You can create MySQL accounts in two ways:
By using statements intended for creating accounts, such as
CREATE USER
orGRANT
. These statements cause the server to make appropriate modifications to the grant tables.By manipulating the MySQL grant tables directly with statements such as
INSERT
,UPDATE
, orDELETE
.
The preferred method is to use account-creation statements because
they are more concise and less error-prone than manipulating the
grant tables directly. CREATE USER
and GRANT
are described in
Section 12.4.1, “Account Management Statements”.
Another option for creating accounts is to use one of several
available third-party programs that offer capabilities for MySQL
account administration. phpMyAdmin
is one such
program.
The following examples show how to use the
mysql client program to set up new accounts.
These examples assume that privileges have been set up according
to the defaults described in Section 2.12.2, “Securing the Initial MySQL Accounts”.
This means that to make changes, you must connect to the MySQL
server as the MySQL root
user, and the
root
account must have the
INSERT
privilege for the
mysql
database and the
RELOAD
administrative privilege.
As noted in the examples where appropriate, some of the statements
will fail if the server's SQL mode has been set to enable certain
restrictions. In particular, strict mode
(STRICT_TRANS_TABLES
,
STRICT_ALL_TABLES
) and
NO_AUTO_CREATE_USER
will prevent
the server from accepting some of the statements. Workarounds are
indicated for these cases. For more information about SQL modes
and their effect on grant table manipulation, see
Section 5.1.7, “Server SQL Modes”, and Section 12.4.1.3, “GRANT
Syntax”.
First, use the mysql program to connect to the
server as the MySQL root
user:
shell> mysql --user=root mysql
If you have assigned a password to the root
account, you will also need to supply a
--password
or -p
option, both
for this mysql command and for those later in
this section.
After connecting to the server as root
, you can
add new accounts. The following statements use
GRANT
to set up four new accounts:
mysql>CREATE USER 'monty'@'localhost' IDENTIFIED BY 'some_pass';
mysql>GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost'
->WITH GRANT OPTION;
mysql>CREATE USER 'monty'@'%' IDENTIFIED BY 'some_pass';
mysql>GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%'
->WITH GRANT OPTION;
mysql>CREATE USER 'admin'@'localhost';
mysql>GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
mysql>CREATE USER 'dummy'@'localhost';
The accounts created by these statements have the following properties:
Two of the accounts have a user name of
monty
and a password ofsome_pass
. Both accounts are superuser accounts with full privileges to do anything. The'monty'@'localhost'
account can be used only when connecting from the local host. The'monty'@'%'
account uses the'%'
wildcard for the host part, so it can be used to connect from any host.It is necessary to have both accounts for
monty
to be able to connect from anywhere asmonty
. Without thelocalhost
account, the anonymous-user account forlocalhost
that is created by mysql_install_db would take precedence whenmonty
connects from the local host. As a result,monty
would be treated as an anonymous user. The reason for this is that the anonymous-user account has a more specificHost
column value than the'monty'@'%'
account and thus comes earlier in theuser
table sort order. (user
table sorting is discussed in Section 5.4.4, “Access Control, Stage 1: Connection Verification”.)The
'admin'@'localhost'
account has no password. This account can be used only byadmin
to connect from the local host. It is granted theRELOAD
andPROCESS
administrative privileges. These privileges enable theadmin
user to execute the mysqladmin reload, mysqladmin refresh, and mysqladmin flush-xxx
commands, as well as mysqladmin processlist . No privileges are granted for accessing any databases. You could add such privileges later by issuing otherGRANT
statements.The
'dummy'@'localhost'
account has no password. This account can be used only to connect from the local host. No privileges are granted. It is assumed that you will grant specific privileges to the account later.
The statements that create accounts with no password will fail if
the NO_AUTO_CREATE_USER
SQL mode
is enabled. To deal with this, use an IDENTIFIED
BY
clause that specifies a nonempty password.
To check the privileges for an account, use
SHOW GRANTS
:
mysql> SHOW GRANTS FOR 'admin'@'localhost';
+-----------------------------------------------------+
| Grants for admin@localhost |
+-----------------------------------------------------+
| GRANT RELOAD, PROCESS ON *.* TO 'admin'@'localhost' |
+-----------------------------------------------------+
As an alternative to CREATE USER
and GRANT
, you can create the same
accounts directly by issuing INSERT
statements and then telling the server to reload the grant tables
using FLUSH
PRIVILEGES
:
shell>mysql --user=root mysql
mysql>INSERT INTO user
->VALUES('localhost','monty',PASSWORD('some_pass'),
->'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y');
mysql>INSERT INTO user
->VALUES('%','monty',PASSWORD('some_pass'),
->'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y',
->'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y',
->'','','','',0,0,0,0);
mysql>INSERT INTO user SET Host='localhost',User='admin',
->Reload_priv='Y', Process_priv='Y';
mysql>INSERT INTO user (Host,User,Password)
->VALUES('localhost','dummy','');
mysql>FLUSH PRIVILEGES;
When you create accounts with
INSERT
, it is necessary to use
FLUSH PRIVILEGES
to tell the server to reload the grant tables. Otherwise, the
changes go unnoticed until you restart the server. With
CREATE USER
,
FLUSH PRIVILEGES
is unnecessary.
