sql query syntax problem

[zodehala]

http://img241.imageshack.us/img241/6599/phpan7.jpg

why is following query result empty

SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` =22 AND `parentid` =0;

[abduraooft]

`parentid` =22 AND `parentid` =0; Are your trying to get the result of OR
A filed can't hold two different values in a single row.

[zodehala]

Are your trying to get the result of OR
A filed can't hold two different values in a single row.

so

how can i select username which parentid are 0 and 22 ?

[Fumigator]

Multiple personality disorder is a human condition which fortunately does not spread to databases. As has already been mentioned, it's impossible for a single column in a single row to contain more than one value. If the value is 0, then it can't be 22, and visa-versa. If the value is "0,22" then the value is neither 0 nor 22, it's "0,22".

[_Aerospace_Eng_]

Use
SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` =22 OR `parentid` =0;
which has already been stated. I suggest doing some mysql tutorials.

[derzok]

Yes, you need to use an OR statement instead of an AND. What you're asking it to do is select all of the rows where the parentid is equal to both 0 AND 22 at the same time - which is impossible. No number can be 0 and 22 at the same time. You want to select the rows where the parentid is 0 or the parentid is 0.

One of the downfalls of an english based syntax :rolleyes:

[technica]

Try this query, this will work:

SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` in (22,0);

If this query gives syntax error then use this:

SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` in ('22','0');

This query will fetch all the records whith threadid=22 and parentid qual to 22 and 0

Hope this helps

[zodehala]

Try this query, this will work:

SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` in (22,0);

If this query gives syntax error then use this:

SELECT `postid` , `threadid` , `parentid` , `username` , `title` , `pagetext`
FROM `post`
WHERE `threadid` =22 AND `parentid` in ('22','0');

This query will fetch all the records whith threadid=22 and parentid qual to 22 and 0

Hope this helps

thanx u r perfect

[Fumigator]

To clarify the IN(x,x) syntax is an alternative to normal OR syntax, so you're still not testing if parentid = 0 and parentid = 22. But whatever. :)

[zodehala]

To clarify the IN(x,x) syntax is an alternative to normal OR syntax, so you're still not testing if parentid = 0 and parentid = 22. But whatever. :)

but it is running:thumbsup: