Stored Procedures
Meaning: a collection of pre-compiled SQL statement, understood as a batch statement
benefit:
1, to improve the code reusability
2, to simplify the operation
3, reducing the number of the compiler and to reduce the number of database connections and to improve the efficiency
First, create the syntax:
CREATE PROCEDURE stored procedure name (parameter list)
BEGIN
Body of the procedure (a combination method of a SQL statement)
END
note:
1, consists of three parts parameter list
Parameter name Parameter type Parameter mode
For example:
IN session name VARCHAR (20)
Parameter mode:
IN: This parameter can be used as an input, that is, the caller needs to pass this parameter value
OUT: The nibble as an output, i.e. the parameter as a return value
INOUT: This parameter either as an input and as an output, which is the need to pass both the parameter values and can return a value.
2, if only one statement in the stored procedure can be omitted BEGIN END
The end of the required weight of the stored procedure for each SQL statement must be a semicolon
The end of the stored procedure can be used to reset DELIMITER
grammar:
DELIMITER end tag
Case:
DELIMITER $
Second, the call syntax:
CALL stored procedure name (parameter list);
1, an empty parameter list
Case: five records inserted into the table admin
DELIMITER $
CREATE PROCEDURE MYP1()
BEGIN
INSERT INTO admin(username,'password')
VALUE ('join','000'),('join','111'),('join','222'),('join','333'),('join','444')；
END $
transfer
CALL myp1() $
2, create a stored procedure in mode
Case: create a stored procedure to achieve information based on the name of the goddess, god corresponding query
CREATE PROCEDURE myp2(IN beauty VARCHAR(20) )
BEGIN
SELECT bo.*
FROM boys bo
RIGHT JOIN beauty b ON bo.id = b.boyfriend_id
WHERE b.name = beautyName;
END $
transfer
CALL my2p ( 'Hsiao Ming') $
Case 2: create stored procedures, whether the user login is successful
CREATE PROCEDURE myp3(IN username VARCHAR(20), IN password VARCHAR(20))
BEGIN
DECLARE result INT DEFAULT 0; # declare and initialize variables
SELECT COUNT (*) INTO result # assignment
FROM admin
WHERE admin.username = username
AND admin.password = password;
SELECTI IF (result> 0, 'success', 'failure'); use #
END $
transfer
CALL myp3 ( 'Zhang', '8888') $
Create a stored procedure with out mode
Case 1: According to the goddess name returns the corresponding male name of God
CREATE PROCEDURE myp4(IN beautyName VARCHAR(20), OUT boyName VARCHAR(20))
BEGIN
SELECT bo.boyName INTO boyname # assignment
FROM boys bo
INNER JOIN beauty b ON bo.id = b.biyfriend_id
WHERE b.name = beautyName;
END $
transfer
#SET @ BName $ define
CALL myp4 ( 'Zhao', @bName) $ # @ bname can define also can be used directly in the use
SELECT @bName$
Case 2: According to the goddess name, returns the corresponding male name of God and Charisma
CREATE PROCEDURE my5( IN beautyName VARCHAR(20) ,OUT boyName VARCHAR(20), OUT userCP INT )
BEGIN
SELECT bo.boyName, bo.userCP INTO boyName, UserCP
FROM boys bo
INNER JOIN beauty b ON bo.id = b.biyfriend_id
WHERE b.name = beautyName;
END $
transfer
CALL my5 ( 'Zhao', @bName, @userCP) $
SELECT @BName ， @userCP$