Case-when usage in Mysql

In a SELECT statement query, you can make a judgment that is similar to if else by using case when to query the results.

The specific usage

1.

SELECT a.website_id, B.customer_name, A.website_enddate, C.member_name, d.websitetype_id,
Case
When D.websitetype_id=1 then 400
When d.websitetype_id=2 then 400
When d.websitetype_id=12 then 5800
When d.websitetype_id=13 then 5800
When d.websitetype_id=13 then 5800
END as Money

From ...

2.

SELECT a.website_id, B.customer_name, A.website_enddate, C.member_name, d.websitetype_id,
Case d.websitetype_id

When 1 then 400
When 2 then 400
When 5800
When 5800
When 5800
END as Money

From ...

3. A simple if judgment

The IF (Judgment statement, true return value, False value returned) uses the same location as the case-when position, the syntax is simple, a bit like the ternary operation in PHP.