所以我想做的是为体育应用程序(特别是足球)构建一个 Web 应用程序。现在,我在使用应该在记录比赛得分后更新排名的触发器时遇到了问题。在这个例子中,我有一个“游戏”表和一个“排名”表,就像这样。
mysql> describe game;
+-----------------+------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+------------+------+-----+---------+-------+
| sid | int(11) | NO | PRI | NULL | |
| fid | int(11) | NO | PRI | NULL | |
| lid | int(11) | NO | PRI | NULL | |
| htid | int(11) | NO | PRI | NULL | |
| atid | int(11) | NO | PRI | NULL | |
| date | date | NO | | NULL | |
| time | time | NO | | NULL | |
| h_g | int(11) | NO | | 0 | |
| a_g | int(11) | NO | | 0 | |
| has_been_played | tinyint(1) | NO | | 0 | |
+-----------------+------------+------+-----+---------+-------+
10 rows in set (0.00 sec)
mysql> describe standings;
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| tid | int(11) | NO | PRI | NULL | |
| sid | int(11) | NO | PRI | NULL | |
| lid | int(11) | NO | PRI | NULL | |
| pld | int(11) | NO | | 0 | |
| pts | int(11) | NO | | 0 | |
| h_w | int(11) | NO | | 0 | |
| h_t | int(11) | NO | | 0 | |
| h_l | int(11) | NO | | 0 | |
| h_gf | int(11) | NO | | 0 | |
| h_ga | int(11) | NO | | 0 | |
| a_w | int(11) | NO | | 0 | |
| a_t | int(11) | NO | | 0 | |
| a_l | int(11) | NO | | 0 | |
| a_gf | int(11) | NO | | 0 | |
| a_ga | int(11) | NO | | 0 | |
+-------+---------+------+-----+---------+-------+
15 rows in set (0.00 sec)
其中 h/atid(和 tid)、fid、sid 和 lid 分别是 team、field、season 和 league 表的外键。
我想在游戏更新后创建触发器。我在这个应用程序中的当前设计目标是,当插入“游戏”时,它还没有被“玩过”,当它被更新时,分数被记录下来,然后游戏被认为是“玩过”。所以这里是触发器的一部分:
CREATE TRIGGER `update_standing` AFTER UPDATE ON `game`
FOR EACH ROW
BEGIN
# If a score has been recorded already, we'll reverse the old score
# before updating the new score.
IF OLD.has_been_played THEN
# The Home Team previously recorded a win
IF OLD.h_g > OLD.a_g THEN
# Home win
UPDATE standings
SET pld = pld - 1,
h_w = h_w - 1,
pts = pts - 3,
h_gf = h_gf - OLD.h_g,
h_ga = h_ga - OLD.a_g
WHERE tid = OLD.htid
AND sid = OLD.sid
AND lid = OLD.lid;
# Away loss
UPDATE standings
SET pld = pld - 1,
a_l = a_l - 1,
a_gf = a_gf - OLD.a_g,
a_ga = a_ga - OLD.h_g
WHERE tid = OLD.atid
AND sid = OLD.sid
AND lid = OLD.lid;
ENDIF;
ENDIF;
END;
出于某种原因,我遇到了这些错误,但我不确定原因。
mysql> source new_trigger_myfam.sql
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 18
ERROR 1054 (42S22): Unknown column 'OLD.atid' in 'where clause'
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ENDIF' at line 1
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ENDIF' at line 1
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'END' at line 1
我的语法有明显错误吗?我知道我可以使用 case/when/then 在一个中执行两个更新查询。本质上,在触发器的这个片段中,我正在反转之前的更新,然后有更多的代码实际上使更新的其余部分发生。我对触发器还很陌生,因此我们非常感谢您的帮助。
最佳答案
根据 the documentation ,MySQL中的IF block 结束符是两个字:END IF
。
关于mysql - 触发错误 1054 (42S22),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19310703/