ALTER TABLE `0_sales_orders` ADD COLUMN `reference` varchar(100) NOT NULL DEFAULT '' AFTER `branch_code`;
ALTER TABLE `0_sales_orders` DROP PRIMARY KEY;
ALTER TABLE `0_sales_orders` ADD PRIMARY KEY ( `trans_type` , `order_no` );
ALTER TABLE `0_sales_orders` ADD COLUMN `reference` varchar(100) NOT NULL DEFAULT '' AFTER `branch_code`;
ALTER TABLE `0_sales_orders` DROP PRIMARY KEY;
ALTER TABLE `0_sales_orders` ADD PRIMARY KEY ( `trans_type` , `order_no` );