Mailing List Database: No Duplicate Entries

[bradleydh]

I know I can have mySQL make sure that there are no duplicate entries, but I have already used that tag for one of the rows, and it will not let me do it for a second.

I have a mailing list database with the following rows:
ID
Email ($email)
Name ($name)

I only want this to concern the email row, but how would I write that if the email address already exists in the database, then echo a message that they are already subscribed.

Any help would be greatly appreciated.

You will have to excuse my lack of php knowledge... I am just learning.

[Mordecai]

$result = mysql_query("SELECT * FROM table WHERE email='".$email."'");
if (mysql_num_rows($result) >= 1) { // don't insert, echo error
  echo("You've already subscribed!");
}
else { // insert
  mysql_query("INSERT INTO table...");
}

Something like this should do the trick.
Mysql_num_rows returns the number of rows returned by the query.

[ahundiak]

You can also create an unique index to preclude duplicate entries.

CREATE UNIQUE INDEX name ON table(email);

You will have to do some more work to tell the user exactly why the insert/update failed.