爲什麼在MySQL中_特別？

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) 

爲什麼我需要逃脫_？

Answer 1

因爲_和%都是LIKE的特殊字符。

_匹配一個字符，%任意數量的字符。

Answer 2

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

你可以得到更多的從這些鏈接：

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