MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

4.2.2 Specifying Program Options

There are several ways to specify options for MySQL programs:

Options are processed in order, so if an option is specified multiple times, the last occurrence takes precedence. The following command causes mysql to connect to the server running on localhost:

mysql -h example.com -h localhost

If conflicting or related options are given, later options take precedence over earlier options. The following command runs mysql in no column names mode:

mysql --column-names --skip-column-names

MySQL programs determine which options are given first by examining environment variables, then by processing option files, and then by checking the command line. This means that environment variables have the lowest precedence and command-line options the highest.

For the server, one exception applies: The mysqld-auto.cnf option file in the data directory is processed last, so it takes precedence even over command-line options.

You can take advantage of the way that MySQL programs process options by specifying default option values for a program in an option file. That enables you to avoid typing them each time you run the program while enabling you to override the defaults if necessary by using command-line options.