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

Display a help message listing the available mysql commands.显示一条帮助消息，列出可用的mysql命令。

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. 如果为help命令提供参数，mysql会将其用作搜索字符串，以从mysql参考手册的内容中访问服务器端帮助。For more information, see Section 4.5.1.4, “mysql Client Server-Side Help”.有关更多信息，请参阅第4.5.1.4节，“mysql客户端-服务器端帮助”。

charset charset_name, \C charset_name

Change the default character set and issue a SET NAMES statement. 更改默认字符集并发出SET NAMES语句。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.如果mysql在启用自动重新连接的情况下运行（不建议），这使得字符集在客户端和服务器上保持同步，因为指定的字符集用于重新连接。

clear, \c

Clear the current input. Use this if you change your mind about executing the statement that you are entering.清除当前输入。如果您改变了执行所输入语句的想法，请使用此选项。

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.重新连接到服务器。可以提供可选的数据库名称和主机名参数，以指定默认数据库或服务器运行的主机。如果省略，则使用当前值。

If the connect command specifies a host name argument, that host takes precedence over any --dns-srv-name option given at mysql startup to specify a DNS SRV record.如果connect命令指定了主机名参数，则该主机优先于mysql启动时给出的任何--dns-srv-name选项，以指定DNS SRV记录。

delimiter str, \d str

Change the string that mysql interprets as the separator between SQL statements. The default is the semicolon character (;).更改mysql解释为SQL语句之间分隔符的字符串。默认值是分号字符（;）。

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. 分隔符字符串可以在分隔符命令行上指定为无引号或有引号的参数。引用可以使用单引号（'）、双引号（"）或反引号（`）字符。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. 要在引号字符串中包含引号，请用不同的引号字符对字符串进行引号，或用反斜杠（\）字符转义引号。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.应避免在引号字符串之外使用反斜杠，因为它是MySQL的转义符。对于未加引号的参数，分隔符被读取到第一个空格或行末。对于带引号的参数，分隔符被读取到行上的匹配引号。

mysql interprets instances of the delimiter string as a statement delimiter anywhere it occurs, except within quoted strings. mysql将分隔符字符串的实例解释为它出现的任何地方的语句分隔符，但引号内的字符串除外。Be careful about defining a delimiter that might occur within other words. 在定义可能出现在其他单词中的分隔符时要小心。For example, if you define the delimiter as X, it is not possible to use the word INDEX in statements. 例如，如果将分隔符定义为X，则无法在语句中使用单词INDEX。mysql interprets this as INDE followed by the delimiter X.mysql将其解释为INDE，后跟分隔符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. 当mysql识别的分隔符设置为默认值;以外的值时，该字符的实例被发送到服务器而不进行解释。However, the server itself still interprets ; as a statement delimiter and processes statements accordingly. 然而，服务器本身仍在解释；作为语句分隔符，并相应地处理语句。This behavior on the server side comes into play for multiple-statement execution (see Multiple Statement Execution Support), and for parsing the body of stored procedures and functions, triggers, and events (see Section 25.1, “Defining Stored Programs”).服务器端的这种行为适用于多语句执行（请参阅多语句执行支持），以及解析存储过程和函数、触发器和事件的主体（请参阅第25.1节，“定义存储程序”）。

edit, \e

Edit the current input statement. 编辑当前输入语句。mysql checks the values of the EDITOR and VISUAL environment variables to determine which editor to use. mysql检查EDITOR和VISUAL环境变量的值，以确定使用哪个编辑器。The default editor is vi if neither variable is set.如果两个变量都没有设置，默认编辑器是vi。

The edit command works only in Unix.edit命令仅在Unix中有效。

ego, \G

Send the current statement to the server to be executed and display the result using vertical format.将当前语句发送到要执行的服务器，并使用垂直格式显示结果。

exit, \q

Exit mysql.退出mysql。

go, \g

Send the current statement to the server to be executed.将当前语句发送到要执行的服务器。

nopager, \n

Disable output paging. See the description for pager.禁用输出分页。请参阅pager的说明。

The nopager command works only in Unix.nopager命令仅在Unix中有效。

notee, \t

Disable output copying to the tee file. See the description for tee.禁止将输出复制到tee文件。请参阅tee的说明。

nowarning, \w

Disable display of warnings after each statement.禁止在每条语句后显示警告。

pager [command], \P [command]

