Mysql stored procedure instance

**Introduction to Stored Procedures** Stored procedures are a powerful feature in database systems that allow you to encapsulate a set of SQL statements into a single unit. Unlike regular SQL statements, which are compiled and executed at runtime, stored procedures are precompiled and stored directly in the database. This means they can be called by specifying their name and providing any required parameters, making them efficient and reusable. A stored procedure is essentially a programmable function that resides in the database. It can include not only SQL statements but also control structures such as loops, conditionals, and error handling. These features make stored procedures ideal for performing complex operations across different applications or platforms. They act like methods in object-oriented programming, enabling better control over data access and manipulation. Before MySQL 5.0, the database lacked support for stored procedures, which limited its use in more sophisticated applications. However, with the release of MySQL 5.0, this feature was introduced, significantly improving performance and flexibility in database development. Stored procedures offer several advantages: 1. **Enhanced Flexibility**: They allow for complex logic through flow control statements, making it easier to handle intricate tasks. 2. **Reusability**: Once created, a stored procedure can be called multiple times without rewriting the SQL code, reducing redundancy. 3. **Faster Execution**: Since stored procedures are precompiled, they execute faster than batch SQL statements, especially when used frequently. 4. **Reduced Network Traffic**: Instead of sending multiple SQL commands over the network, only the procedure call is transmitted, minimizing load. 5. **Improved Security**: Database administrators can restrict access to specific stored procedures, ensuring data integrity and protection against unauthorized access. **Creating a Stored Procedure in MySQL** The basic syntax for creating a stored procedure in MySQL is as follows: ```sql CREATE PROCEDURE procedure_name ([IN|OUT|INOUT] parameter_name data_type, ...) BEGIN -- SQL statements END; ``` For example, here’s how to create a simple stored procedure: ```sql DELIMITER // CREATE PROCEDURE proc1(OUT s INT) BEGIN SELECT COUNT(*) INTO s FROM user; END // DELIMITER ; ``` **Notes on Creating Stored Procedures:** - The `DELIMITER` command is used to change the statement delimiter from `;` to something else (like `//`) so that the entire procedure can be processed as a single block. - Parameters can be of three types: `IN`, `OUT`, and `INOUT`. - `IN`: A value passed to the procedure. - `OUT`: A value returned from the procedure. - `INOUT`: A value that can both be passed and modified within the procedure. **Examples of Parameter Usage:** **1. IN Parameter Example:** ```sql DELIMITER // CREATE PROCEDURE demo_in_parameter(IN p_in INT) BEGIN SELECT p_in; SET p_in = 2; SELECT p_in; END // DELIMITER ; ``` When called, the input value remains unchanged outside the procedure. **2. OUT Parameter Example:** ```sql DELIMITER // CREATE PROCEDURE demo_out_parameter(OUT p_out INT) BEGIN SELECT p_out; SET p_out = 2; SELECT p_out; END // DELIMITER ; ``` This procedure modifies the output parameter and returns the updated value. **3. INOUT Parameter Example:** ```sql DELIMITER // CREATE PROCEDURE demo_inout_parameter(INOUT p_inout INT) BEGIN SELECT p_inout; SET p_inout = 2; SELECT p_inout; END // DELIMITER ; ``` This type of parameter allows both input and output, making it versatile for various use cases. By using stored procedures, developers can streamline database interactions, improve performance, and enhance application security. Whether you're building a small web application or a large enterprise system, understanding and utilizing stored procedures can greatly benefit your database design and management.

Glass Fiber Series Wire

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Glass Fiber Copper Wire

Name	Insulation Glass Fiber Winding Wire
Conductor	Copper
Dimension(mm)	Round: 1.0 ~ 7.0
	Rectangular: Thickness(a): 1.0 ~ 10.0 Width(b): 3.0 ~ 35
Insulation Material Type	Fiber Glass
Insulation Thickness	Singer, double or according to your requirement
Standard	IEC; ISO9000; ISO9001; IATF16949
Packing	100kg ~120kg ply-wood spool (250*500)
Application	Oil-immersed transformer windings, medium and large electrical motor and power substations, etc.

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Name	Insulation Glass Fiber Winding Wire
Conductor	Aluminum
Dimension(mm)	Rectangular: Thickness(a): 1.0 ~10.0 Width(b): 3.0 ~ 35
Insulation Material Type	Fiber Glass
Insulation Thickness	Single, double or according to your requirement
Standard	IEC; ISO9000; ISO9001; IATF16949
Packing	50kg~150kg ply-wood spool (250*500/ 250*550/ 250*600)
Application	Oil-immersed transformer windings, medium and large electrical motor and power substations, etc.

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