How to check whether a username is available from 3 tables

Question

Here is a query with which I am checking whether a username is available or not in one table

 $query=mysql_query("SELECT * from tb_sponsar where username='$username'");

But,I am having two more tables named tb_company and tb_school and both tables have this field named username now I want to have a query that checks usernames from all the three tables...I am new to php so don't know how to do it.can anyone please help me in this regard?

I tried it like this

 $query=mysql_query("SELECT * from tb_sponsar where username='$username'" && "SELECT * from tb_company where username='$username'");

but after applying this query it is giving false result

http://stackoverflow.com/questions/12859942/why-shouldnt-i-use-mysql-functions-in-php — Nabil Kadimi, Jun 17 '14 at 08:00
`SELECT * FROM table1,tabl2,table3 WHERE username='$username'` — Hanky Panky, Jun 17 '14 at 08:01
it is checking the condition right from first table but is not working properly in second table — user3572583, Jun 17 '14 at 08:04

score 0 · Answer 1 · answered Jun 17 '14 at 08:07

0

Just try

  $query=mysql_query("SELECT * from tb_sponsar where 
username='$username'" AND "SELECT * from tb_company where username='$username'");

answered Jun 17 '14 at 08:07

Arshid KV

8,979
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score 0 · Answer 2 · answered Jun 17 '14 at 08:07

0

Try this

$query=mysql_query("SELECT username from tb_sponsar where username='{$username}'"
. " UNION SELECT username from tb_company where username='{$username}'"
. " UNION SELECT username from tb_table3 where username='{$username}'");

answered Jun 17 '14 at 08:07

Samar Haider

872
10
21

when i am applying this query it is showing the same result for every username that is not available even if the username does not exist – user3572583 Jun 17 '14 at 08:10

score 0 · Accepted Answer · answered Jun 17 '14 at 08:14

Tray using UNION keyword to combine tables:

$query=mysql_query("SELECT username from tb_sponsar where username='$username' UNION SELECT username from tb_company where username='$username'");

You can also use JOIN but you need to have a relation between those tables.

score 0 · Answer 4 · answered Jun 17 '14 at 08:21

0

try this bro

$query=mysql_query("SELECT * from tb_sponsar where username='$username' AND SELECT * from tb_company where username='$username' AND SELECT * from tb_school where username='$username'");

answered Jun 17 '14 at 08:21

wrecklez

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2
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How to check whether a username is available from 3 tables

4 Answers4