First of all apologies for if the syntax and framing of question isn't up to the standards.
I have a MySql database .I have a table answer which contains idquestion, userAnswer, userEmailAddress as columns.
Another table multi_choice_pool, which contains idQuestion, answer_all.
Every answer.userEmailAddress has multiple entries of idQuestion and userAnswer.
I want to obtain userEmailAddress in answer table where id and answer of that userEmailAddress equals the iq and answer of multi_choice_pool.
I wrote this:
Select answer.userEmailAddress from answer
where (answer.idQuestion=multi_choice_pool.idQuestion) AND
(answer.userAnswer=multi_choice_pool.answer_all);
Which is giving me an error: "Unknown column 'multi_choice_pool' in where clause.
Is the syntax wrong? Or the query is wrong itself? Or my approach isn't right? Can you rectify and provide suggestion?
Select answer.userEmailAddress
from answer left join multi_choice_pool
on answer.idQuestion = multi_choice_pool.idQuestion
and answer.userAnswer = multi_choice_pool.answer_all;
It seems you don't need the WHERE
clause.
But you need the JOIN
one :
SELECT answ.userEmailAddress
FROM answer answ
LEFT OUTER JOIN multi_choice_pool mcp
ON answ.idQuestion = mcp.idQuestion
AND answ.userAnswer = mcp.answer_all
Here is the MySQL documentation for JOIN .
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