为什么_在MySQL中特殊？

Question

mysql> select 'ab' like 'a_%';
+-----------------+
| 'ab' like 'a_%' |
+-----------------+
|               1 |
+-----------------+
1 row in set (0.00 sec)

mysql> select 'ab' like 'a\_%';
+------------------+
| 'ab' like 'a\_%' |
+------------------+
|                0 |
+------------------+
1 row in set (0.00 sec)

mysql> select 'a_b' like 'a\_%';
+-------------------+
| 'a_b' like 'a\_%' |
+-------------------+
|                 1 |
+-------------------+
1 row in set (0.00 sec)

为什么我需要转义_？

Answer 1

因为_和%都是LIKE的特殊字符。

_匹配一个字符，%任意数量的字符。

Answer 2

"_" means underscore. I think "_" used for hiding any character under it. It is special because we can place character for it.

您可以从以下链接获取更多信息：

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