Thread:Project:Support desk/db connection refused: 1.15.1 to 1.19 upgrade

Hello, I am trying to upgrade from 1.15.1 to 1.19. I have updated the files from the tar file. Now I'm running "php update.php" from the maintenance directory. First I got the error: DB connection error: No such file or directory (localhost), so I changed localhost to 127.0.0.1. Now I get this error: DB connection error: Connection refused (127.0.0.1). I have the correct database name, username and password (unchanged from before). Any suggestions? Thanks. Julie