Enable output paging. 启用输出分页。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. 通过在调用mysql时使用--pager选项，可以在Unix程序（如less、more或任何其他类似程序）的交互模式下浏览或搜索查询结果。If you specify no value for the option, mysql checks the value of the PAGER environment variable and sets the pager to that. 如果您没有为该选项指定值，mysql会检查PAGER环境变量的值，并将分页器设置为该值。Pager functionality works only in interactive mode.寻呼机功能仅在交互模式下工作。

Output paging can be enabled interactively with the pager command and disabled with nopager. 输出分页可以使用pager命令交互式启用，也可以使用nopager命令禁用。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.该命令接受一个可选参数；如果给定，则将寻呼程序设置为该值。在没有参数的情况下，分页器被设置为在命令行上设置的分页器，如果没有指定分页器，则设置为stdout。

Output paging works only in Unix because it uses the popen() function, which does not exist on Windows. 输出分页仅在Unix中有效，因为它使用popen()函数，而Windows上不存在该函数。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.对于Windows，可以使用tee选项来保存查询输出，尽管在某些情况下，它不如分页器浏览输出方便。

print, \p

Print the current input statement without executing it.打印当前输入语句而不执行它。

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.将mysql提示符重新配置为给定的字符串。本节稍后将介绍提示符中可以使用的特殊字符序列。

If you specify the prompt command with no argument, mysql resets the prompt to the default of mysql>.如果指定不带参数的prompt命令，mysql会将prompt重置为mysql>的默认值。

query_attributes name value [name value ...]

Define query attributes that apply to the next query sent to the server. 定义应用于发送到服务器的下一个查询的查询属性。For discussion of the purpose and use of query attributes, see Section 9.6, “Query Attributes”.有关查询属性的目的和使用的讨论，请参阅第9.6节，“查询属性”。

The query_attributes command follows these rules:query_attributes命令遵循以下规则：

quit, \q

Exit mysql.退出mysql。

rehash, \#

Rebuild the completion hash that enables database, table, and column name completion while you are entering statements. 重建完成哈希，使您在输入语句时能够完成数据库、表和列名。(See the description for the --auto-rehash option.)（请参阅--auto-rehash选项的说明。）

resetconnection, \x

Reset the connection to clear the session state. This includes clearing any current query attributes defined using the query_attributes command.重置连接以清除会话状态。这包括清除使用query_attributes命令定义的任何当前查询属性。

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. 重置连接的效果类似于mysql_change_user()或自动重新连接，除了连接不会关闭和重新打开，也不会进行重新身份验证。See mysql_change_user(), and Automatic Reconnection Control.请参阅mysql_change_user()和自动重新连接控制。

This example shows how resetconnection clears a value maintained in the session state:此示例显示了resetconnection如何清除会话状态中维护的值：

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. 读取指定的文件并执行其中包含的语句。On Windows, specify path name separators as / or \\.在Windows上，将路径名分隔符指定为/或\\。

Quote characters are taken as part of the file name itself. For best results, the name should not include space characters.引用字符被视为文件名本身的一部分。为了获得最佳效果，名称不应包含空格字符。

status, \s

Provide status information about the connection and the server you are using. 提供有关连接和您正在使用的服务器的状态信息。If you are running with --safe-updates enabled, status also prints the values for the mysql variables that affect your queries.如果您在启用--safe-updates的情况下运行，status还会打印影响查询的mysql变量的值。

system command, \! command

Execute the given command using your default command interpreter.使用默认命令解释器执行给定的命令。

Prior to MySQL 8.0.19, the system command works only in Unix. As of 8.0.19, it also works on Windows.在MySQL 8.0.19之前，system命令仅在Unix中有效。从8.0.19开始，它也适用于Windows。

tee [file_name], \T [file_name]

