MySQL GRANT

MySQL GRANT

 MySQL GRANT



Summary: in this tutorial, you will learn how to use the MySQL GRANT statement to grant privileges to user accounts.

Introduction to the MySQL GRANT statement

The CREATE USER the statement creates one or more user accounts with no privileges. It means that the user accounts can log in to the MySQL Server, but cannot do anything such as selecting a database and querying data from tables.

To allow user accounts to work with database objects, you need to grant the user accounts privileges. And the GRANT statement grants a user account one or more privileges.

The following illustrates the basic syntax of the GRANT statement:

GRANT privilege [,privilege],.. ON privilege_level TO account_name;

In this syntax:

First, specify one or more privileges after the GRANT keyword. If you grant multiple privileges, you need to separate privileges by commas.

This example grants the SELECT privilege on the table employees  in the sample database to the user account bob@localhost:

GRANT SELECT ON employees TO bob@localhost;

The following example grants UPDATEDELETE, and INSERT privileges on the table employees to bob@localhost:

GRANT INSERT, UPDATE, DELETE ON employees TO bob@localhost;

Second, specify the privilege_level that determines the level to which the privileges apply.

MySQL supports the following main privilege levels:

Global privileges apply to all databases in a MySQL Server. To assign global privileges, you use the *.* syntax, for example:

GRANT SELECT ON *.* TO bob@localhost;

The account user bob@localhost can query data from all tables in all databases of the current MySQL Server.

Database privileges apply to all objects in a database. To assign database-level privileges, you use the ON database_name.* syntax, for example:

GRANT INSERT ON classicmodels.* TO bob@localhost;

In this example, bob@localhost can insert data into all tables in the classicmodels database.

Table privileges apply to all columns in a table. To assign table-level privileges, you use the ON database_name.table_name syntax, for example:

GRANT DELETE ON classicmodels.employees TO bob@localhsot;

In this example, bob@localhost can delete rows from the table employees in the database classicmodels.

If you skip the database name, MySQL uses the default database or issues an error if there is no default database.

Column privileges apply to single columns in a table.  You must specify the column or columns for each privilege, for example:

GRANT SELECT (employeeNumner,lastName, firstName,email), UPDATE(lastName) ON employees TO bob@localhost;

In this example, bob@localhost can select data from four columns employeeNumberlastNamefirstName, and email and update only the lastName column in the employees table.

Stored routine privileges apply to stored procedures and stored functions, for example:

GRANT EXECUTE ON PROCEDURE CheckCredit TO bob@localhost;

In this example, bob@localhost can execute the stored procedure CheckCredit in the current database.

Proxy user privileges allow one user to be a proxy for another. The proxy user gets all privileges of the proxied user. For example:

GRANT PROXY ON root TO alice@localhost;

In this example, alice@localhost assumes all privileges of root.

Finally, specify the account name of the user that you want to grant privileges after the TO keyword.

Notice that in order to use the GRANT the statement, you must have the GRANT OPTION privilege and the privileges that you are granting. If the read_only the the the system variable is enabled, you need to have the SUPER privilege to execute the GRANT statement.

MySQL GRANT statement examples

Typically, you use the CREATE USER statement to create a new user account first and then use the GRANT statement to grant privileges to the user.

First, create a new user called super@localhost by using the following CREATE TABLE statement:

CREATE USER super@localhost IDENTIFIED BY 'Secure1Pass!';

Second, show the privileges assigned to super@localhost user by using the SHOW GRANTS statement.

SHOW GRANTS FOR super@localhost;

The USAGE means that the super@localhost can log in to the database but has no privilege.

Third, grant all privileges in all databases in the current database server to super@localhost:

GRANT ALL ON classicmodels.* TO super@localhost;

Fourth, use the SHOW GRANTS statement again:

SHOW GRANTS FOR super@localhost;

Permissible privileges for GRANT statement

The following table illustrates all permissible privileges that you can use for the GRANT and REVOKE statement:

PrivilegeMeaningLevel
GlobalDatabaseTableColumnStored RoutineProxy
ALL [PRIVILEGES]Grant all privileges at specified access level except GRANT OPTION
ALTERAllow user to use of ALTER TABLEstatementXXX
ALTER ROUTINEAllow users to alter and drop stored procedures or stored functions.XXX
CREATEAllow users to create databases and tablesXXX
CREATE ROUTINEAllow user to create stored procedures and stored functionsXX
CREATE TABLESPACEAllow users to create, alter or drop tablespaces and log file groupsX
CREATE TEMPORARY TABLESAllow user to create a temporary table by using CREATE TEMPORARY TABLE statementXX
CREATE USERAllow users to use the CREATE USER, DROP USER, RENAME USER, and REVOKE ALL PRIVILEGES statements.X
CREATE VIEWAllow users to create or modify the view.XXX
DELETEAllow users to use DELETE statementXXX
DROPAllow user to drop database, table, and viewXXX
EVENTEnable use of events for the Event Scheduler.XX
EXECUTEAllow user to execute stored routinesXXX
FILEAllow users to read any file in the database directory.X
GRANT OPTIONAllow users to have privileges to grant or revoke privileges from other accounts.XXXXX
INDEXAllow users to create or drop indexes.XXX
INSERTAllow users to use the INSERT statementXXXX
LOCK TABLESAllow users to use LOCK TABLES on tables for which you have the SELECT privilegeXX
PROCESSAllow user to see all processes with SHOW PROCESSLIST statement.X
PROXYEnable user proxying.
REFERENCESAllow user to create a foreign keyXXXX
RELOADAllow users to use FLUSH statementX
REPLICATION CLIENTAllow user to query to see where master or slave servers areX
REPLICATION SLAVEAllow the user to use replicate slaves to read binary log events from the master.X
SELECTAllow users to use SELECT statementXXXX
SHOW DATABASESAllow user to show all databasesX
SHOW VIEWAllow users to use SHOW CREATE VIEW statementXXX
SHUTDOWNAllow user to use Mysqladmin shutdown commandX
SUPERAllow user to use other administrative operations such as CHANGE MASTER TOKILLPURGE BINARY LOGSSET GLOBAL, and mysqladmin commandX
TRIGGERAllow users to use TRIGGER operations.XXX
UPDATEAllow users to use the UPDATE statementXXXX
USAGEEquivalent to “no privileges”

In this tutorial, you have learned how to use the MySQL GRANT statement to grant privileges to a user.

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