But in the actual operation of the database, there is often a complete operation that requires multiple SQL statements to process multiple tables to complete.
For example, in order to confirm whether a student can graduate, the student profile table, grade table and comprehensive table need to be queried at the same time. In this case, multiple SQL statements need to be used to complete this processing requirement for several data tables. Stored procedures can accomplish this database operation efficiently.
Stored procedures are an important function of database storage, but MySQL did not support stored procedures before 5.0, which greatly reduced the application of MySQL. Fortunately, MySQL 5.0 has finally begun to support stored procedures, which can greatly improve the processing speed of the database and also improve the flexibility of database programming.
A stored procedure is a set of SQL statements designed to accomplish a specific function. The purpose of using stored procedures is to pre-write common or complex work with SQL statements and store them with a specified name. This procedure is compiled and optimized and stored in the database server, so it is called a stored procedure. When you need the database to provide the same service as the defined stored procedure in the future, you only need to call "CALL stored procedure name" to automatically complete it.
SQL statements commonly used to operate the database need to be compiled first and then executed. Stored procedures take another approach to executing SQL statements.
A stored procedure is a programmable function that is created and saved in the database. It generally consists of SQL statements and some special control structures. Stored procedures are particularly suitable when you want to perform the same specific function on different applications or platforms.
Stored procedures usually have the following advantages:
1) Encapsulation
After the stored procedure is created, it can be used in the program It can be called multiple times without having to rewrite the SQL statement of the stored procedure, and database professionals can modify the stored procedure at any time without affecting the source code of the application that calls it.
2) Can enhance the function and flexibility of SQL statements
Stored procedures can be written using flow control statements, which have strong flexibility and can complete complex judgments and more complex operations.
3) Can reduce network traffic
Because the stored procedure is run on the server side and the execution speed is fast, when the stored procedure is called on the client computer, Only the call statement is transmitted over the network, thus reducing network load.
4) High performance
After the stored procedure is executed once, the generated binary code resides in the buffer. In subsequent calls, it only needs to be retrieved from the buffer Just execute the binary code in the system, thus improving the efficiency and performance of the system.
5) Improve database security and data integrity
All database operations can be completed using stored procedures, and access to database information can be controlled programmatically permissions.
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