By using the --tee option when you invoke mysql, you can log statements and their output. 通过在调用mysql时使用--tee选项，您可以记录语句及其输出。All the data displayed on the screen is appended into a given file. 屏幕上显示的所有数据都附加到给定的文件中。This can be very useful for debugging purposes also. 这对于调试目的也非常有用。mysql flushes results to the file after each statement, just before it prints its next prompt. mysql在每条语句之后，就在打印下一个提示之前，将结果刷新到文件中。Tee functionality works only in interactive mode.T恤功能仅在交互模式下有效。

You can enable this feature interactively with the tee command. Without a parameter, the previous file is used. 您可以使用tee命令以交互方式启用此功能。如果没有参数，则使用前一个文件。The tee file can be disabled with the notee command. Executing tee again re-enables logging.可以使用notee命令禁用tee文件。再次执行tee将重新启用日志记录。

use db_name, \u db_name

Use db_name as the default database.使用db_name作为默认数据库。

warnings, \W

Enable display of warnings after each statement (if there are any).允许在每条语句后显示警告（如果有的话）。

You can use it to write to a file and the results go only to the file:您可以使用它写入文件，结果只会写入文件：

mysql> pager cat > /tmp/log.txt

You can also pass any options for the program that you want to use as your pager:您还可以传递要用作寻呼机的程序的任何选项：

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. 在前面的示例中，请注意-S选项。您可能会发现它对于浏览广泛的查询结果非常有用。Sometimes a very wide result set is difficult to read on the screen. 有时，屏幕上很难看到非常宽的结果集。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. -S选项可以使结果集更具可读性，因为您可以使用左箭头和右箭头键水平滚动它。You can also use -S interactively within less to switch the horizontal-browse mode on and off. 您还可以在less中交互式地使用-S来打开和关闭水平浏览模式。For more information, read the less manual page:有关更多信息，请阅读less手册页：

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:如果输出适合一个屏幕，则可以使用较少的-F和-X选项使其退出，这在不需要滚动时很方便：

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

You can specify very complex pager commands for handling query output:您可以指定非常复杂的分页器命令来处理查询输出：

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.在这个例子中，该命令将向/dr1和/dr2上安装的两个不同文件系统上的两个目录中的两个文件发送查询结果，但仍然使用较少的内容在屏幕上显示结果。

Use an environment variable.使用环境变量。 You can set the MYSQL_PS1 environment variable to a prompt string. For example:您可以将MY_RESPS1环境变量设置为提示字符串。例如：

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

Use a command-line option.使用命令行选项。 You can set the --prompt option on the command line to mysql. 您可以将命令行上的--prompt选项设置为mysql。For example:例如：

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

Use an option file.使用选项文件。 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:您可以在任何mysql选项文件的[mysql]组中设置提示选项，例如/etc/my.cnf或主目录中的.my.cnf文件。例如：

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

In this example, note that the backslashes are doubled. 在这个例子中，请注意反斜杠是加倍的。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. 如果使用选项文件中的提示选项设置提示，建议在使用特殊prompt选项时将反斜杠加倍。There is some overlap in the set of permissible prompt options and the set of special escape sequences that are recognized in option files. 允许的提示选项集和选项文件中识别的特殊转义序列集存在一些重叠。(The rules for escape sequences in option files are listed in Section 4.2.2.2, “Using Option Files”.) （第4.2.2.2节，“使用选项文件”列出了选项文件中转义序列的规则。）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. 如果使用单反斜杠，重叠可能会给您带来问题。例如，\s被解释为空格，而不是当前秒值。The following example shows how to define a prompt within an option file to include the current time in hh:mm:ss> format:以下示例显示了如何在选项文件中定义提示，以hh:mm:ss>格式包含当前时间：

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

Set the prompt interactively.以交互方式设置提示。 You can change your prompt interactively by using the prompt (or \R) command. For example:您可以使用prompt（或\R）命令以交互方式更改提示。例如：

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>