第一次用ＭＹＳＱＬ，这条插入语句怎么写？

[xiaoqhuang]

if not exists (select 1 from account where username='123') insert into account (username,passwd) values('123','123')

[willko]

如果表account的字段username没有值为123的数据,就插入一个username为123 passwd为123

[studenthj]

同意楼上说的

[xiaoqhuang]

晕啊，楼上的兄弟，意思我当然知道了，我问题是这条语句在ＭＹＳＱＬ里面怎么写。
我这样的写法在ms sql 2000里行得通，到ＭＹＳＱＬ里就报错了

[仰望星空WU]

INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE]
[INTO] tbl_name [(col_name,...)]
SELECT ...
[ ON DUPLICATE KEY UPDATE col_name=expr, ... ]

[懒得去死]

执行:
call sp_guests();

[懒得去死]

DELIMITER $$;

DROP PROCEDURE IF EXISTS sp_test$$

CREATE PROCEDURE sp_test()
BEGIN
declare cnt int;
select 1 from account where username='123' into cnt;
if cnt != 0 then
insert into account (username,passwd) values('123','123');
end if;
END$$

DELIMITER ;$$

[懒得去死]

DELIMITER $$;

DROP PROCEDURE IF EXISTS `emushu`.`sp_guests`$$

CREATE PROCEDURE sp_test()
BEGIN
declare cnt int;
select 1 from account where username='123' into cnt;
if cnt != 0 then
insert into account (username,passwd) values('123','123');
end if;
END$$

DELIMITER ;$$