This manual uses certain typographical conventions:本手册使用某些排版惯例：

When commands are shown that are meant to be executed from within a particular program, the prompt shown preceding the command indicates which command to use. 当显示要在特定程序中执行的命令时，命令前面显示的提示符指示要使用哪个命令。For example, shell> indicates a command that you execute from your login shell, root-shell> is similar but should be executed as root, and mysql> indicates a statement that you execute from the mysql client program:

shell> type a shell command here
root-shell> type a shell command as root here
mysql> type a mysql statement here

In some areas different systems may be distinguished from each other to show that commands should be executed in two different environments. 在某些领域，不同的系统可能会相互区别，以表明命令应该在两个不同的环境中执行。For example, while working with replication the commands might be prefixed with source and replica:例如，在使用复制时，命令的前缀可能是source和replica：

source> type a mysql command on the replication source here
replica> type a mysql command on the replica here

The “shell” is your command interpreter. On Unix, this is typically a program such as sh, csh, or bash. On Windows, the equivalent program is command.com or cmd.exe, typically run in a console window.

When you enter a command or statement shown in an example, do not type the prompt shown in the example.输入示例中所示的命令或语句时，不要键入示例中所示的提示。

Database, table, and column names must often be substituted into statements. 数据库、表和列名通常必须替换为语句。To indicate that such substitution is necessary, this manual uses db_name, tbl_name, and col_name. For example, you might see a statement like this:

mysql> SELECT col_name FROM db_name.tbl_name;

This means that if you were to enter a similar statement, you would supply your own database, table, and column names, perhaps like this:这意味着，如果要输入类似的语句，则需要提供自己的数据库、表和列名，可能如下所示：

mysql> SELECT author_name FROM biblio_db.author_list;

SQL keywords are not case-sensitive and may be written in any lettercase. This manual uses uppercase.

In syntax descriptions, square brackets (“[” and “]”) indicate optional words or clauses. For example, in the following statement, IF EXISTS is optional:

DROP TABLE [IF EXISTS] tbl_name

When a syntax element consists of a number of alternatives, the alternatives are separated by vertical bars (“|”). When one member from a set of choices may be chosen, the alternatives are listed within square brackets (“[” and “]”):

TRIM([[BOTH | LEADING | TRAILING] [remstr] FROM] str)

When one member from a set of choices must be chosen, the alternatives are listed within braces (“{” and “}”):

{DESCRIBE | DESC} tbl_name [col_name | wild]

An ellipsis (...) indicates the omission of a section of a statement, typically to provide a shorter version of more complex syntax. For example, SELECT ... INTO OUTFILE is shorthand for the form of SELECT statement that has an INTO OUTFILE clause following other parts of the statement.

An ellipsis can also indicate that the preceding syntax element of a statement may be repeated. In the following example, multiple reset_option values may be given, with each of those after the first preceded by commas:

RESET reset_option [,reset_option] ...

Commands for setting shell variables are shown using Bourne shell syntax. For example, the sequence to set the CC environment variable and run the configure command looks like this in Bourne shell syntax:

shell> CC=gcc ./configure

If you are using csh or tcsh, you must issue commands somewhat differently:

shell> setenv CC gcc
shell> ./configure

The Reference Manual source files are written in DocBook XML format. 参考手册源文件是以DocBook XML格式编写的。The HTML version and other formats are produced automatically, primarily using the DocBook XSL stylesheets. HTML版本和其他格式是自动生成的，主要使用DocBook XSL样式表。For information about DocBook, see 有关DocBook的信息，请参阅http://docbook.org/

This manual was originally written by David Axmark and Michael “Monty” Widenius. 本手册最初由David Axmark和Michael“Monty”Widenius编写。It is maintained by the MySQL Documentation Team, consisting of Chris Cole, Paul DuBois, Margaret Fisher, Edward Gilmore, Stefan Hinz, David Moss, Philip Olson, Daniel Price, Daniel So, and Jon Stephens.它由MySQL文档团队维护，该团队由Chris Cole、Paul DuBois、Margaret Fisher、Edward Gilmore、Stefan Hinz、David Moss、Philip Olson、Daniel Price、Daniel So和Jon Stephens组成。