Case when then, but with AND condition inside when and before then

Question

In the below query I want to add an AND condition inside the CASE\'s WHEN and before THEN is that possible?

for example WHEN \'r\' AND table1.name=\"jones\" THEN \'very

Answer 1

Anything that evaluates to a boolean (true or false) can go in the WHEN condition of a CASE statement. So you can replace 'r' with:

('r' AND table1.name='jones')

Thinking about this more, you might have to lose the table1.event after CASE

SELECT table1.id, table1.name,
    CASE 
        WHEN (table1.event = 'r' AND table1.name='Jones') THEN 'very high'
        WHEN table1.event = 't' THEN 'very low'
        ELSE (SELECT table2.risk 
              FROM table2 
              WHERE table2.value <= table1.value 
              ORDER BY table2.value DESC LIMIT 1)
    END AS risk
FROM table1
ORDER BY FIELD( table1.event, 'r', 'f', 't' ), table1.value DESC

Answer 2

You can rewrite your statement like this to accomplish what you want

SELECT table1.id, table1.name,
   CASE 
     WHEN table1.event = 'r' AND table1.name = 'jones' THEN 'very high'
     WHEN table1.event = 't' AND table1.name = 'smith' THEN 'very low'
     ELSE (SELECT table2.risk FROM table2 WHERE table2.value <= table1.value
           ORDER BY table2.value DESC LIMIT 1)
   END AS risk
FROM table1
ORDER BY FIELD( table1.event, 'r', 'f', 't' ), table1.value DESC

notice that you need to remove table1.event after the CASE statement. documentation here

Answer 3

Switch from case <column> when <value> then ... to case when <condition> then ...:

CASE 
WHEN table1.event = 'r' AND table1.active = 1 THEN 'very high'
...