IF... ELSE in WHERE clause MySQL

if-statement, mysql

Solution

The syntax for `IF` is :

 IF(test_expr, then_expr, else_expr)

so you could do something like `IF(test1, result1, IF(test2, result2, else_result))` but it would not be very readable, so there's the `CASE` expression for that purpose.

CASE WHEN  test1 THEN result1
WHEN test2 THEN result2
ELSE else_result END

If you want to condition a select column, you can use the `IF` in the select fields directly:

SELECT IF(match, nl_column en_column) AS lang 
FROM table

Note that an expression in a where clause is either `TRUE` or `FALSE`, so writing

IF(expr, TRUE, FALSE)

is the same as

expr

Problem

I'm trying to use a IF...ELSE function in a MySQL WHERE statement without success. I have this query: ``` SELECT id FROM mytable WHERE restrcountry NOT LIKE '%*nl*%' AND (IF languages LIKE '%*nl*%', 1, 0) = 1; ``` Ok, this is my query with IF statement. However, how can I use also "ELSE"? Example, I would like to do something similar: IF language match nl ---> select id field where language is nl ELSE IF language NOT match nl ---> select id field where language is en How can I do this in a MySQL query, please? Thanks to all!

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