\FBMYSQL\FR

If you have problems due to insufficient memory for large result sets, use the --quick option. This forces mysql to retrieve results from the server a row at a time rather than retrieving the entire result set and buffering it in memory before displaying it. This is done by returning the result set using the mysql_use_result() C API function in the client/server library rather than mysql_store_result().

Using mysql is very easy. Invoke it from the prompt of your command interpreter as follows:

shell> mysql db_name

Or:

shell> mysql --user=user_name --password db_name
Enter password: your_password

Then type an SQL statement, end it with ;, \g, or \G and press Enter.

Typing Control+C causes mysql to attempt to kill the current statement. If this cannot be done, or Control+C is typed again before the statement is killed, mysql exits.

You can execute SQL statements in a script file (batch file) like this:

shell> mysql db_name < script.sql > output.tab

On Unix, the mysql client logs statements executed interactively to a history file. See the section called lqMYSQL LOGGINGrq.  

MYSQL OPTIONS

mysql supports the following options, which can be specified on the command line or in the [mysql] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.6, lqUsing Option Filesrq.

* --help, -?

Display a help message and exit.

* --auto-rehash

Enable automatic rehashing. This option is on by default, which enables database, table, and column name completion. Use --disable-auto-rehash to disable rehashing. That causes mysql to start faster, but you must issue the rehash command or its \# shortcut if you want to use name completion.

To complete a name, enter the first part and press Tab. If the name is unambiguous, mysql completes it. Otherwise, you can press Tab again to see the possible names that begin with what you have typed so far. Completion does not occur if there is no default database.

Note
This feature requires a MySQL client that is compiled with the readline library. Typically, the readline library is not available on Windows.

* --auto-vertical-output

Cause result sets to be displayed vertically if they are too wide for the current window, and using normal tabular format otherwise. (This applies to statements terminated by ; or \G.)

* --batch, -B

Print results using tab as the column separator, with each row on a new line. With this option, mysql does not use the history file.

Batch mode results in nontabular output format and escaping of special characters. Escaping may be disabled by using raw mode; see the description for the --raw option.

* --binary-as-hex, -b

When this option is given, mysql displays binary data using hexadecimal notation (0xvalue). This occurs whether the overall output dislay format is tabular, vertical, HTML, or XML.

This option was added in MySQL 5.6.37.

* --binary-mode

This option helps when processing mysqlbinlog output that may contain BLOB values. By default, mysql translates \r\n in statement strings to \n and interprets \0 as the statement terminator. --binary-mode disables both features. It also disables all mysql commands except charset and delimiter in non-interactive mode (for input piped to mysql or loaded using the source command).

This option was added in MySQL 5.6.3.

* --bind-address=ip_address

On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.

This option is supported beginning with MySQL 5.6.1.

* --character-sets-dir=dir_name

The directory where character sets are installed. See Section 10.5, lqCharacter Set Configurationrq.

* --column-names

Write column names in results.

* --column-type-info

Display result set metadata.

* --comments, -c

Whether to preserve comments in statements sent to the server. The default is --skip-comments (discard comments), enable with --comments (preserve comments).

* --compress, -C

Compress all information sent between the client and the server if both support compression.

* --connect-expired-password

Indicate to the server that the client can handle sandbox mode if the account used to connect has an expired password. This can be useful for noninteractive invocations of mysql because normally the server disconnects noninteractive clients that attempt to connect using an account with an expired password. (See Section 6.3.6, lqPassword Expiration and Sandbox Moderq.) This option was added in MySQL 5.6.12.

* --database=db_name, -D db_name

The database to use. This is useful primarily in an option file.

* --debug[=debug_options], -# [debug_options]

Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:o,/tmp/mysql.trace.

This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option.

* --debug-check

Print some debugging information when the program exits.

* --debug-info, -T

Print debugging information and memory and CPU usage statistics when the program exits.

* --default-auth=plugin

A hint about the client-side authentication plugin to use. See Section 6.3.7, lqPluggable Authenticationrq.

* --default-character-set=charset_name

Use charset_name as the default character set for the client and connection.

