Multiple Table Query

[phpretard]

Why won't this work?

 

 

 

$result = mysql_query("SELECT table1.username, table2.username FROM table1, table2 WHERE username = '".$_POST['username']."'");

 

 

 

[BlueSkyIS]

$result = mysql_query("SELECT table1.username, table2.username FROM table1, table2 WHERE username = '".$_POST['username']."'") or die(mysql_error());

 

what "won't work"?

 

 

[gbunny]

You have to associate your where clause with the table so it would look more like this

 

SELECT table1.username, table2.username
         FROM table1, table2
         where table1.username = '".$_POST['username']."'
                  AND 
                  table2.username = '".$_POST['username']."'"

[BlueSkyIS]

yes. if you use mysql_error(), you'd probably get an error about 'ambiguous field name' or whatever. i was hoping to get you to use mysql_error() to let PHP tell you what's wrong. 

[phpretard]

So here is what I replaced it with and it tells give the error assign when a username does not exist.

 

$check = mysql_query("SELECT Administrators.username, Appraisers.username  FROM Administrators, Appraisers where Administrators.username = '".$_POST['username']."' OR  Appraisers.username = '".$_POST['username']."'")or die(mysql_error());

 

 

Any pointers?

[cooldude832]

how about using a JOIN instead

[phpretard]

I wish I knew how...

[cooldude832]

did u try to learn?  learning doesn't just happen you have to facilitate it

[phpretard]

Demeaning and true.

[phpretard]

Left Join, Right Join, array Join, Join the party?

 

How about just a point in the right direction...

 

 

[cooldude832]

http://dev.mysql.com/doc/refman/5.0/en/join.html

 

Now keep facilitating it

[phpretard]

You see...

 

I have read through this BEFORE I POSTED and am not sure which applies to a login.

 

 

 

JOIN 
JOIN works in the same way as the SELECT statement above—it returns a result set with columns from different tables. The advantage of using an explicit JOIN over an implied one is greater control over your result set, and possibly improved performance when many tables are involved. 

There are several types of JOIN—LEFT, RIGHT, and FULL OUTER; INNER; and CROSS. The type you use is determined by the results you want to see. For example, using a LEFT OUTER JOIN will return all relevant rows from the first table listed, while potentially dropping rows from the second table listed if they don’t have information that correlates in the first table. 

This differs from an INNER JOIN or an implied JOIN. An INNER JOIN will only return rows for which there is data in both tables. 

Use the following JOIN statement for the first SELECT query above:
SELECT table1.column1, table2.column2 FROM table1 INNER JOIN table2
ON table1.column1 = table2.column1; 

[javedkarim]

try this out and see whats the error

 

$result = mysql_query("SELECT table1.username, table2.username FROM table1, table2 WHERE username = '".$_POST['username']."'") or die ( mysql_error() ) ;

 

I hope it will solve the problem

[phpretard]

I have no Idea what this means...

 

Column 'username' in where clause is ambiguous

[discomatt]

You probably want this

 

<?php

$query = <<<QUERY
(SELECT username FROM table1 WHERE username = '{$_POST['username']}')
UNION
(SELECT username FROM table2 WHERE username = '{$_POST['username']}')
QUERY;

?>