mysql - 是否可以根据某些条件选择特定值？

Question

我想知道是否可以根据给定行是否匹配某些条件从 myTable 中选择“真”或“假”。因此，例如，如果用户在名为 phone_number 的列中有或没有值，我会这样做......

select (**some magic here**) as has_phone_number from users;

结果将是一堆“真”或“假”

TIA。

score 2 · Accepted Answer

IF (phone_number != '', true, false) as has_phone_number

甚至

phone_number != '' as has_phone_number

score 2 · Accepted Answer

使用案例陈述。

SELECT CASE WHEN Phone IS NULL THEN FALSE ELSE TRUE END AS has_phone_number FROM users;

score 0 · Accepted Answer

0

select
  phone = '' as has_phone_number
from users

于 2012-11-02T23:19:58.587 回答

3 回答 3