SQL语句1 = 1 [英] SQL Statement 1=1

问题描述

谁能告诉我该条件的用途是什么
1 = 1在WHERE子句中?
在此先感谢

Hi,
Can anyone tell me what is the use of the condition
1=1 in WHERE Clause?
Thanks in advance

推荐答案

可以只是实词句的占位符，例如"if(true){/* ... */}"

Could be just a placeholder for real clause, like "if (true) {/* ... */}"

auauahua可能无需测试就使用参数，是否追加了"WHERE"子句，我在很多系统中都看到了该子句，其中开发人员仅将其用于追加"AND"子句.
SELECT NAME WHERE 1 = 1
AND FILTER1 ="BLA BLA BLA"
AND FILTER2 ="AGA AGA AG"
...

X |

auauahua maybe use the parameters without test if append "WHERE" clause or not, i saw in a lot of systems this clause where developers use only for append the clause "AND"

SELECT NAME WHERE 1=1
AND FILTER1="BLA BLA BLA"
AND FILTER2 ="AGA AGA AG"
...

X|

应该提高其他人没有任何条件的SQL查询的性能.它还允许您构建动态查询，因为在查询末尾使用WHERE 1=1，您需要添加的只是用于您实际情况的AND子句.

It''s supposed to increase performance on a SQL query that otherwsie doesn''t have any conditions. It also allows you to build dynamic queries because with the WHERE 1=1 at the end of your query, all you have to add is AND clauses for your actual conditions.

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