「mysql – The MySQL Command-Line Tool」

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mysql,MySQL的命令行工具,是一个简单的SQL SHELL。改命令即支持交互式使用,也支持非交互式使用。

命令行语法格式

mysql [options] db_name

命令简述

mysql is a simple SQL shell with input line editing capabilities. It supports interactive and noninteractive

use. When used interactively, query results are presented in an ASCII-table format. When used

noninteractively (for example, as a filter), the result is presented in tab-separated format. The output

format can be changed using command options.

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().

Note

Alternatively, MySQL Shell offers access to the X DevAPI. For details, see Section 3.8, “MySQL Shell

User Guide”.

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=your_password db_name

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

Typing Control+C interrupts the current statement if there is one, or cancels any partial input line

otherwise.

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

“MYSQL LOGGING”.

命令行选项及含义

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 5.2.6, “Using Option Files”.

· –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-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).

· –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.

· –character-sets-dir=dir_name

The directory where character sets are installed. See Section 11.5, “Character Set Configuration”.

· –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).

Note

As of MySQL 5.7.7, the mysql client always passes optimizer hints to the server, regardless of

whether this option is given. To ensure that optimizer hints are not stripped if you are using an

older version of the mysql client with a version of the server that understands optimizer hints,

invoke mysql with the –comments option.

· –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 7.3.7, “Password Expiration and Sandbox Mode”.) This option was added in MySQL 5.7.2.

· –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 7.3.8, “Pluggable

Authentication”.

· –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 11.1.4, “Connection Character Sets and Collations”, and Section 11.5,

“Character Set Configuration”.

· –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 “MYSQL COMMANDS”.

· –enable-cleartext-plugin

Enable the mysql_clear_password cleartext authentication plugin. (See Section 7.5.1.8, “The Cleartext

Client-Side Authentication Plugin”.)

· –execute=statement, -e statement

Execute the statement and quit. The default output format is like that produced with –batch. See

Section 5.2.4, “Using Options on the Command Line”, 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, and to syslog if the –syslog

option is given. For more information, see the section called “MYSQL LOGGING”.

· –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 6.1.8, “Server SQL Modes”).

· –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. 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 has no effect if the server does not also support it.

· –login-path=name

Read options from the named login path in the .mylogin.cnf login path file. A “login path” 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).

· –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 “MYSQL COMMANDS”.

· –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 “MYSQL COMMANDS”, 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 7.1.2.1, “End-User

Guidelines for Password Security”. 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 7.3.8, “Pluggable

Authentication”.

· –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 “MYSQL COMMANDS”.

· –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 5.2.2, “Connecting to the MySQL Server”.

· –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 “boxing” 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 “MYSQL TIPS”, 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 5.7.5, this option is deprecated and will be removed in a future MySQL release. It is always

enabled and attempting to disable it (–skip-secure-auth, –secure-auth=0) produces an error. Before

MySQL 5.7.5, this option is enabled by default but can be disabled.

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

is removed in MySQL 5.7.5. For account upgrade instructions, see Section 7.5.1.3, “Migrating Away

from Pre-4.1 Password Hashing and the mysql_old_password Plugin”.

· –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 7.5.1.4, “The SHA-256 Authentication Plugin”.

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 7.4.5, “Command Options for Secure Connections”.

· –syslog, -j

This option causes mysql to send interactive statements to the system logging facility. On Unix, this is

syslog; on Windows, it is the Windows Event Log. The destination where logged messages appear is system

dependent. On Linux, the destination is often the /var/log/messages file.

Here is a sample of output generated on Linux by using –syslog. This output is formatted for

readability; each logged message actually takes a single line.

Mar 7 12:39:25 myhost MysqlClient[20824]:
SYSTEM_USER:’oscar’, MYSQL_USER:’my_oscar’, CONNECTION_ID:23,

DB_SERVER:’127.0.0.1′, DB:’–‘, QUERY:’USE test;’
Mar 7 12:39:28 myhost MysqlClient[20824]:
SYSTEM_USER:’oscar’, MYSQL_USER:’my_oscar’, CONNECTION_ID:23,

DB_SERVER:’127.0.0.1′, DB:’test’, QUERY:’SHOW TABLES;’

For more information, see the section called “MYSQL LOGGING”.

The –syslog option was added in MySQL 5.7.1.

· –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 “MYSQL COMMANDS”, discusses tee files further.

· –tls-version=protocol_list

The protocols permitted by the client for encrypted connections. The value is a comma-separated list

containing one or more protocol names. The protocols that can be named for this option depend on the SSL

library used to compile MySQL. For details, see Section 7.4.3, “Secure Connection Protocols and

Ciphers”.

This option was added in MySQL 5.7.10.

· –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.)

在MYSQL中支持的命令

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 the current input statement.

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.

resetconnection(\x) Clean session context.

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

“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 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 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 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.)

· 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 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.

