Question

I have two queries.

The first one is..

INSERT INTO balik 
    ( balik_date, 
      balik_time, 
      balik_cardID, 
      balik_status,
      balik_type )
   select 
         current_date(), 
         '00:00:00', 
         L_CardID, 
         'BELUM BALIK', 
         L_Type 
      FROM 
         logdetail t1  
            LEFT JOIN balik t2 
               ON t1.L_CardID = t2.balik_cardID
      WHERE 
             t1.L_Type = 'IN'   
         and t1.L_Date = current_date() 
         AND t2.balik_cardID IS NULL"

and another one is..

UPDATE balik blk  
   INNER JOIN logdetail ld  
      ON blk.balik_cardID = ld.L_CardID 
     and blk.balik_date = current_date()
   SET 
      blk.balik_status = 'SUDAH BALIK', 
      blk.balik_type = 'OUT',
      blk.balik_time = ld.L_Time  
   WHERE 
          ld.L_Type = 'OUT' 
      and ld.L_Date = current_date()

My problem is that when I execute the first and second query nothing happens unless I delete all records in my table beforehand. In that case both queries are executed and work like a charm.

Why is this happening?

Answer 1

From what I remember, you can’t do an insert into a table that is a result of a query that may be an impact of what you are inserting… So, it MIGHT help if the select was “wrapped” inside another layer so the inner query is completely processed FIRST and thus not impacted by the inserts.

INSERT INTO balik 
    ( balik_date, 
      balik_time, 
      balik_cardID, 
      balik_status,
      balik_type )
   select 
         PreQuery.newDate,
         PreQuery.newTime,
         PreQuery.newCardID,
         PreQuery.newStatus,
         PreQuery.newType
      from
         ( select 
                 current_date() newDate, 
                 '00:00:00'     newTime, 
                 L_CardID       newCardID, 
                 'BELUM BALIK'  newStatus, 
                 L_Type         newType
              FROM 
                 logdetail t1  
                    LEFT JOIN balik t2 
                       ON t1.L_CardID = t2.balik_cardID
              WHERE 
                     t1.L_Type = 'IN'   
                 and t1.L_Date = current_date() 
                 AND t2.balik_cardID IS NULL" ) PreQuery

I would alter the syntax on the update to more closely match that of the SQL Syntax per documentation… list the tables comma separated, then apply join conditions in the WHERE clause

UPDATE balik blk, logdetail ld  
   SET 
      blk.balik_status = 'SUDAH BALIK', 
      blk.balik_type = 'OUT',
      blk.balik_time = ld.L_Time  
   WHERE 
         blk.balik_cardID = ld.L_CardID 
     and blk.balik_date = current_date()
     and ld.L_Type = 'OUT' 
     and ld.L_Date = current_date()

Yeah, essentially the same thing, but might be interpretation issues.