Introduction to the DB2 cursor Loop

This article mainly introduces how to use an instance to explain the problem of DB2 cursor loop. If you are curious about using an instance to explain the problem of DB2 cursor loop, the following articles will unveil its secrets. The following is a detailed description of the article. I hope you can learn from it.

The stored procedure example in this article shows that the expected number of cycles is the number of rows in the yh table. Because select iid into pint from yh where 0 = 1; No rows are returned, so after at_end, it will immediately be equal to 1 (only one loop will exit ).

 
 

  
  
DECLARE　at_end　INT　DEFAULT　0;   
  
  
DECLARE PIID INTEGER DEFAULT 0 ;   
  
  
DECLARE PINT INTEGER DEFAULT 0 ;   
  
  
DECLARE　not_found　CONDITION　FOR　SQLSTATE　'02000';   
  
  
--DECLARE PCOUNT INTEGER;   
  
  
DECLARE　c1　CURSOR　FOR   
  
  
SELECT IID FROM YH;   
  
  
DECLARE　CONTINUE　HANDLER　FOR　not_found   
  
  
SET　at_end　=　1;   
  
  
OPEN　c1;   
  
  
SET PCOUNT=0;   
  
  
ins_loop:   
  
  
LOOP   
  
  
FETCH　c1　INTO　PIID;   
  
  
IF　at_end　<>0THEN   
  
  
LEAVE　ins_loop;   
  
  
END　IF;   
  
  
SET PCOUNTPCOUNT=PCOUNT+1;   
  
  
SELECT IID INTO PINT FROM YH WHERE 0=1;   
  
  
END LOOP; 
 
 

The above content is an introduction to the problem of DB2 cursor loop with an instance. I hope you will gain some benefits.

The above content describes how to use an instance to explain the problem of DB2 cursor loop. I hope it will help you in this regard.