Login help: in_array

[rodnice]

Ok, so I'm trying to build my first PHP project, but was having problems with the user sign up section of code.

When someone goes to sign-up, my page will check to make sure that the required fields aren't empty, and that they contain encrypted and cleaned up data for the MySQL database. Most importantly, I wanna make sure that an error is sent to the user if there is a duplicate user name. I wan't the same to occur if there is a duplicate email address.

1st, connect to DB
2nd, select DB
3rd, query the user and email fields
4th, make sure there is no match in the user field from what's in $REQUEST['user']
make sure there is no match in the user field from what's in $REQUEST['email']

(Sorry, I don't have my code with me to post 🙁 )

How do I check to make sure there are no duplicates entered in the database for user and set an error variable to echo later? I tried a loop, but it echo's the error for each cycle through the loop. I tried in_array() to search for just that one occurence using the $_REQUEST variable as the needle but PHP didn't like that idea.

I'm stuck at a logic wall 🙁

[NogDog]

Generally I follow this pattern:

1. Set each affected field in the database to not allow duplicates, either by being the primary key or having a unique-type index assigned.

2. Go ahead and do the insert query to the DB with the customer-supplied values.

3. If the query fails, check to see if it's a duplicate key error (in MySQL check to see if mysql_errno() == 1062). If it is, tell the user the name/email is already in use.

[rodnice]

Excellent!

However, I would I generate a separate error for each field so that the user is not guessing as to which field is causing the error?

[NogDog]

You should be able to parse the message from mysql_error() to find which field it's complaining about. It will be in the format "Duplicate entry 'entered_value' for key column_name".