MYSQL如何查看帮助文档

可以在MYSQL命令行中使用"help"命令来查看帮助文档，例如：

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. Optionally takes one argument:
          new database (db_name), new user (user_name) and password (password)
          are taken from command line if not specified.
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 one argument: the database name.
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'

也可以使用"help"命令查看特定命令的帮助文档，例如：

mysql> help select;

Name: 'SELECT'
Description:
Syntax:
SELECT
    [ALL | DISTINCT | DISTINCTROW ]
      [HIGH_PRIORITY]
      [STRAIGHT_JOIN]
      [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
      [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]
    select_expr [, select_expr ...]
    [ FROM table_references
      [WHERE where_condition]
      [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]]
      [HAVING where_condition]
      [WINDOW window_name AS (window_spec)
        [, window_name AS (window_spec)] ...]
      [ORDER BY {col_name | expr | position}
        [ASC | DESC], ...]
      [LIMIT {[offset,] row_count | row_count OFFSET offset}]
      [PROCEDURE procedure_name(argument_list)]
      [INTO OUTFILE 'file_name'
          [CHARACTER SET charset_name]
          export_options
        | INTO DUMPFILE 'file_name'
        | INTO var_name [, var_name]]
      [FOR {UPDATE | SHARE} [OF tbl_name [, tbl_name] ...] [NOWAIT | SKIP LOCKED]
       | LOCK IN SHARE MODE]]

此外，还可以通过访问MYSQL官方文档来查看更详细的帮助信息。