-- Place your SQL code here
UPDATE vn.claimLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.itemLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.entryLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.supplierLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.zoneLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.travelLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.routeLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.clientLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert';
UPDATE vn.shelvingLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert';
UPDATE vn.ticketLog
        SET oldInstance = NULL
    WHERE `action` = 'insert';
UPDATE vn.deviceProductionLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert'; 
UPDATE vn.workerLog  
        SET oldInstance = NULL
    WHERE `action` = 'insert';