Does MySQL table row contain two values

I have a table with two columns:

ID1 | ID2
---------
 1  | A
 3  | V
 1  | C
 4  | B
 5  | Q
 1  | S

And I want to be 开发者_开发问答able to find out if any row has, say ID1 = 5 and ID2 = Q , and return a true / false value.

Yes, Of course

SELECT * FROM table where ID1='5' and ID2='Q'

PHP _{(I am just guessing this backend)}

$query = "SELECT * FROM table where ID1='5' and ID2='Q'";
$result = mysql_query($query);
if(mysql_num_rows($result)) { return true; }
else { return false; }

1 means TRUE for mysql

SELECT 1
FROM your_table
WHERE ID1 = 5 AND ID2 = 'Q'

for example this?

SELECT 1
FROM TABLE
WHERE ID1 = 5 AND ID2 = 'Q'

Efficient query for your purpose (faster than other examples):

SELECT 1 FROM table where ID1='5' and ID2='Q' LIMIT 1

PHP sample:

<?php
    $query = "SELECT 1 FROM table where ID1='5' and ID2='Q' LIMIT 1";
    echo bool(mysql_num_row(mysql_query($query)));
?>