如何消除SQL中的重复计算？(How to eliminate duplicate calculation in SQL?)

如何消除SQL中的重复计算？(How to eliminate duplicate calculation in SQL?)

我有一个可以简化为的SQL：

SELECT * FROM table WHERE LOCATE( column, :keyword ) > 0 ORDER BY LOCATE( column, :keyword )

您可以看到“LOCATE（column，：keyword）”的副本。 有没有办法只计算一次？

I have a SQL that can be simplified to:

SELECT * FROM table WHERE LOCATE( column, :keyword ) > 0 ORDER BY LOCATE( column, :keyword )

You can see there is a duplicate of "LOCATE( column, :keyword )". Is there a way to calculate it only once ?

最满意答案

HAVING在MySQL中使用别名：

SELECT *, LOCATE( column, :keyword ) AS somelabel FROM table HAVING somelabel > 0 ORDER BY somelabel

HAVING works with aliases in MySQL:

SELECT *, LOCATE( column, :keyword ) AS somelabel FROM table HAVING somelabel > 0 ORDER BY somelabel