Multiple IF statements on MYSQL

You need to nest the if statements

SELECT item_code, IF(category_code = 'HERR1', 'NO', IF(category_code = 'COLN5', 1, 2)) AS category_code, item_name, item_quantity FROM qa_items

Then the first if will fail and the nested if will evaluate

Try the following

SELECT item_code, CASE category_code WHEN 'HERR1' THEN 1 WHEN 'COLN5' THEN 0 ELSE 'NONE' END AS category_code, item_name, item_quantity FROM qa_items

I'd rather use CASE :

SELECT item_code, 
CASE category_code 
WHEN 'HERR1' THEN 1
WHEN 'COLN5' THEN 2
ELSE 'NO'
END as category_code, item_name, item_quantity 
FROM qa_items

But IF will also work : IF(category_code='HERR1',1, IF(category_code='COLN5',2,'NO'))

Is this what you were after?

SELECT
  item_code,
  CASE category_code
    WHEN 'HERR1' THEN 1
    WHEN 'COLN5' THEN 2
    ELSE 'NO'
  END AS category_code,
  item_name,
  item_quantity
FROM qa_items