Question

I have a ‘users’ SQL table structure like this (the ID is randomly generated for certain reasons, it is not auto-incremented):

ID    name     deleted    lastActive
3242  Joe      0          20-6-2012 23:14
2234  Dave     0          20-6-2012 23:13
2342  Simon    1          20-6-2012 23:02
9432  Joe      1          20-6-2012 22:58

In one query (to avoid concurrent queries adding the same name twice), I need to add a new user to the table IF there is not already a record with that name AND deleted = 0. I then need to know the result of the query (if the user was added) so that I can report back saying if the user was added or not. Is this possible using PHP?

I could do this (but as a prepared statement, of course!):

INSERT INTO users (ID, name) VALUES ($id, $name) 
    WHERE NOT EXISTS (SELECT 1 FROM users WHERE name = $name AND deleted = 0)

But how can I know if the user was added or not?

Answer 1

If you’re using mysqli, you can use the mysqli_stmt_affected_rows() function to determine how many rows were inserted.

Similarly, you can use the PDOStatement::rowCount() method to determine how many rows were inserted for PDO.

Both functions will tell you the number of rows that were inserted as a result of the query.