select a column with a condition

I need to know if there is a way to work with conditions on colums...
e.g. how can I take the sum of all "answer" columns? Or how can I
select the score of e.g. only question7 (in combination with a query on
a question-table?)

Don't ask about the table structure... I didn't design it, and it's not
possible to change it...

CREATE TABLE `answer` (
`individualId` int(11) NOT NULL default '0',
`testId` int(11) NOT NULL default '0',
`question1` decimal(3,2) NOT NULL default '0.00',
`question2` decimal(3,2) NOT NULL default '0.00',
`question3` decimal(3,2) NOT NULL default '0.00',
`question4` decimal(3,2) NOT NULL default '0.00',
`question5` decimal(3,2) NOT NULL default '0.00',
`question6` decimal(3,2) NOT NULL default '0.00',
`question7` decimal(3,2) NOT NULL default '0.00',
`question8` decimal(3,2) NOT NULL default '0.00',
`question9` decimal(3,2) NOT NULL default '0.00',
PRIMARY KEY (`individualId`,`testId`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

Thanks!

gehegeradeaus@gmail.com wrote:

> I need to know if there is a way to work with conditions on colums...
> e.g. how can I take the sum of all "answer" columns? Or how can I
> select the score of e.g. only question7 (in combination with a query on
> a question-table?)
>
> Don't ask about the table structure... I didn't design it, and it's not
> possible to change it...
>
> CREATE TABLE `answer` (
> `individualId` int(11) NOT NULL default '0',
> `testId` int(11) NOT NULL default '0',
> `question1` decimal(3,2) NOT NULL default '0.00',
> `question2` decimal(3,2) NOT NULL default '0.00',
> `question3` decimal(3,2) NOT NULL default '0.00',
> `question4` decimal(3,2) NOT NULL default '0.00',
> `question5` decimal(3,2) NOT NULL default '0.00',
> `question6` decimal(3,2) NOT NULL default '0.00',
> `question7` decimal(3,2) NOT NULL default '0.00',
> `question8` decimal(3,2) NOT NULL default '0.00',
> `question9` decimal(3,2) NOT NULL default '0.00',
> PRIMARY KEY (`individualId`,`testId`)
> ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
>
> Thanks!

SELECT question1+question2... FROM answer ORDER BY individualId ?
SELECT sum(question7) FROM table WHERE...

strawberry schreef:

> gehegeradeaus@gmail.com wrote:
>
> > I need to know if there is a way to work with conditions on colums...
> > e.g. how can I take the sum of all "answer" columns? Or how can I
> > select the score of e.g. only question7 (in combination with a query on
> > a question-table?)
> >
> > Don't ask about the table structure... I didn't design it, and it's not
> > possible to change it...
> >
> > CREATE TABLE `answer` (
> > `individualId` int(11) NOT NULL default '0',
> > `testId` int(11) NOT NULL default '0',
> > `question1` decimal(3,2) NOT NULL default '0.00',
> > `question2` decimal(3,2) NOT NULL default '0.00',
> > `question3` decimal(3,2) NOT NULL default '0.00',
> > `question4` decimal(3,2) NOT NULL default '0.00',
> > `question5` decimal(3,2) NOT NULL default '0.00',
> > `question6` decimal(3,2) NOT NULL default '0.00',
> > `question7` decimal(3,2) NOT NULL default '0.00',
> > `question8` decimal(3,2) NOT NULL default '0.00',
> > `question9` decimal(3,2) NOT NULL default '0.00',
> > PRIMARY KEY (`individualId`,`testId`)
> > ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
> >
> > Thanks!
>
> SELECT question1+question2... FROM answer ORDER BY individualId ?
> SELECT sum(question7) FROM table WHERE...

Thanks for your answer, but that's not exactly what I'm searching for :

I need this :

SELECT question.questionId, individual.indivudal,
EVAL('answer.question'.question.questionId) AS score
FROM question, individual , answer
WHERE answer.individualId = question.individualId

so when question.questionId = 1 -> the query will return the score for
question1

gehegeradeaus@gmail.com wrote:
> I need this :
>
> SELECT question.questionId, individual.indivudal,
> EVAL('answer.question'.question.questionId) AS score
> FROM question, individual , answer
> WHERE answer.individualId = question.individualId
>
> so when question.questionId = 1 -> the query will return the score for
> question1

Does this do what you need?

SELECT q.questionId, i.individual,
CASE q.questionId
WHEN 1 THEN a.question1
WHEN 2 THEN a.question2
WHEN 3 THEN a.question3
WHEN 4 THEN a.question4
WHEN 5 THEN a.question5
WHEN 6 THEN a.question6
WHEN 7 THEN a.question7
WHEN 8 THEN a.question8
WHEN 9 THEN a.question9
END AS score
FROM question AS q
JOIN individual AS i
JOIN answer AS a ON USING (individualId);

Regards,
Bill K.

Bill Karwin schreef:

> gehegeradeaus@gmail.com wrote:
> > I need this :
> >
> > SELECT question.questionId, individual.indivudal,
> > EVAL('answer.question'.question.questionId) AS score
> > FROM question, individual , answer
> > WHERE answer.individualId = question.individualId
> >
> > so when question.questionId = 1 -> the query will return the score for
> > question1
>
> Does this do what you need?
>
> SELECT q.questionId, i.individual,
> CASE q.questionId
> WHEN 1 THEN a.question1
> WHEN 2 THEN a.question2
> WHEN 3 THEN a.question3
> WHEN 4 THEN a.question4
> WHEN 5 THEN a.question5
> WHEN 6 THEN a.question6
> WHEN 7 THEN a.question7
> WHEN 8 THEN a.question8
> WHEN 9 THEN a.question9
> END AS score
> FROM question AS q
> JOIN individual AS i
> JOIN answer AS a ON USING (individualId);
>
> Regards,
> Bill K.

Yes it does, thanks!