你如何在 MySQL select 语句中编写条件?

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时间:2020-08-31 14:23:23  来源:igfitidea点击:

How do you write a conditional in a MySQL select statement?

sqlmysql

提问by Langdon

I'm using MySQL, and I want to do a sort of ternary statement in my SQL like:

我正在使用 MySQL,并且我想在我的 SQL 中执行一种三元语句,例如:

SELECT USER_ID, ((USER_ID = 1) ? 1 : 0) AS FIRST_USER
  FROM USER

The results would be similar to:

结果将类似于:

USER_ID | FIRST_USER
1       | 1
2       | 0
3       | 0
etc.

How does one accomplish this?

如何做到这一点?

回答by x2.

SELECT USER_ID, (CASE USER_ID WHEN 1 THEN 1 ELSE 0 END) as FIRST_USER FROM USER

回答by Jason

SELECT USER_ID, IF(USER_ID = 1, 1, 0) AS FIRST_USER FROM USER

The IF()statement works similarly to the ternary ? : operator.

IF()语句的工作方式类似于三元?: 操作员。