends CDbMigration
{
	public function up()
	{
		$this->addPrimaryKey('PK_FOO','tbl_fooBar','fooId, barId');


	}

	public function down()
	{
		$this->dropPrimaryKey('PK_FOO','tbl_fooBar');


	}

	
}