How do I make sure that duplicate data isn't stored in a table?
In other words, if record 1 has the email address "firstname.lastname@example.org", I want to make sure that no other records that are created can have the email address email@example.com.
Right now, I'm solving this problem through PHP by checking if that email address exists before inserting it. But isn't there a way to do this through mysql? I though there was a certain way to set up a table so that duplicate data couldn't be inserted.