如题,现在一直通过mysql_affected_rows()在判断,这样的话就造成几乎每一句update,delete,insert后面必然要跟一句
if(mysql_affected_rows()!=1)
{
报错
}
请问有什么更简便的办法吗?
回复讨论(解决方案)
mysql_affected_rows 不是用于检查执行是否成功的
而是用于观察相关 sql 指令对多少记录进行了操作
直接
if(执行sql语句){.....}else{......}
mysql_affected_rows 不是用于检查执行是否成功的
而是用于观察相关 sql 指令对多少记录进行了操作
是我表述问题。我就是想判断insert,delete,update语句成功地影响了至少1行
判断影响了几行mysql_affected_rows() 肯定是要执行的。
无论影响多少行(包括0行)都不是错误
无论影响多少行(包括0行)都不是错误
这我当然知道。。。
如题,现在一直通过mysql_affected_rows()在判断,这样的话就造成几乎每一句update,delete,insert后面必然要跟一句
if(mysql_affected_rows()!=1)
{
报错
}
请问有什么更简便的办法吗?
补充一下,我是要判断update,delete,insert语句至少影响了1行,似乎大部分情况下都需要这样的判断逻辑
就是因为即使update,delete,insert影响了0行,事务也不会回滚,所以会产生这个问题
update 没有符合条件的记录,就不会修改,如果被修改的值和原值一样,则修改不会真正发生
delete 没有符合条件的记录,就不会删除,如果有多条符合条件的记录,自然也就一并删除了
insert 只会影响一条,哪怕是用缩略写法的 insert 语句插入了 100 条
看不出这与事务有什么关系
update 没有符合条件的记录,就不会修改,如果被修改的值和原值一样,则修改不会真正发生
delete 没有符合条件的记录,就不会删除,如果有多条符合条件的记录,自然也就一并删除了
insert 只会影响一条,哪怕是用缩略写法的 insert 语句插入了 100 条
看不出这与事务有什么关系
想了一下,你说的有道理。
我把我的疑问举个例子:
比如用户要用虚拟货币购买虚拟物品,在update ... set money= ... where user_id=... 这条语句执行后,需不需要mysql_affected_rows()来验证成功update了1行呢?我担心没真正update到money字段,然后就执行了下面给该用户添加虚拟物品的业务
如果在之前执行了select money from ... for update,就能保证万无一失吗?
update 没有符合条件的记录,就不会修改,如果被修改的值和原值一样,则修改不会真正发生
delete 没有符合条件的记录,就不会删除,如果有多条符合条件的记录,自然也就一并删除了
insert 只会影响一条,哪怕是用缩略写法的 insert 语句插入了 100 条
看不出这与事务有什么关系
想了一下,你说的有道理。
我把我的疑问举个例子:
比如用户要用虚拟货币购买虚拟物品,在update ... set money= ... where user_id=... 这条语句执行后,需不需要mysql_affected_rows()来验证成功update了1行呢?我担心没真正update到money字段,然后就执行了下面给该用户添加虚拟物品的业务
如果在之前执行了select money from ... for update,就能保证万无一失吗?
直接if (update操作....){购买成功...}else{购买失败....}不就好了,update操作失败返回的是false
$result = mysql_query("update ……")if ($result !== false){ echo "exec success";}else{ echo "exec error:".mysql_error():}
update 没有符合条件的记录,就不会修改,如果被修改的值和原值一样,则修改不会真正发生
delete 没有符合条件的记录,就不会删除,如果有多条符合条件的记录,自然也就一并删除了
insert 只会影响一条,哪怕是用缩略写法的 insert 语句插入了 100 条
看不出这与事务有什么关系
想了一下,你说的有道理。
我把我的疑问举个例子:
比如用户要用虚拟货币购买虚拟物品,在update ... set money= ... where user_id=... 这条语句执行后,需不需要mysql_affected_rows()来验证成功update了1行呢?我担心没真正update到money字段,然后就执行了下面给该用户添加虚拟物品的业务
如果在之前执行了select money from ... for update,就能保证万无一失吗?
直接if (update操作....){购买成功...}else{购买失败....}不就好了,update操作失败返回的是false
好的我决定试一下,看起来比mysql_affected_rows简洁,不知道效果上有没有什么细微差别
$result = mysql_query("update ……")if ($result !== false){ echo "exec success";}else{ echo "exec error:".mysql_error():}
同上,谢谢,准备试一下效果
如果你不放心 update ... set money=money-1 会真实执行的话
那么你是否需要再 select 一下,确认 money 减少了 1,而不是减少了 100 呢?
$result = mysql_query("update ……")
只有在 sql 指令是错误的情况下,才会返回 false
所以并不需要去试
如果你不放心 update ... set money=money-1 会真实执行的话
那么你是否需要再 select 一下,确认 money 减少了 1,而不是减少了 100 呢?
$result = mysql_query("update ……")
只有在 sql 指令是错误的情况下,才会返回 false
所以并不需要去试
如果你不放心 update ... set money=money-1 会真实执行的话
那么你是否需要再 select 一下,确认 money 减少了 1,而不是减少了 100 呢?
$result = mysql_query("update ……")
只有在 sql 指令是错误的情况下,才会返回 false
所以并不需要去试
好的,感觉你说的听起来比较靠谱,谢谢。

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