This option can be useful if the operating system uses one character set and the mysql client by default uses another. In this case, output may be formatted incorrectly. You can usually fix such issues by using this option to force the client to use the system character set instead.

For more information, see Section 10.1.4, lqConnection Character Sets and Collationsrq, and Section 10.5, lqCharacter Set Configurationrq.

* --defaults-extra-file=file_name

Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. file_name is interpreted relative to the current directory if given as a relative path name rather than a full path name.

* --defaults-file=file_name

Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. file_name is interpreted relative to the current directory if given as a relative path name rather than a full path name.

Exception: Even with --defaults-file, client programs read .mylogin.cnf.

* --defaults-group-suffix=str

Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysql normally reads the [client] and [mysql] groups. If the --defaults-group-suffix=_other option is given, mysql also reads the [client_other] and [mysql_other] groups.

* --delimiter=str

Set the statement delimiter. The default is the semicolon character (;).

* --disable-named-commands

Disable named commands. Use the \* form only, or use named commands only at the beginning of a line ending with a semicolon (;). mysql starts with this option enabled by default. However, even with this option, long-format commands still work from the first line. See the section called lqMYSQL COMMANDSrq.

* --enable-cleartext-plugin

Enable the mysql_clear_password cleartext authentication plugin. (See Section 6.5.1.5, lqClient-Side Cleartext Pluggable Authenticationrq.) This option was added in MySQL 5.6.7.

* --execute=statement, -e statement

Execute the statement and quit. The default output format is like that produced with --batch. See Section 4.2.4, lqUsing Options on the Command Linerq, for some examples. With this option, mysql does not use the history file.

* --force, -f

Continue even if an SQL error occurs.

* --histignore

A colon-separated list of one or more patterns specifying statements to ignore for logging purposes. These patterns are added to the default pattern list ("*IDENTIFIED*:*PASSWORD*"). The value specified for this option affects logging of statements written to the history file. For more information, see the section called lqMYSQL LOGGINGrq. This option was added in MySQL 5.6.8.

* --host=host_name, -h host_name

Connect to the MySQL server on the given host.

* --html, -H

Produce HTML output.

* --ignore-spaces, -i

Ignore spaces after function names. The effect of this is described in the discussion for the IGNORE_SPACE SQL mode (see Section 5.1.8, lqServer SQL Modesrq).

* --init-command=str

SQL statement to execute after connecting to the server. If auto-reconnect is enabled, the statement is executed again after reconnection occurs.

* --line-numbers

Write line numbers for errors. Disable this with --skip-line-numbers.

* --local-infile[={0|1}]

Enable or disable LOCAL capability for LOAD DATA INFILE. For mysql, this capability is disabled by default. With no value, the option enables LOCAL. The option may be given as --local-infile=0 or --local-infile=1 to explicitly disable or enable LOCAL. Enabling local data loading has no effect if the server does not also support it; see Section 6.1.6, lqSecurity Issues with LOAD DATA LOCALrq

* --login-path=name

Read options from the named login path in the .mylogin.cnf login path file. A lqlogin pathrq is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See mysql_config_editor(1). This option was added in MySQL 5.6.6.

* --named-commands, -G

Enable named mysql commands. Long-format commands are permitted, not just short-format commands. For example, quit and \q both are recognized. Use --skip-named-commands to disable named commands. See the section called lqMYSQL COMMANDSrq.

* --no-auto-rehash, -A

This has the same effect as --skip-auto-rehash. See the description for --auto-rehash.

* --no-beep, -b

Do not beep when errors occur.

* --no-defaults

Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read.

The exception is that the .mylogin.cnf file, if it exists, is read in all cases. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. (.mylogin.cnf is created by the mysql_config_editor utility. See mysql_config_editor(1).)

* --one-database, -o

Ignore statements except those that occur while the default database is the one named on the command line. This option is rudimentary and should be used with care. Statement filtering is based only on USE statements.

Initially, mysql executes statements in the input because specifying a database db_name on the command line is equivalent to inserting USE db_name at the beginning of the input. Then, for each USE statement encountered, mysql accepts or rejects following statements depending on whether the database named is the one on the command line. The content of the statements is immaterial.