The reason for using the PASSWORD()
function with INSERT
is to encrypt
the password. The CREATE USER
statement encrypts the password for you, so
PASSWORD()
is unnecessary.
The 'Y'
values enable privileges for the
accounts. Depending on your MySQL version, you may have to use a
different number of 'Y'
values in the first two
INSERT
statements. The
INSERT
statement for the
admin
account employs the more readable
extended INSERT
syntax using
SET
.
In the INSERT
statement for the
dummy
account, only the
Host
, User
, and
Password
columns in the user
table row are assigned values. None of the privilege columns are
set explicitly, so MySQL assigns them all the default value of
'N'
. This is equivalent to what
CREATE USER
does.
If strict SQL mode is enabled, all columns that have no default
value must have a value specified. In this case,
INSERT
statements must explicitly
specify values for the ssl_cipher
,
x509_issuer
, and
x509_subject
columns.
To set up a superuser account, it is necessary only to insert a
user
table row with all privilege columns set
to 'Y'
. The user
table
privileges are global, so no entries in any of the other grant
tables are needed.
The next examples create three accounts and give them access to
specific databases. Each of them has a user name of
custom
and password of
obscure
.
To create the accounts with CREATE
USER
and GRANT
, use the
following statements:
shell>mysql --user=root mysql
mysql>CREATE USER 'custom'@'localhost' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
->ON bankaccount.*
->TO 'custom'@'localhost';
mysql>CREATE USER 'custom'@'host47.example.com' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
->ON expenses.*
->TO 'custom'@'host47.example.com';
mysql>CREATE USER 'custom'@'server.domain' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
->ON customer.*
->TO 'custom'@'server.domain';
The three accounts can be used as follows:
The first account can access the
bankaccount
database, but only from the local host.The second account can access the
expenses
database, but only from the hosthost47.example.com
.The third account can access the
customer
database, but only from the hostserver.domain
.
To set up the custom
accounts without
GRANT
, use
INSERT
statements as follows to
modify the grant tables directly:
shell>mysql --user=root mysql
mysql>INSERT INTO user (Host,User,Password)
->VALUES('localhost','custom',PASSWORD('obscure'));
mysql>INSERT INTO user (Host,User,Password)
->VALUES('host47.example.com','custom',PASSWORD('obscure'));
mysql>INSERT INTO user (Host,User,Password)
->VALUES('server.domain','custom',PASSWORD('obscure'));
mysql>INSERT INTO db
->(Host,Db,User,Select_priv,Insert_priv,
->Update_priv,Delete_priv,Create_priv,Drop_priv)
->VALUES('localhost','bankaccount','custom',
->'Y','Y','Y','Y','Y','Y');
mysql>INSERT INTO db
->(Host,Db,User,Select_priv,Insert_priv,
->Update_priv,Delete_priv,Create_priv,Drop_priv)
->VALUES('host47.example.com','expenses','custom',
->'Y','Y','Y','Y','Y','Y');
mysql>INSERT INTO db
->(Host,Db,User,Select_priv,Insert_priv,
->Update_priv,Delete_priv,Create_priv,Drop_priv)
->VALUES('server.domain','customer','custom',
->'Y','Y','Y','Y','Y','Y');
mysql>FLUSH PRIVILEGES;
The first three INSERT
statements
add user
table entries that permit the user
custom
to connect from the various hosts with
the given password, but grant no global privileges (all privileges
are set to the default value of 'N'
). The next
three INSERT
statements add
db
table entries that grant privileges to
custom
for the bankaccount
,
expenses
, and customer
databases, but only when accessed from the proper hosts. As usual
when you modify the grant tables directly, you must tell the
server to reload them with
FLUSH PRIVILEGES
so that the privilege changes take effect.
To create a user who has access from all machines in a given
domain (for example, mydomain.com
), you can use
the “%
” wildcard character in the
host part of the account name:
mysql> CREATE USER 'myname'@'%.mydomain.com' IDENTIFIED BY 'mypass';
To do the same thing by modifying the grant tables directly, do this:
mysql>INSERT INTO user (Host,User,Password,...)
->VALUES('%.mydomain.com','myname',PASSWORD('mypass'),...);
mysql>FLUSH PRIVILEGES;