Use the cursor (cursor)
1. Declare the cursor
DECLARE cursor_name CURSOR FOR select_statement
This statement declares a cursor. The cursor may be defined in a plurality of subroutines, but in a block cursor for each must have a unique name. After declaring a cursor is a single operation, but can not use a SELECT statement can not have INTO clause.
2. OPEN cursor statement
OPEN cursor_name
This statement opens a previously declared cursor.
3. cursor FETCH statement
FETCH cursor_name INTO var_name [, var_name] ...
This statement with the specified open cursor reads the next line (the next line if there is any), and advances the cursor pointer.
4. Cursor CLOSE statement
CLOSE cursor_name
The statement closes a previously opened cursor.
Check before you write a lot of information but not always executed, after pondering for a moment from, wrote example, tested entirely correct.
The following is a stored procedure to create, using the example of a cursor loop update operation:
CREATE PROCEDURE `my`()
BEGIN
/ * Local variables defined DECLARE * /
declare aid bigint default 0 ;
declare mdsl bigint default 0;
declare stop int default 0;
declare cur CURSOR FOR (select count(area_tb.id) as mdsl, area_tb.id as aid from area_tb right join subbranch_tb on subbranch_tb.i_subbran_area=area_tb.id
where area_tb.i_record_status=0 and subbranch_tb.i_record_status=0 group by area_tb.id);
declare CONTINUE HANDLER FOR SQLSTATE '02000' SET stop = null;
/ * Open the cursor * /
OPEN cur;
/ * Cursor to go one step down, two to check out the value paid two variables defined * /
FETCH cur INTO mdsl,aid;
/ * Loop that is clear of the cursor query the name will add up and use; separated number * /
WHILE ( stop is not null) DO
update area_tb set i_subbran_count=mdsl where id = aid ;
/ * Take a step down cursor * /
FETCH cur INTO mdsl,aid;
END WHILE;
CLOSE cur;
END;
Finally, do not forget: to connect to the database user granted permission to execute a stored procedure
grant execute on procedure yunzuche.myupdate to 'username' @ '%';
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