Suppose that mysql is invoked to process this set of statements:

DELETE FROM db2.t2;
USE db2;
DROP TABLE db1.t1;
CREATE TABLE db1.t1 (i INT);
USE db1;
INSERT INTO t1 (i) VALUES(1);
CREATE TABLE db2.t1 (j INT);

If the command line is mysql --force --one-database db1, mysql handles the input as follows:

* The DELETE statement is executed because the default database is db1, even though the statement names a table in a different database.

* The DROP TABLE and CREATE TABLE statements are not executed because the default database is not db1, even though the statements name a table in db1.

* The INSERT and CREATE TABLE statements are executed because the default database is db1, even though the CREATE TABLE statement names a table in a different database.

* --pager[=command]

Use the given command for paging query output. If the command is omitted, the default pager is the value of your PAGER environment variable. Valid pagers are less, more, cat [> filename], and so forth. This option works only on Unix and only in interactive mode. To disable paging, use --skip-pager. the section called lqMYSQL COMMANDSrq, discusses output paging further.

* --password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, mysql prompts for one.

Specifying a password on the command line should be considered insecure. See Section 6.1.2.1, lqEnd-User Guidelines for Password Securityrq. You can use an option file to avoid giving the password on the command line.

* --pipe, -W

On Windows, connect to the server using a named pipe. This option applies only if the server supports named-pipe connections.

* --plugin-dir=dir_name

The directory in which to look for plugins. Specify this option if the --default-auth option is used to specify an authentication plugin but mysql does not find it. See Section 6.3.7, lqPluggable Authenticationrq.

* --port=port_num, -P port_num

The TCP/IP port number to use for the connection.

* --print-defaults

Print the program name and all options that it gets from option files.

* --prompt=format_str

Set the prompt to the specified format. The default is mysql>. The special sequences that the prompt can contain are described in the section called lqMYSQL COMMANDSrq.

* --protocol={TCP|SOCKET|PIPE|MEMORY}

The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the permissible values, see Section 4.2.2, lqConnecting to the MySQL Serverrq.

* --quick, -q

Do not cache each query result, print each row as it is received. This may slow down the server if the output is suspended. With this option, mysql does not use the history file.

* --raw, -r

For tabular output, the lqboxingrq around columns enables one column value to be distinguished from another. For nontabular output (such as is produced in batch mode or when the --batch or --silent option is given), special characters are escaped in the output so they can be identified easily. Newline, tab, NUL, and backslash are written as \n, \t, \0, and \\. The --raw option disables this character escaping.

The following example demonstrates tabular versus nontabular output and the use of raw mode to disable escaping:

% mysql
mysql> SELECT CHAR(92);
+----------+
| CHAR(92) |
+----------+
| \        |
+----------+
% mysql -s
mysql> SELECT CHAR(92);
CHAR(92)
\\
% mysql -s -r
mysql> SELECT CHAR(92);
CHAR(92)
\

* --reconnect

If the connection to the server is lost, automatically try to reconnect. A single reconnect attempt is made each time the connection is lost. To suppress reconnection behavior, use --skip-reconnect.

* --safe-updates, --i-am-a-dummy, -U

Permit only those UPDATE and DELETE statements that specify which rows to modify by using key values. If you have set this option in an option file, you can override it by using --safe-updates on the command line. See the section called lqMYSQL TIPSrq, for more information about this option.

* --secure-auth

Do not send passwords to the server in old (pre-4.1) format. This prevents connections except for servers that use the newer password format. As of MySQL 5.6.7, this option is enabled by default; use --skip-secure-auth to disable it.

Note
Passwords that use the pre-4.1 hashing method are less secure than passwords that use the native password hashing method and should be avoided. Pre-4.1 passwords are deprecated and support for them will be removed in a future MySQL release. For account upgrade instructions, see Section 6.5.1.3, lqMigrating Away from Pre-4.1 Password Hashing and the mysql_old_password Pluginrq.

