left outer join issue in mysql

Question

I am try to get all the rows in parts_keywords not included in parts_questions. Unfortunately, I am getting all the rows of both tables.

SELECT *FROM parts_keywords 
    LEFT OUTER JOIN parts_questions ON parts_keywords.ID = parts_questions.question_id
     WHERE parts_questions.question_id IS NULL
     AND parts_keywords.term  LIKE '%where%' || parts_keywords.term LIKE '%how%' || parts_keywords.term LIKE '%who%' || parts_keywords.term LIKE '%what%' 
    ORDER BY parts_keywords.ID DESC lIMIT 15

I have tried using the OR instead of ||. I have also tried using MATCH instead of LIKE to no avail.

When i use only one LIKE element, such as 'who' i get the correct results. However, it is important for me to get result for all LIKE elements together.

Please help

Answer 1

Try using paranthesis

SELECT * FROM parts_keywords pk
LEFT OUTER JOIN parts_questions pq ON pk.ID = pq.question_id
WHERE pq.question_id IS NULL
AND ( pk.term LIKE '%where%' OR pk.term LIKE '%how%' OR pk.term LIKE '%who%' OR pk.term     LIKE '%what%' )
ORDER BY parts_keywords.ID DESC lIMIT 15