MySQL修改提示符

 help [arg], \h [arg], \? [arg], ? [arg]

Display a help message listing the available mysql commands.

If you provide an argument to the help command, mysql uses it as a search string to access server-side help from the contents of the MySQL Reference Manual. For more information, see Section 4.5.1.4, “mysql Server-Side Help”.

 charset charset_name, \C charset_name

Change the default character set and issue a SET NAMES statement. This enables the character set to remain synchronized on the client and server if mysql is run with auto-reconnect enabled (which is not recommended), because the specified character set is used for reconnects.

 clear, \c

Clear the current input. Use this if you change your mind about executing the statement that you are entering.

 connect [db_name host_name]], \r [db_name host_name]]

Reconnect to the server. The optional database name and host name arguments may be given to specify the default database or the host where the server is running. If omitted, the current values are used.

 delimiter str, \d str

Change the string that mysql interprets as the separator between SQL statements. The default is the semicolon character (;).

The delimiter string can be specified as an unquoted or quoted argument on the delimiter command line. Quoting can be done with either single quote ('), double quote ("), or backtick (`) characters. To include a quote within a quoted string, either quote the string with a different quote character or escape the quote with a backslash (\) character. Backslash should be avoided outside of quoted strings because it is the escape character for MySQL. For an unquoted argument, the delimiter is read up to the first space or end of line. For a quoted argument, the delimiter is read up to the matching quote on the line.

mysql interprets instances of the delimiter string as a statement delimiter anywhere it occurs, except within quoted strings. Be careful about defining a delimiter that might occur within other words. For example, if you define the delimiter as X, you will be unable to use the word INDEX in statements. mysql interprets this asINDE followed by the delimiter X.

When the delimiter recognized by mysql is set to something other than the default of ;, instances of that character are sent to the server without interpretation. However, the server itself still interprets ; as a statement delimiter and processes statements accordingly. This behavior on the server side comes into play for multiple-statement execution (see Section 27.8.17, “C API Support for Multiple Statement Execution”), and for parsing the body of stored procedures and functions, triggers, and events (see Section 23.1, “Defining Stored Programs”).

 edit, \e

Edit the current input statement. mysql checks the values of the EDITOR and VISUAL environment variables to determine which editor to use. The default editor is viif neither variable is set.

The edit command works only in Unix.

 ego, \G

Send the current statement to the server to be executed and display the result using vertical format.

 exit, \q

Exit mysql.

 go, \g

Send the current statement to the server to be executed.

 nopager, \n

Disable output paging. See the description for pager.

The nopager command works only in Unix.

 notee, \t

Disable output copying to the tee file. See the description for tee.

 nowarning, \w

Disable display of warnings after each statement.

 pager [command], \P [command]

Enable output paging. By using the --pager option when you invoke mysql, it is possible to browse or search query results in interactive mode with Unix programs such as less, more, or any other similar program. If you specify no value for the option, mysql checks the value of the PAGER environment variable and sets the pager to that. Pager functionality works only in interactive mode.

Output paging can be enabled interactively with the pager command and disabled with nopager. The command takes an optional argument; if given, the paging program is set to that. With no argument, the pager is set to the pager that was set on the command line, or stdout if no pager was specified.

Output paging works only in Unix because it uses the popen() function, which does not exist on Windows. For Windows, the tee option can be used instead to save query output, although it is not as convenient as pager for browsing output in some situations.

 print, \p

Print the current input statement without executing it.

 prompt [str], \R [str]

Reconfigure the mysql prompt to the given string. The special character sequences that can be used in the prompt are described later in this section.

If you specify the prompt command with no argument, mysql resets the prompt to the default of mysql>.

 quit, \q

Exit mysql.

 rehash, \#

Rebuild the completion hash that enables database, table, and column name completion while you are entering statements. (See the description for the --auto-rehash option.)

 resetconnection, \x

Reset the connection to clear the session state. This command was added in MySQL 5.7.3.