Note
This option is deprecated and will be removed in a future release. As of MySQL 5.7.5, it is always enabled and attempting to disable it produces an error.

* --server-public-key-path=file_name

The path name to a file containing the server RSA public key. The file must be in PEM format. The public key is used for RSA encryption of the client password for connections to the server made using accounts that authenticate with the sha256_password plugin. This option is ignored for client accounts that do not authenticate with that plugin. It is also ignored if password encryption is not needed, as is the case when the client connects to the server using an SSL connection.

The server sends the public key to the client as needed, so it is not necessary to use this option for RSA password encryption to occur. It is more efficient to do so because then the server need not send the key.

For additional discussion regarding use of the sha256_password plugin, including how to get the RSA public key, see Section 6.5.1.4, lqSHA-256 Pluggable Authenticationrq.

This option is available only if MySQL was built using OpenSSL.

* --shared-memory-base-name=name

On Windows, the shared-memory name to use, for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case sensitive.

The server must be started with the --shared-memory option to enable shared-memory connections.

* --show-warnings

Cause warnings to be shown after each statement if there are any. This option applies to interactive and batch mode.

* --sigint-ignore

Ignore SIGINT signals (typically the result of typing Control+C).

* --silent, -s

Silent mode. Produce less output. This option can be given multiple times to produce less and less output.

This option results in nontabular output format and escaping of special characters. Escaping may be disabled by using raw mode; see the description for the --raw option.

* --skip-column-names, -N

Do not write column names in results.

* --skip-line-numbers, -L

Do not write line numbers for errors. Useful when you want to compare result files that include error messages.

* --socket=path, -S path

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

* --ssl*

Options that begin with --ssl specify whether to connect to the server using SSL and indicate where to find SSL keys and certificates. See Section 6.4.5, lqCommand Options for Secure Connectionsrq.

* --table, -t

Display output in table format. This is the default for interactive use, but can be used to produce table output in batch mode.

* --tee=file_name

Append a copy of output to the given file. This option works only in interactive mode. the section called lqMYSQL COMMANDSrq, discusses tee files further.

* --unbuffered, -n

Flush the buffer after each query.

* --user=user_name, -u user_name

The MySQL user name to use when connecting to the server.

* --verbose, -v

Verbose mode. Produce more output about what the program does. This option can be given multiple times to produce more and more output. (For example, -v -v -v produces table output format even in batch mode.)

* --version, -V

Display version information and exit.

* --vertical, -E

Print query output rows vertically (one line per column value). Without this option, you can specify vertical output for individual statements by terminating them with \G.

* --wait, -w

If the connection cannot be established, wait and retry instead of aborting.

* --xml, -X

Produce XML output.

<field name="column_name">NULL</field>

The output when --xml is used with mysql matches that of mysqldump --xml. See mysqldump(1) for details.

The XML output also uses an XML namespace, as shown here:

shell> mysql --xml -uroot -e "SHOW VARIABLES LIKE 'version%'"
<?xml version="1.0"?>
<resultset statement="SHOW VARIABLES LIKE 'version%'" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<row>
<field name="Variable_name">version</field>
<field name="Value">5.0.40-debug</field>
</row>
<row>
<field name="Variable_name">version_comment</field>
<field name="Value">Source distribution</field>
</row>
<row>
<field name="Variable_name">version_compile_machine</field>
<field name="Value">i686</field>
</row>
<row>
<field name="Variable_name">version_compile_os</field>
<field name="Value">suse-linux-gnu</field>
</row>
</resultset>

(See Bug #25946.)

You can also set the following variables by using --var_name=value.

* connect_timeout

The number of seconds before connection timeout. (Default value is 0.)

* max_allowed_packet

The maximum size of the buffer for client/server communication. The default is 16MB, the maximum is 1GB.

* max_join_size

The automatic limit for rows in a join when using --safe-updates. (Default value is 1,000,000.)

* net_buffer_length

The buffer size for TCP/IP and socket communication. (Default value is 16KB.)

* select_limit

The automatic limit for SELECT statements when using --safe-updates. (Default value is 1,000.)

