有没有办法在SQL查询中执行条件逻辑？

Question

So I have a fairly long complex query but the gist is that the query's basic functionality looks like this SELECT verification_id FROM verification_table

The verification_id returns an integer from 0-3. Is there a way to do something in the SQL query where if the verification_id is 0, it returns a string like "new" and different ones for all 4 verification_id's.

I can do this in the backend via PHP but i was wondering if there was a way to do it via MySQL

Answer 1

SELECT CASE 
         WHEN verification_id = 0 THEN 'new' 
         WHEN verification_id = 1 THEN 'something else' 
         ELSE 'error?' 
       END AS myvalue 
FROM   verification_table 

something like this should work.

Altough you may consider using the mysql ENUM field type which basically translates text strings into numbers and vice versa. It is an efficient field type of storing such values.