Resetting a connection has effects similar to mysql_change_user() or an auto-reconnect except that the connection is not closed and reopened, and re-authentication is not done. See Section 27.8.7.3, “mysql_change_user()”) and see Section 27.8.16, “Controlling Automatic Reconnection Behavior”).

This example shows how resetconnection clears a value maintained in the session state:

mysql> SELECT LAST_INSERT_ID(3);
+-------------------+
| LAST_INSERT_ID(3) |
+-------------------+
|                 3 |
+-------------------+


mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
|                3 |
+------------------+


mysql> resetconnection;


mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
|                0 |
+------------------+ 

 source file_name, \. file_name

Read the named file and executes the statements contained therein. On Windows, you can specify path name separators as / or \\.

 status, \s

Provide status information about the connection and the server you are using. If you are running in --safe-updates mode, status also prints the values for themysql variables that affect your queries.

 system command, \! command

Execute the given command using your default command interpreter.

The system command works only in Unix.

 tee [file_name], \T [file_name]

By using the --tee option when you invoke mysql, you can log statements and their output. All the data displayed on the screen is appended into a given file. This can be very useful for debugging purposes also. mysql flushes results to the file after each statement, just before it prints its next prompt. Tee functionality works only in interactive mode.

You can enable this feature interactively with the tee command. Without a parameter, the previous file is used. The tee file can be disabled with the noteecommand. Executing tee again re-enables logging.

 use db_name, \u db_name

Use db_name as the default database.

 warnings, \W

Enable display of warnings after each statement (if there are any).

You can use it to write to a file and the results go only to the file:

mysql> pager cat > /tmp/log.txt

You can also pass any options for the program that you want to use as your pager:

mysql> pager less -n -i -S

In the preceding example, note the -S option. You may find it very useful for browsing wide query results. Sometimes a very wide result set is difficult to read on the screen. The -S option to less can make the result set much more readable because you can scroll it horizontally using the left-arrow and right-arrow keys. You can also use -S interactively within less to switch the horizontal-browse mode on and off. For more information, read the less manual page:

shell> man less

The -F and -X options may be used with less to cause it to exit if output fits on one screen, which is convenient when no scrolling is necessary:

mysql> pager less -n -i -S -F -X

You can specify very complex pager commands for handling query output:

mysql> pager cat | tee /dr1/tmp/res.txt \ | tee /dr2/tmp/res2.txt | less -n -i -S

In this example, the command would send query results to two files in two different directories on two different file systems mounted on /dr1 and /dr2, yet still display the results onscreen using less.

Use an environment variable. You can set the MYSQL_PS1 environment variable to a prompt string. For example:

shell> export MYSQL_PS1="(\u@\h) [\d]> "

Use a command-line option. You can set the --prompt option on the command line to mysql. For example:

shell> mysql --prompt="(\u@\h) [\d]> " 

(user@host) [database]>

Use an option file. You can set the prompt option in the [mysql] group of any MySQL option file, such as /etc/my.cnf or the .my.cnf file in your home directory. For example:

[mysql] 

In this example, note that the backslashes are doubled. If you set the prompt using the prompt option in an option file, it is advisable to double the backslashes when using the special prompt options. There is some overlap in the set of permissible prompt options and the set of special escape sequences that are recognized in option files. (The rules for escape sequences in option files are listed in Section 4.2.6, “Using Option Files”.) The overlap may cause you problems if you use single backslashes. For example, \s is interpreted as a space rather than as the current seconds value. The following example shows how to define a prompt within an option file to include the current time in HH:MM:SS> format:

[mysql] prompt="\\r:\\m:\\s> "

prompt=(\\u@\\h) [\\d]>\\_

Set the prompt interactively. You can change your prompt interactively by using the prompt (or \R) command. For example:

mysql> prompt (\u@\h) [\d]>\_
PROMPT set to '(\u@\h) [\d]>\_' 

(user@host) [database]> (user@host) [database]> prompt
Returning to default PROMPT of mysql> mysql>