MYSQL COMMANDS

mysql sends each SQL statement that you issue to the server to be executed. There is also a set of commands that mysql itself interprets. For a list of these commands, type help or \h at the mysql> prompt:

mysql> help
List of all MySQL commands:
Note that all text commands must be first on line and end with ';'
?         (\?) Synonym for `help'.
clear     (\c) Clear command.
connect   (\r) Reconnect to the server. Optional arguments are db and host.
delimiter (\d) Set statement delimiter.
edit      (\e) Edit command with $EDITOR.
ego       (\G) Send command to mysql server, display result vertically.
exit      (\q) Exit mysql. Same as quit.
go        (\g) Send command to mysql server.
help      (\h) Display this help.
nopager   (\n) Disable pager, print to stdout.
notee     (\t) Don't write into outfile.
pager     (\P) Set PAGER [to_pager]. Print the query results via PAGER.
print     (\p) Print current command.
prompt    (\R) Change your mysql prompt.
quit      (\q) Quit mysql.
rehash    (\#) Rebuild completion hash.
source    (\.) Execute an SQL script file. Takes a file name as an argument.
status    (\s) Get status information from the server.
system    (\!) Execute a system shell command.
tee       (\T) Set outfile [to_outfile]. Append everything into given
               outfile.
use       (\u) Use another database. Takes database name as argument.
charset   (\C) Switch to another charset. Might be needed for processing
               binlog with multi-byte charsets.
warnings  (\W) Show warnings after every statement.
nowarning (\w) Don't show warnings after every statement.
For server side help, type 'help contents'

If mysql is invoked with the --binary-mode option, all mysql commands are disabled except charset and delimiter in non-interactive mode (for input piped to mysql or loaded using the source command).

Each command has both a long and short form. The long form is not case sensitive; the short form is. The long form can be followed by an optional semicolon terminator, but the short form should not.

The use of short-form commands within multiple-line /* ... */ comments is not supported.

* 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 the section called lqMYSQL SERVER-SIDE HELPrq.

* 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 as INDE 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 23.8.17, lqC API Support for Multiple Statement Executionrq), and for parsing the body of stored procedures and functions, triggers, and events (see Section 20.1, lqDefining Stored Programsrq).

* 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 vi if 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.)

* 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 the mysql 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 notee command. 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).

Here are a few tips about the pager command:

* 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.

You can also combine the tee and pager functions. Have a tee file enabled and pager set to less, and you are able to browse the results using the less program and still have everything appended into a file the same time. The difference between the Unix tee used with the pager command and the mysql built-in tee command is that the built-in tee works even if you do not have the Unix tee available. The built-in tee also logs everything that is printed on the screen, whereas the Unix tee used with pager does not log quite that much. Additionally, tee file logging can be turned on and off interactively from within mysql. This is useful when you want to log some queries to a file, but not others.

The prompt command reconfigures the default mysql> prompt. The string for defining the prompt can contain the following special sequences.

You can set the prompt in several ways:

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

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, lqUsing Option Filesrq.) 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> "

* 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>

MYSQL LOGGING

On Unix, the mysql client logs statements executed interactively to a history file. By default, this file is named .mysql_history in your home directory. To specify a different file, set the value of the MYSQL_HISTFILE environment variable. How Logging Occurs.PP Statement logging occurs as follows:

* Statements are logged only when executed interactively. Statements are noninteractive, for example, when read from a file or a pipe. It is also possible to suppress statement logging by using the --batch or --execute option.

* Statements are ignored and not logged if they match any pattern in the lqignorerq list. This list is described later.

* mysql logs each nonignored, nonempty statement line individually.

* If a nonignored statement spans multiple lines (not including the terminating delimiter), mysql concatenates the lines to form the complete statement, maps newlines to spaces, and logs the result, plus a delimiter.

