Remove unique constriant from invoice_number column in suspended_sales

database/database.sql

@@ -583,8 +583,7 @@ CREATE TABLE `ospos_sales_suspended` (
   `sale_id` int(10) NOT NULL AUTO_INCREMENT,
   PRIMARY KEY (`sale_id`),
   KEY `customer_id` (`customer_id`),
-  KEY `employee_id` (`employee_id`),
-  UNIQUE KEY `invoice_number` (`invoice_number`)
+  KEY `employee_id` (`employee_id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8  ;
 
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