MySQL Unknown column in 'on clause' :( - php

Question

My query looks like
SELECT а.*, m.username, m.picture, m.picture_active
FROM questions_answer AS а
INNER JOIN members AS m ON а.poster_id=m.member_id
INNER JOIN questions AS q ON q.question_id=a.question_id
ORDER BY a.postdate DESC
I'm getting error:
Unknown column 'a.question_id' in 'on clause'
I don't know what is wrong, please help me with this.
Table questions is
CREATE TABLE IF NOT EXISTS `questions` (
`question_id` int(9) unsigned NOT NULL AUTO_INCREMENT,
`member_id` int(9) unsigned NOT NULL DEFAULT '0',
`question` text NOT NULL,
`postdate` int(10) unsigned NOT NULL DEFAULT '0',
`active` tinyint(1) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`question_id`),
KEY `member_id` (`member_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;
and questions_answer is
CREATE TABLE IF NOT EXISTS `questions_answer` (
`answer_id` bigint(12) unsigned NOT NULL AUTO_INCREMENT,
`question_id` int(9) unsigned NOT NULL,
`poster_id` int(9) unsigned NOT NULL,
`body` text NOT NULL,
`postdate` int(9) unsigned NOT NULL,
PRIMARY KEY (`answer_id`),
KEY `question_id` (`question_id`),
KEY `poster_id` (`poster_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

Answer 1

Your table questions_answer may not have the column question_id

Answer 2

It would seem you don't have a column a.question_id
Check your structure for that table.

Answer 3

There is not any column called question_id in the questions_answer table.

Answer 4

Funny thing, if I use this code, it works:
SELECT qa.*
FROM questions_answer qa
INNER JOIN questions q ON qa.question_id = q.question_id
ORDER BY qa.postdate DESC
SQL-fiddle
So, to apply this to your query:
SELECT qa.*, m.username, m.picture, m.picture_active
FROM questions_answer qa
INNER JOIN questions q ON qa.question_id = q.question_id
INNER JOIN members m ON qa.poster_id = m.member_id
ORDER BY qa.postdate DESC

Answer 5

Your questions_answer table alias a has some issues. It most probably isn't the letter a.
FROM questions_answer AS а
I was playing around with it and found an error once that noted Unknown table 'аa': As you can see, it might be a special character. A short search on net came up with letter Eth
I replaced the alias with character a and the query works fine.
SELECT a.*, m.username, m.picture, m.picture_active
FROM questions_answer AS a
INNER JOIN members AS m ON a.poster_id=m.member_id
INNER JOIN questions AS q ON q.question_id=a.question_id
ORDER BY a.postdate DESC
See example here Just copy paste your query there and try to run, it will complain because of alias character issue. You can even copy the alias from you line and replace all as with it, it will work as well.