Consequently, an input statement that spans multiple lines can be logged twice. Consider this input:

mysql> SELECT
    -> 'Today is'
    -> ,
    -> CURDATE()
    -> ;

In this case, mysql logs the lqSELECTrq, lq'Today is'rq, lq,rq, lqCURDATE()rq, and lq;rq lines as it reads them. It also logs the complete statement, after mapping SELECT\n'Today is'\n,\nCURDATE() to SELECT 'Today is' , CURDATE(), plus a delimiter. Thus, these lines appear in logged output:

SELECT
'Today is'
,
CURDATE()
;
SELECT 'Today is' , CURDATE();

As of MySQL 5.6.8, mysql ignores for logging purposes statements that match any pattern in the lqignorerq list. By default, the pattern list is "*IDENTIFIED*:*PASSWORD*", to ignore statements that refer to passwords. Pattern matching is not case sensitive. Within patterns, two characters are special:

* ? matches any single character.

* * matches any sequence of zero or more characters.

To specify additional patterns, use the --histignore option or set the MYSQL_HISTIGNORE environment variable. (If both are specified, the option value takes precedence.) The value should be a colon-separated list of one or more patterns, which are appended to the default pattern list.

Patterns specified on the command line might need to be quoted or escaped to prevent your command interpreter from treating them specially. For example, to suppress logging for UPDATE and DELETE statements in addition to statements that refer to passwords, invoke mysql like this:

shell> mysql --histignore="*UPDATE*:*DELETE*"

Controlling the History File.PP The .mysql_history file should be protected with a restrictive access mode because sensitive information might be written to it, such as the text of SQL statements that contain passwords. See Section 6.1.2.1, lqEnd-User Guidelines for Password Securityrq.

If you do not want to maintain a history file, first remove .mysql_history if it exists. Then use either of the following techniques to prevent it from being created again:

* Set the MYSQL_HISTFILE environment variable to /dev/null. To cause this setting to take effect each time you log in, put it in one of your shell's startup files.

* Create .mysql_history as a symbolic link to /dev/null; this need be done only once:

shell> ln -s /dev/null $HOME/.mysql_history

MYSQL SERVER-SIDE HELP

mysql> help search_string

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. The proper operation of this command requires that the help tables in the mysql database be initialized with help topic information (see Section 5.1.10, lqServer-Side Helprq).

If there is no match for the search string, the search fails:

mysql> help me
Nothing found
Please try to run 'help contents' for a list of all accessible topics

Use help contents to see a list of the help categories:

mysql> help contents
You asked for help about help category: "Contents"
For more information, type 'help <item>', where <item> is one of the
following categories:
   Account Management
   Administration
   Data Definition
   Data Manipulation
   Data Types
   Functions
   Functions and Modifiers for Use with GROUP BY
   Geographic Features
   Language Structure
   Plugins
   Storage Engines
   Stored Routines
   Table Maintenance
   Transactions
   Triggers

If the search string matches multiple items, mysql shows a list of matching topics:

mysql> help logs
Many help items for your request exist.
To make a more specific request, please type 'help <item>',
where <item> is one of the following topics:
   SHOW
   SHOW BINARY LOGS
   SHOW ENGINE
   SHOW LOGS

Use a topic as the search string to see the help entry for that topic:

mysql> help show binary logs
Name: 'SHOW BINARY LOGS'
Description:
Syntax:
SHOW BINARY LOGS
SHOW MASTER LOGS
Lists the binary log files on the server. This statement is used as
part of the procedure described in [purge-binary-logs], that shows how
to determine which logs can be purged.
mysql> SHOW BINARY LOGS;
+---------------+-----------+
| Log_name      | File_size |
+---------------+-----------+
| binlog.000015 |    724935 |
| binlog.000016 |    733481 |
+---------------+-----------+

The search string can contain the wildcard characters % and _. These have the same meaning as for pattern-matching operations performed with the LIKE operator. For example, HELP rep% returns a list of topics that begin with rep:

mysql> HELP rep%
Many help items for your request exist.
To make a more specific request, please type 'help <item>',
where <item> is one of the following
topics:
   REPAIR TABLE
   REPEAT FUNCTION
   REPEAT LOOP
   REPLACE
   REPLACE FUNCTION

