ing
DETERMINISTC or NON-DETERMINISTIC in procedures has no effect. The default
value is NOT DETERMINISTIC. Functions are DETERMINISTIC when they always
return the same value for the same input. For example, a truncate or substring
function. Any function involving data, therefore, is always NOT DETERMINISTIC.

CONTAINS SQL/NO SQL/READS SQL DATA/MODIFIES SQL DATA
----------------------------------------------------

CONTAINS SQL, NO SQL, READS SQL DATA, and MODIFIES SQL DATA are informative
clauses that tell the server what the function does. MariaDB does not check in
any way whether the specified clause is correct. If none of these clauses are
specified, CONTAINS SQL is used by default.

MODIFIES SQL DATA means that the function contains statements that may modify
data stored in databases. This happens if the function contains statements
like DELETE, UPDATE, INSERT, REPLACE or DDL.

READS SQL DATA means that the function reads data stored in databases, but
does not modify any data. This happens if SELECT statements are used, but
there no write operations are executed.

CONTAINS SQL means that the function contains at least one SQL statement, but
it does not read or write any data stored in a database. Examples include SET
or DO.

NO SQL means nothing, because MariaDB does not currently support any language
other than SQL.

The routine_body consists of a valid SQL procedure statement. This can be a
simple statement such as SELECT or INSERT, or it can be a compound statement
written using BEGIN and END. Compound statements can contain declarations,
loops, and other control structure statements. See Programmatic and Compound
Statements for syntax details.

MariaDB allows routines to contain DDL statements, such as CREATE and DROP.
MariaDB also allows stored procedures (but not stored functions) to contain
SQL transaction statements such as COMMIT.

For additional information about statements that are not allowed in stored
routines, see Stored Routine Limitations.

Invoking stored procedure from within programs
----------------------------------------------

For information about invoking stored procedures from within programs written
in a language that has a MariaDB/MySQL interface, see CALL.

OR REPLACE
----------

If the optional OR REPLACE clause is used, it acts as a shortcut for:

DROP PROCEDURE IF EXISTS name;
CREATE PROCEDURE name ...;

with the exception that any existing privileges for the procedure are not
dropped.

sql_mode
--------

MariaDB stores the sql_mode system variable setting that is in effect at the
time a routine is created, and always executes the routine with this setting
in force, regardless of the server SQL mode in effect when the routine is
invoked.

Character Sets and Collations
-----------------------------

Procedure parameters can be declared with any character set/collation. If the
character set and collation are not specifically set, the database defaults at
the time of creation will be used. If the database defaults change at a later
stage, the stored procedure character set/collation will not be changed at the
same time; the stored procedure needs to be dropped and recreated to ensure
the same character set/collation as the database is used.

Oracle Mode
-----------

A subset of Oracle's PL/SQL language is supported in addition to the
traditional SQL/PSM-based MariaDB syntax. See Oracle mode for details on
changes when running Oracle mode.

Examples
--------

The following example shows a simple stored procedure that uses an OUT
parameter. It uses the DELIMITER command to set a new delimiter for the
duration of the process — see Delimiters in the mariadb client.

DELIMITER //

CREATE PROCEDURE simpleproc (OUT param1 INT)
 BEGIN
 SELECT COUNT(*) INTO param1 FROM t;
 END;
//

DELIMITER ;

CALL simpleproc(@a);

SELECT @a;
+------+
| @a   |
+------+
|    1 |
+------+

Character set and collation:

DELIMITER //

CREATE PROCEDURE simpleproc2 (
 OUT param1 CHAR(10) CHARACTER SET 'utf8' COLLATE 'utf8_bin'
)
 BEGIN
 SELECT CONCAT('a'),f1 INTO param1 FROM t;
 END;
//

DELIMITER ;

CREATE OR REž