mysql

SYNOPSIS
mysql [options] db_name

DESCRIPTION
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().

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 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 "MYSQL LOGGING".

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, "Using Option Files".

o --help, -?

Display a help message and exit.

o --auto-rehash

Enable automatic rehashing. This option is on by default, which
readline library. Typically, the readline library is not
available on Windows.

o --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.) This option was
added in MySQL 5.5.3.

o --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.

o --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 only in the version of the mysql client
that is supplied with MySQL Cluster. It is not available in
standard MySQL Server 5.5 releases.

o --character-sets-dir=dir_name

The directory where character sets are installed. See Section 10.5,
"Character Set Configuration".

o --column-names

Write column names in results.

o --column-type-info

Display result set metadata.

o --comments, -c

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

o --compress, -C

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

o --database=db_name, -D db_name
o --debug-check

Print some debugging information when the program exits.

o --debug-info, -T

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

o --default-auth=plugin

A hint about the client-side authentication plugin to use. See
Section 6.3.6, "Pluggable Authentication".

This option was added in MySQL 5.5.7.

o --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, "Connection Character
Sets and Collations", and Section 10.5, "Character Set
Configuration".

o --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. Before MySQL 5.5.8,
file_name must be the full path name to the file. As of MySQL
5.5.8, the name is interpreted relative to the current directory if
given as a relative path name.

o --defaults-file=file_name

Use only the given option file. If the file does not exist or is
otherwise inaccessible, an error occurs. Before MySQL 5.5.8,
file_name must be the full path name to the file. As of MySQL
5.5.8, the name is interpreted relative to the current directory if
given as a relative path name.

o --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
option, long-format commands still work from the first line. See
the section called "MYSQL COMMANDS".

o --enable-cleartext-plugin

Enable the mysql_clear_password cleartext authentication plugin.
(See Section 6.5.1.5, "The Cleartext Client-Side Authentication
Plugin".) This option was added in MySQL 5.5.27.

o --execute=statement, -e statement

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

o --force, -f

Continue even if an SQL error occurs.

o --host=host_name, -h host_name

Connect to the MySQL server on the given host.

o --html, -H

Produce HTML output.

o --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,
"Server SQL Modes").

o --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.

o --line-numbers

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

o --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.

o --named-commands, -G

Do not beep when errors occur.

o --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.

o --no-named-commands, -g

Deprecated, use --disable-named-commands instead.
--no-named-commands was removed in MySQL 5.5.3.

o --no-pager

Deprecated form of --skip-pager. See the --pager option.
--no-pager was removed in MySQL 5.5.3.

o --no-tee

Deprecated form of --skip-tee. See the --tee option. --no-tee is
removed in MySQL 5.5.3.

o --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:

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

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.

o --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, "End-User Guidelines for Password
Security". You can use an option file to avoid giving the password
on the command line.

o --pipe, -W

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

o --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 6.3.6, "Pluggable
Authentication".

This option was added in MySQL 5.5.7.

o --port=port_num, -P port_num

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

o --print-defaults

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

o --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".

o --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, "Connecting to the MySQL
Server".
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)
\

o --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.

o --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.

o --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.

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.

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

o --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.

o --skip-column-names, -N

Do not write column names in results.

o --skip-line-numbers, -L

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

o --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.

o --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, "Command Options for Secure
Connections".

o --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.

o --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.

o --unbuffered, -n

Flush the buffer after each query.

o --user=user_name, -u user_name

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

o --verbose, -v

Verbose mode. Produce more output about what the program does. This
statements by terminating them with \G.

o --wait, -w

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

o --xml, -X

Produce XML output.

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. The
--set-variable format is deprecated and was removed in MySQL 5.5.3.

o connect_timeout

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

o max_allowed_packet

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

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'

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.

o 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".
executing the statement that you are entering.

o 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.

o 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, "C API Support
for Multiple Statement Execution"), and for parsing the body of
stored procedures and functions, triggers, and events (see
Section 20.1, "Defining Stored Programs").

o 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.

o ego, \G

Send the current statement to the server to be executed and display
the result using vertical format.

The nopager command works only in Unix.

o notee, \t

Disable output copying to the tee file. See the description for
tee.

o nowarning, \w

Disable display of warnings after each statement.

o 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.

o print, \p

Print the current input statement without executing it.

o 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>.

o quit, \q

Exit mysql.

o rehash, \#

Rebuild the completion hash that enables database, table, and
column name completion while you are entering statements. (See the

o system command, \! command

Execute the given command using your default command interpreter.

The system command works only in Unix.

o 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.

o use db_name, \u db_name

Use db_name as the default database.

o warnings, \W

Enable display of warnings after each statement (if there are any).

Here are a few tips about the pager command:

o 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

o 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

o 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
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 | 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) |
+-------+----------------------------+
| | 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:

o 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]> "

o 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]>

o 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]>\\_

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

o 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:

o 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.

o mysql logs each nonempty statement line individually.

o If a 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();

Controlling the History File.PP The .mysql_history file should be

o 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, "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

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>.

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.

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

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, sql_max_join_size=1000000;

See Section 5.1.5, "Server System Variables".

The SET statement has the following effects:

o 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;

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

o 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...

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,
"Controlling Automatic Reconnection Behavior".

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
For more information, please refer to the MySQL Reference Manual, which
may already be installed locally and which is also available online at
http://dev.mysql.com/doc/.

AUTHOR
Oracle Corporation (http://dev.mysql.com/).

MySQL 5.5 11/26/2016 MYSQL(1)

mysql

Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2017 Hurricane Electric. All Rights Reserved.