EXECUTING SQL STATEMENTS FROM A TEXT FILE

The mysql client typically is used interactively, like this:

shell> mysql db_name

However, it is also possible to put your SQL statements in a file and then tell mysql to read its input from that file. To do so, create a text file text_file that contains the statements you wish to execute. Then invoke mysql as shown here:

shell> mysql db_name < text_file

If you place a USE db_name statement as the first statement in the file, it is unnecessary to specify the database name on the command line:

shell> mysql < text_file

If you are already running mysql, you can execute an SQL script file using the source command or \. command:

mysql> source file_name
mysql> \. file_name

Sometimes you may want your script to display progress information to the user. For this you can insert statements like this:

SELECT '<info_to_display>' AS ' ';

The statement shown outputs <info_to_display>.

You can also invoke mysql with the --verbose option, which causes each statement to be displayed before the result that it produces.

mysql ignores Unicode byte order mark (BOM) characters at the beginning of input files. Previously, it read them and sent them to the server, resulting in a syntax error. Presence of a BOM does not cause mysql to change its default character set. To do that, invoke mysql with an option such as --default-character-set=utf8.

For more information about batch mode, see Section 3.5, lqUsing mysql in Batch Moderq.  

MYSQL TIPS

This section describes some techniques that can help you use mysql more effectively.  

Input-Line Editing

mysql supports input-line editing, which enables you to modify the current input line in place or recall previous input lines. For example, the left-arrow and right-arrow keys move horizontally within the current input line, and the up-arrow and down-arrow keys move up and down through the set of previously entered lines. Backspace deletes the character before the cursor and typing new characters enters them at the cursor position. To enter the line, press Enter.

On Windows, the editing key sequences are the same as supported for command editing in console windows. On Unix, the key sequences depend on the input library used to build mysql (for example, the libedit or readline library).

Documentation for the libedit and readline libraries is available online. To change the set of key sequences permitted by a given input library, define key bindings in the library startup file. This is a file in your home directory: .editrc for libedit and .inputrc for readline.

For example, in libedit, Control+W deletes everything before the current cursor position and Control+U deletes the entire line. In readline, Control+W deletes the word before the cursor and Control+U deletes everything before the current cursor position. If mysql was built using libedit, a user who prefers the readline behavior for these two keys can put the following lines in the .editrc file (creating the file if necessary):

bind "^W" ed-delete-prev-word
bind "^U" vi-kill-line-prev

To see the current set of key bindings, temporarily put a line that says only bind at the end of .editrc. mysql will show the bindings when it starts.  

Unicode Support on Windows

Windows provides APIs based on UTF-16LE for reading from and writing to the console. As of MySQL 5.6.2, the mysql client for Windows is able to use these APIs. As of 5.6.3, the Windows installer creates an item in the MySQL menu named MySQL command line client - Unicode. This item invokes the mysql client with properties set to communicate through the console to the MySQL server using Unicode.

To take advantage of this support manually, run mysql within a console that uses a compatible Unicode font and set the default character set to a Unicode character set that is supported for communication with the server:

1. Open a console window.

2. Go to the console window properties, select the font tab, and choose Lucida Console or some other compatible Unicode font. This is necessary because console windows start by default using a DOS raster font that is inadequate for Unicode.

3. Execute mysql.exe with the --default-character-set=utf8 (or utf8mb4) option. This option is necessary because utf16le is not supported as a connection character set.

With those changes, mysql will use the Windows APIs to communicate with the console using UTF-16LE, and communicate with the server using UTF-8. (The menu item mentioned previously sets the font and character set as just described.)

To avoid those steps each time you run mysql, you can create a shortcut that invokes mysql.exe. The shortcut should set the console font to Lucida Console or some other compatible Unicode font, and pass the --default-character-set=utf8 (or utf8mb4) option to mysql.exe.

