Question

I need to create a MySQL query with an IF statement. Here is a database schema:

CREATE DATABASE my_db;
USE my_db;
CREATE TABLE IF NOT EXISTS if_table(
    id INTEGER unsigned,
    field_1 INTEGER unsigned,
    field_2 INTEGER unsigned,
    field_3 INTEGER unsigned,
    PRIMARY KEY (id)
);

How do I write an UPDATE query which corresponds to next pseudo code?

if field_2 equals 0 then field_1 = field_1 + 1
else field_3 = field_3 + 2 
where id == 1

Answer 1

Try this in-line IF statement

SELECT IF(field_2 = 0, field_1 + 1, field_3 + 2) AS `Result`
FROM tableName
WHERE ID = 1

or if you want to update the value,

UPDATE tableName
SET field_1 = IF(field_2 = 0, field_1 + 1, field_1),  
    field_3 = IF(field_2 = 0, field_3, field_3 + 2)
WHERE ID = 1