1. Hapus goods_stock yang goods_stock total_quantity_buy = 0
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2. Periksa dan perbaiki buy_seq_no yang ada goods_stock dan buy

   SELECT * FROM `goods_stock` group by `buy_seq_no`
   SELECT * FROM `buy` ORDER BY `buy_seq_no` 
   
  
   OMC: 
   buy_seq_no = 191
   		  678
   		  722
   		  732
   		  997
   
   SELECT * FROM `buy` WHERE 	`buy_seq_no` = '00191' or 
    				`buy_seq_no` = '00678' or 
    				`buy_seq_no` = '00722' or 
    				`buy_seq_no` = '00732' or 
    				`buy_seq_no` = '00997' 

   Hapus data tsb, tapi check dulu apakah ada buy_detail-nya. 
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3. Yakinkan harga buy_detail.unit_buy_price dan buy_detail.discount 
   untuk buy_detail.goods_code yang sama dalam buy.buy_seq_no
   tidak berbeda. Harus sama.
   
   Jalankan sql berikut:
   
   1.	   create temporary table temp (
	  	        buy_seq_no   		char(5),
			goods_code            	varchar(20),
			unit_buy_price  	double unsigned)
	   ;
	   
	   lock tables buy read, buy_detail read;
	   
	   insert into temp
	   select buy.buy_seq_no, buy_detail.goods_code, buy_detail.unit_buy_price
	   from buy_detail, buy 
	   where  buy.supplier_code 	= buy_detail.supplier_code and
		  buy.invoice_no 	= buy_detail.invoice_no
		  
	   group by buy.buy_seq_no, buy_detail.goods_code, buy_detail.unit_buy_price
	   ;
	   
	   
	   select buy_seq_no, goods_code, count(concat(buy_seq_no, goods_code)) as invalid 
	   from temp
	   group by buy_seq_no, goods_code
	   order by invalid desc
	   ;

   Untuk yang Field invalid > 1, buy_detail.unit_buy_price!!!!
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