Alternatively, create a shortcut that only sets the console font, and set the character set in the [mysql] group of your my.ini file:

[mysql]
default-character-set=utf8

Displaying Query Results Vertically

Some query results are much more readable when displayed vertically, instead of in the usual horizontal table format. Queries can be displayed vertically by terminating the query with \G instead of a semicolon. For example, longer text values that include newlines often are much easier to read with vertical output:

mysql> SELECT * FROM mails WHERE LENGTH(txt) < 300 LIMIT 300,1\G
*************************** 1. row ***************************
  msg_nro: 3068
     date: 2000-03-01 23:29:50
time_zone: +0200
mail_from: Monty
    reply: monty@no.spam.com
  mail_to: "Thimble Smith" <tim@no.spam.com>
      sbj: UTF-8
      txt: >>>>> "Thimble" == Thimble Smith writes:
Thimble> Hi.  I think this is a good idea.  Is anyone familiar
Thimble> with UTF-8 or Unicode? Otherwise, I'll put this on my
Thimble> TODO list and see what happens.
Yes, please do that.
Regards,
Monty
     file: inbox-jani-1
     hash: 190402944
1 row in set (0.09 sec)

Using the --safe-updates Option

For beginners, a useful startup option is --safe-updates (or --i-am-a-dummy, which has the same effect). It is helpful for cases when you might have issued a DELETE FROM tbl_name statement but forgotten the WHERE clause. Normally, such a statement deletes all rows from the table. With --safe-updates, you can delete rows only by specifying the key values that identify them. This helps prevent accidents.

When you use the --safe-updates option, mysql issues the following statement when it connects to the MySQL server:

SET sql_safe_updates=1, sql_select_limit=1000, max_join_size=1000000;

See Section 5.1.5, lqServer System Variablesrq.

The SET statement has the following effects:

* You are not permitted to execute an UPDATE or DELETE statement unless you specify a key constraint in the WHERE clause or provide a LIMIT clause (or both). For example:

UPDATE tbl_name SET not_key_column=val WHERE key_column=val;
UPDATE tbl_name SET not_key_column=val LIMIT 1;

* The server limits all large SELECT results to 1,000 rows unless the statement includes a LIMIT clause.

* The server aborts multiple-table SELECT statements that probably need to examine more than 1,000,000 row combinations.

To specify limits different from 1,000 and 1,000,000, you can override the defaults by using the --select_limit and --max_join_size options:

shell> mysql --safe-updates --select_limit=500 --max_join_size=10000

Disabling mysql Auto-Reconnect

If the mysql client loses its connection to the server while sending a statement, it immediately and automatically tries to reconnect once to the server and send the statement again. However, even if mysql succeeds in reconnecting, your first connection has ended and all your previous session objects and settings are lost: temporary tables, the autocommit mode, and user-defined and session variables. Also, any current transaction rolls back. This behavior may be dangerous for you, as in the following example where the server was shut down and restarted between the first and second statements without you knowing it:

mysql> SET @a=1;
Query OK, 0 rows affected (0.05 sec)
mysql> INSERT INTO t VALUES(@a);
ERROR 2006: MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    1
Current database: test
Query OK, 1 row affected (1.30 sec)
mysql> SELECT * FROM t;
+------+
| a    |
+------+
| NULL |
+------+
1 row in set (0.05 sec)

The @a user variable has been lost with the connection, and after the reconnection it is undefined. If it is important to have mysql terminate with an error if the connection has been lost, you can start the mysql client with the --skip-reconnect option.

For more information about auto-reconnect and its effect on state information when a reconnection occurs, see Section 23.8.16, lqControlling Automatic Reconnection Behaviorrq.  

COPYRIGHT

Copyright © 1997, 2017, Oracle and/or its affiliates. All rights reserved.

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/.

SEE ALSO

AUTHOR

Index

NAME

SYNOPSIS

DESCRIPTION

MYSQL OPTIONS

MYSQL COMMANDS

MYSQL LOGGING

MYSQL SERVER-SIDE HELP

EXECUTING SQL STATEMENTS FROM A TEXT FILE

MYSQL TIPS

Input-Line Editing

Unicode Support on Windows

Displaying Query Results Vertically

Using the --safe-updates Option

Disabling mysql Auto-Reconnect

COPYRIGHT

SEE ALSO

AUTHOR