The \help command can be used with or without a parameter. When used without a parameter a general help message is printed including information about the available MySQL Shell commands, global objects and main help categories.

When used with a parameter, the parameter is used to search the available help based on the mode which the MySQL Shell is currently running in. The parameter can be a word, a command, an API function, or part of an SQL statement. The following categories exist:

To search for help on a topic, for example an API function, use the function name as a pattern. You can use the wildcard characters ? to match any single character and * to match multiple characters in a search. The wildcard characters can be used one or more times in the pattern. The following namespaces can also be used when searching for help:

For example to search for help on a topic, issue \help pattern and:

Depending on the search pattern provided, one or more results could be found. If only one help topic contains the search pattern in its title, that help topic is displayed. If multiple topic titles match the pattern but one is an exact match, that help topic is displayed, followed by a list of the other topics with pattern matches in their titles. If no exact match is identified, a list of topics with pattern matches in their titles is displayed. If a list of topics is returned, you can select a topic to view from the list by entering the command again with an extended search pattern that matches the title of the relevant topic.

The \connect command is used to connect to a MySQL Server. See Section 4.3, “MySQL Shell Connections”.

For example:

\connect root@localhost:3306

If a password is required you are prompted for it.

Use the --mysqlx (--mx) option to create a session using the X Protocol to connect to MySQL server instance. For example:

\connect --mysqlx root@localhost:33060

Use the --mysql (--mc) option to create a ClassicSession, enabling you to use classic MySQL protocol to issue SQL directly on a server. For example:

\connect --mysql root@localhost:3306

Use the --ssh option to create or reuse an SSH tunnel that provides an encrypted connection to the MySQL server instance. The use of AdminAPI commands is not supported over connections made from MySQL Shell using SSH tunneling. Supply the URI for connection to the SSH server in the format [user@]hostname[:port], followed by the MySQL instance URI, for example:

\connect --ssh root@198.51.100.4:2222 root@localhost:3306

When you use the --ssh option, the port for connection to the MySQL server instance must be specified in the MySQL instance URI.

An SSH tunnel set up using the \connect command must use the default SSH configuration file and identity file. For instructions to set these and further information on SSH tunnel connections from MySQL Shell, see Section 4.3.6, “Using an SSH Tunnel”. You can set up an SSH tunnel using the shell.connect() method or on the command line to get additional setup options. Once established, an SSH tunnel can be shared between connections to the same host from the same user connecting from the same instance, whatever setup method was originally used.

The \reconnect command is specified without any parameters or options. If the connection to the server is lost, you can use the \reconnect command, which makes MySQL Shell try several reconnection attempts for the session using the existing connection parameters. If those attempts are unsuccessful, you can make a fresh connection using the \connect command and specifying the connection parameters.

The \disconnect command, is also specified without any parameters or options. The command disconnects MySQL Shell's global session (the session represented by the session global object) from the currently connected MySQL server instance, so that you can close the connection but still continue to use MySQL Shell.

If the connection to the server is lost, you can use the \reconnect command, which makes MySQL Shell try several reconnection attempts for the session using the existing connection parameters. If those attempts are unsuccessful, you can make a fresh connection using the \connect command and specifying the connection parameters.

The \status command displays information about the current global connection. This includes information about the server connected to, the character set in use, uptime, and so on.

The \source command or its alias \. can be used in MySQL Shell's interactive mode to execute code from a script file at a given path. For example:

\source /tmp/mydata.sql

You can execute either SQL, JavaScript or Python code. The code in the file is executed using the active language, so to process SQL code the MySQL Shell must be in SQL mode.

For compatibility with the mysql client, in SQL mode only, you can execute code from a script file using the source command with no backslash and an optional SQL delimiter.  source or the alias \. (which does not use an SQL delimiter) can be used both in MySQL Shell's interactive mode for SQL, to execute a script directly, and in a file of SQL code processed in batch mode, to execute a further script from within the file. So with MySQL Shell in SQL mode, you could now execute the script in the /tmp/mydata.sql file from either interactive mode or batch mode using any of these three commands:

source /tmp/mydata.sql;
source /tmp/mydata.sql
\. /tmp/mydata.sql  

The command \source /tmp/mydata.sql is also valid, but in interactive mode only.

In interactive mode, the \source, \. or source command itself is added to the MySQL Shell history, but the contents of the executed script file are not added to the history.

The \use command enables you to choose which schema is active, for example:

\use schema_name

The \use command requires a global development session to be active. The \use command sets the current schema to the specified schema_name and updates the db variable to the object that represents the selected schema.

The \history command lists the commands you have issued previously in MySQL Shell. Issuing \history shows history entries in the order that they were issued with their history entry number, which can be used with the \history delete entry_number command.

The \history command provides the following options:

The history is not saved between sessions by default, so when you exit MySQL Shell the history of what you issued during the current session is lost. If you want to keep the history across sessions, enable the MySQL Shell history.autoSave option. For more information, see Section 5.5, “Code History”.

When you have disabled the autocomplete name cache feature, use the \rehash command to manually update the cache. For example, after you load a new schema by issuing the \use schema command, issue \rehash to update the autocomplete name cache. After this autocomplete is aware of the names used in the database, and you can autocomplete text such as table names and so on. See Section 5.3, “Code Autocompletion”.

The \option command enables you to query and change MySQL Shell configuration options in all modes. You can use the \option command to list the configuration options that have been set and show how their value was last changed. You can also use it to set and unset options, either for the session, or persistently in the MySQL Shell configuration file. For instructions and a list of the configuration options, see Section 13.4, “Configuring MySQL Shell Options”.

You can configure MySQL Shell to use an external pager to read long onscreen output, such as the online help or the results of SQL queries. See Section 4.6, “Using a Pager”.

The \show command runs the named report, which can be either a built-in MySQL Shell report or a user-defined report that has been registered with MySQL Shell. You can specify the standard options for the command, and any options or additional arguments that the report supports. The \watch command runs a report in the same way as the \show command, but then refreshes the results at regular intervals until you cancel the command using Ctrl + C. For instructions, see Section 10.1.5, “Running MySQL Shell Reports”.

The \edit (\e) command opens a command in the default system editor for editing, then presents the edited command in MySQL Shell for execution. The command can also be invoked using the key combination Ctrl-X Ctrl-E. For details, see Section 5.4, “Editing Code”.

The \system (\!) command runs the operating system command that you specify as an argument to the command, then displays the output from the command in MySQL Shell. MySQL Shell returns an error if it was unable to execute the command. The output from the command is returned as given by the operating system, and is not processed by MySQL Shell's JSON wrapping function or by any external pager tool that you have specified to display output.

The query_attribute command, and session.setQueryAttributes method, enable you to define query attributes for your SQL queries. The MySQL Shell functionality is identical to that of the MySQL client.

For more information, see the following:

Setting Query Attributes Example

The following examples set the attributes att1 and att2 with the values val1 and val2 respectively:

Retrieving Query Attributes Example

Attributes can be retrieved using the mysql_query_attribute_string() function.

For example: