Stopping Duplicate DB Entries

Anon

I've been attempting to create a query that will check a specific field within a table to see if it matches with what the user has entered, and if there is a duplicate, notify the user.

I've been using the following code.

$query = "SELECT * FROM table_name WHERE no_dupe_field='test'";

i know this is probally so simple it hurts, but i fail to see how i can check the result of this query for a yes - there are duplicates / no there aren't result.

i've tried running if(run query command)

to see if its true/false but it seems to do nothing.

I hope this makes sense and if enough information.

I'm using mysql, in case thats some majorly needed info.

Thank you in advanced for what i'm sure will be your wonderfully enthusiastic help.

Life would be so boring if there weren't people around to ask dumb questions.

tomhath

Check out a function called mysql_num_rows

Anon

mysql_num_rows, Ah.. now lets see..

i did try it.. returns how many rows, in this case, in the query.. so i figure... there will be nothing, 0, null, nada if there is a result to the query... correct?

so...

if(mysql_num_rows (query command here)){
// query found a duplicate
echo "blah blah you had a duplicate";
}

..or..

$query_result = query command here

if(mysql_num_rows ($query_result)){
// query found a duplicate
echo "blah blah you had a duplicate";
}

Actually.. i think they're both the same thing..

But is that the correct syntax to use?

If so, i have and it just lies and say's there's no duplicate, when i know there is.

I'll look further into the num_rows command.. But if you can spoon-feed the information i'll be happy.

Thank again for all help.

You know you want to tell me more..

Anon

I do beleive i did it..

the mysql_num_rows field worked... when i typed out the examples of what i "had" tried in the last post i realised i had been attempting to run the num_rows command in everyway BUT the one below. I tried it.. and it worked... Ta Da

$query = "SELECT * FROM table_name WHERE field='field_searched'";
$query_result = run query;

if (mysql_num_rows($query_result)) {
duplicate found, return result
echo "blah blah duplicate found.";
}

So it was the correct function to use...

thanks for all your help