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Checking if a record exists befor insert

Posted: Fri Jul 12, 2002 1:59 am
by Martin L
Hi

What is the best practice for checking if a record exists before inserting a new one?

Thanks in advance

Martin L

Posted: Fri Jul 12, 2002 3:28 am
by mikeq
One way is to code it into your application:

$Query = "select * from mytable where myfield='thevalue'";

$Result = MySQL_Query($Query);
$NumberRecords = MySQL_Num_Rows($Result);

if ($NumberRecords==0){
//no record exists do your insert
}
else{
//display error
}

Another way is to identify unique/primary keys on your table, when you try to insert a record that violates the unique/primary key then MySQL will generate an error, just capture that error and display a warning to the user.

Mike