KEY question

[DjRubbish]

When creating a table on a database. can anyone tell me what this does?

KEY customer_id (customer_id)

I don't understand why I need to repeat the column name in the brackets. Am I just giving the key a name and telling it which column the key represents?

Likewise, I'm not too sure about:

KEY full_name(last_name, first_name)

I guess this second one concatenates the values from the last_name and first_name columns. But I'd like to be sure.

I've tried to RTFM at mysql.com but it's not working for me (scary dense text and a search button that doesn't send me exactly where I need to be) 😉

Thx

[zhabala]

Yes, you are perfectly right. You are creating index under given name and created on defined columns.

Z.