Can anyone tell me how to do a FULL OUTER JOIN in mySQL
Posted: Wed Mar 10, 2004 4:27 am
Hi there guys, I'm having a problem with a mySQL query. the dbs are as follows:
answer_value(id, answer_id)
user_answers(user_id, answer_value_id, answer_text)
I need to join the tables on answer_value.id = user_answers.answer_value_id and need to pull out every answer_value.id for a specific user_answers.user_id and need to be able to recognise where no answer_text occurs.
(the user_answers.answer_value_id's will be a subset of the answer_value.id's).
So far I have:
SELECT answer_value.id, user_answers.answer_value_id, user_answers.answer_text FROM answer_value LEFT JOIN (SELECT * FROM user_answers WHERE user_id = $userid) AS uav ON answer_value.id = user_answers.answer_value_id
But, of course it errors.
Thanks in advance for the help. It would be grately appreciated and I'm so tired...
answer_value(id, answer_id)
user_answers(user_id, answer_value_id, answer_text)
I need to join the tables on answer_value.id = user_answers.answer_value_id and need to pull out every answer_value.id for a specific user_answers.user_id and need to be able to recognise where no answer_text occurs.
(the user_answers.answer_value_id's will be a subset of the answer_value.id's).
So far I have:
SELECT answer_value.id, user_answers.answer_value_id, user_answers.answer_text FROM answer_value LEFT JOIN (SELECT * FROM user_answers WHERE user_id = $userid) AS uav ON answer_value.id = user_answers.answer_value_id
But, of course it errors.
Thanks in advance for the help. It would be grately appreciated and I'm so tired...