Check duplicate before insert query

[dextrocity]

Hey guys total newbie here. How can we check the database for duplicate records before we insert a record?

 

Thanks.

[blackwinter]

Well theres a few ways but to do it simply....

 

Select COUNT(*) FROM database WHERE username_column = $username_variable

[sKunKbad]

declare one field to be a primary key, mysql won't let you insert the same primary key again

[roopurt18]

The best way to do this would be to place a UNIQUE constraint on the proper columns in your table.  The database will handle the check for you when you attempt to INSERT or UPDATE and the query will fail.

[uramagget]

Well theres a few ways but to do it simply....

 

Select COUNT(*) FROM database WHERE username_column = $username_variable

In addition to that

 

$sql = "SELECT COUNT(*) FROM database WHERE username_column = $username_variable";
$result = mysql_query($sql);
if (mysql_num_rows($result) > 0)
{
//username taken
}
else
{
//proceed
}