MYSQL - 使用while循环更新

Question

declare c int 
set c = 1 
while c<700 do 
update users set profile_display_name = concat(substring(first_name,1,1), last_name) 
     where profile_display_name is null and id between ((c-1)*10000+1) and (c*10000); 
SET c = c+1; 
End while ; 

我得到错误。近声明时结束声明。我在哪里犯错？

Answer 1

这个作品多为我

更好

DELIMITER $$ 

CREATE DEFINER=`ops`@`localhost` PROCEDURE `myproc`() 
BEGIN 
DECLARE c INT; 
SET c = 1; 
WHILE c < 700 DO 
SELECT CONCAT('Loop #:', c) ; 

update users 
set profile_display_name = concat(substring(first_name,1,1), last_name) 
where (profile_display_name is null or profile_display_name = '') 
and id between ((c-1)*10000+1) and (c*10000); 

commit; 

SET c=c+1; 

END WHILE; 
END 

Answer 2

在MySQL复合语句和流程控制结构只能在存储程序中使用 - MySQL Compound-Statement Syntax

Answer 3

下面是它是如何被定义为一个存储过程：

DELIMITER $$ 
CREATE PROCEDURE proc_name() 
BEGIN 

    DECLARE c int ;      --- added ; 
    SET c = 1 ;       --- added ; 
    WHILE c<700 DO 
     UPDATE users 
     SET profile_display_name = concat(substring(first_name,1,1), last_name) 
     WHERE profile_display_name IS NULL 
      AND id BETWEEN ((c-1)*10000+1) AND (c*10000); 
     SET c = c + 1 ; 
    END WHILE ; 

END $$ 
DELIMITER ;