┌───────┬────────────────────────────────────────┐

│Option │ Description │

├───────┼────────────────────────────────────────┤

│\C │ The current connection identifier │

│ │ (MySQL 5.7.6 and up) │

├───────┼────────────────────────────────────────┤

│\c │ A counter that increments for each │

│ │ statement you issue │

├───────┼────────────────────────────────────────┤

│\D │ The full current date │

├───────┼────────────────────────────────────────┤

│\d │ The default database │

├───────┼────────────────────────────────────────┤

│\h │ The server host │

├───────┼────────────────────────────────────────┤

│\l │ The current delimiter │

├───────┼────────────────────────────────────────┤

│\m │ Minutes of the current time │

├───────┼────────────────────────────────────────┤

│\n │ A newline character │

├───────┼────────────────────────────────────────┤

│\O │ The current month in three-letter │

│ │ format (Jan, Feb, …) │

├───────┼────────────────────────────────────────┤

│\o │ The current month in numeric format │

├───────┼────────────────────────────────────────┤

│\P │ am/pm │

├───────┼────────────────────────────────────────┤

│\p │ The current TCP/IP port or socket file │

├───────┼────────────────────────────────────────┤

│\R │ The current time, in 24-hour military │

│ │ time (0–23) │

├───────┼────────────────────────────────────────┤

│\r │ The current time, standard 12-hour │

│ │ time (1–12) │

├───────┼────────────────────────────────────────┤

│\S │ Semicolon │

├───────┼────────────────────────────────────────┤

│\s │ Seconds of the current time │

├───────┼────────────────────────────────────────┤

│\t │ A tab character │

├───────┼────────────────────────────────────────┤

│\U │ │

│ │
Your full user_name@host_name

│ │ account name │

├───────┼────────────────────────────────────────┤

│\u │ Your user name │

├───────┼────────────────────────────────────────┤

│\v │ The server version │

├───────┼────────────────────────────────────────┤

│\w │ The current day of the week in │

│ │ three-letter format (Mon, Tue, …) │

├───────┼────────────────────────────────────────┤

│\Y │ The current year, four digits │

├───────┼────────────────────────────────────────┤

│\y │ The current year, two digits │

├───────┼────────────────────────────────────────┤

│\_ │ A space │

├───────┼────────────────────────────────────────┤

│\ │ A space (a space follows the │

│ │ backslash) │

├───────┼────────────────────────────────────────┤

│\’ │ Single quote │

├───────┼────────────────────────────────────────┤

│\” │ Double quote │

├───────┼────────────────────────────────────────┤

│\\ │ A literal \ backslash character │

├───────┼────────────────────────────────────────┤

│\x │ │

│ │ x, for any “x” not listed above │

└───────┴────────────────────────────────────────┘

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 5.2.6, “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> ”

· 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

The mysql client can do these types of logging for statements executed interactively:

· On Unix, mysql writes the statements 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.

· On all platforms, if the –syslog option is given, mysql writes the statements to the system logging
facility. On Unix, this is syslog; on Windows, it is the Windows Event Log. The destination where logged

messages appear is system dependent. On Linux, the destination is often the /var/log/messages file.

The following discussion describes characteristics that apply to all logging types and provides information

specific to each logging type. How Logging Occurs.PP For each enabled logging destination, 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 “ignore” 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 “SELECT”, “’Today is’”, “,”, “CURDATE()”, and “;” 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();

mysql ignores for logging purposes statements that match any pattern in the “ignore” 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 7.1.2.1, “End-User Guidelines for Password Security”.

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
syslog Logging Characteristics.PP If the –syslog option is given, mysql writes interactive statements to

the system logging facility. Message logging has the following characteristics.

Logging occurs at the “information” level. This corresponds to the LOG_INFO priority for syslog on

Unix/Linux syslog capability and to EVENTLOG_INFORMATION_TYPE for the Windows Event Log. Consult your system

documentation for configuration of your logging capability.

Message size is limited to 1024 bytes.

Messages consist of the identifier MysqlClient followed by these values:

· SYSTEM_USER

The system user name (login name) or — if the user is unknown.

· MYSQL_USER

The MySQL user name (specified with the –user option) or — if the user is unknown.

· CONNECTION_ID:

The client connection identifier. This is the same as the CONNECTION_ID() function value within the

session.

· DB_SERVER

The server host or — if the host is unknown.

· DB

The default database or — if no database has been selected.

· QUERY

The text of the logged statement.

Here is a sample of output generated on Linux by using –syslog. This output is formatted for readability;

each logged message actually takes a single line.

Mar 7 12:39:25 myhost MysqlClient[20824]:
SYSTEM_USER:’oscar’, MYSQL_USER:’my_oscar’, CONNECTION_ID:23,

DB_SERVER:’127.0.0.1′, DB:’–‘, QUERY:’USE test;’
Mar 7 12:39:28 myhost MysqlClient[20824]:
SYSTEM_USER:’oscar’, MYSQL_USER:’my_oscar’, CONNECTION_ID:23,

DB_SERVER:’127.0.0.1′, DB:’test’, QUERY:’SHOW TABLES;’

MySQL服务端帮助

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 6.1.10, “Server-Side

Help”).

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

执行文本文件中的SQL语句

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 4.5, “Using mysql in Batch Mode”.

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; the mysql client for

Windows is able to use these APIs. 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.

  1. 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.

  1. 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 6.1.5, “Server System Variables”.

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 27.8.16, “Controlling Automatic Reconnection Behavior”.

参考文献