[Resolved] Select statement from two table

[eli03]

How do i select an id from two table, example

if table1.id1 is not equal to table2.id2
then print id1 else if equal print nothing.

thanks

[rachel2004]

<?php

$sql = "SELECT DISTINCT table1.id
        FROM table1
        LEFT JOIN table2
        ON (table1.id != table2.id)";

$result = mysql_query($sql, $db_connection);

while ($row = mysql_fetch_array($result))
{
    echo"<li>".$row['id']."<br>";
}

?>

This will only work if you only want either the "id" column from table1 or from table2, but not both at the same time unless you rename one or both columns OR you use column aliases during the query.

Hope this helped.

[eli03]

i follow your code here it is

<?php 

$sql = "SELECT DISTINCT account.account_id as id FROM account LEFT JOIN domains ON (account.account_id != domains.domain_id)"; 

$result = mysql_query($sql); 

while ($row = mysql_fetch_array($result)) 
{ 
    echo"<li>$row[id]<br>"; 
} 

?> 

but still the same, it show all the id in table1. just like

select * from account;

:queasy: what im done wrong?

I want to get the table1 id w/ no pair in table 2 id. exmple

table1 table2
id id

1 1
2 4
3 5
4
5

if i have table like that, since number 1,4,5 in table1 have pair w/ table2, the remaining number will be 2,3. how do i get that id?

Thanks for helping🙂

[Weedpacket]

select distinct account.account_id as id from account, domains where account.account_id==domains.domain_id

[eli03]

:queasy: i don't get any id comming from dbase, when i used this

$sql = "SELECT DISTINCT account.account_id AS id FROM account, domains WHERE account.account_id==domains.domain_id ";

when you say " WHERE account.account_id==domains.domain_id " it means it will display all the pair. but i want the id in table1 w/ no pair in table2

thanks again

[freebie]

Note, I don't think you want the ==, rather just =

[rachel2004]

I should've added a WHERE clause. This should work:

<?php 
$sql = "SELECT DISTINCT account.account_id as id FROM account LEFT JOIN domains ON (account.account_id = domains.domain_id)
WHERE domains.domain_id IS NULL"; 

$result = mysql_query($sql); 

while ($row = mysql_fetch_array($result)) 
{ 
    echo"<li>$row['id']"; 
} 

?>  

[eli03]

what is NULL for? The idea is correct but i gives me a blank result. 🙁 Why is this happening... i can't finished my project:queasy:

Thanks again, any suggestion?

[rachel2004]

I removed the != sign and changed it to = which is what I had tested it with on MySQL, but I copied your code and forgot to take it out.

Anyway, I edited my code in my post. Look at it again and give it a try.

[eli03]

Yehey....😃 it works. thank you so much rachel 🙂 and also to all the guys here who help me. thanks