What are stored procedures in a database?

Stored procedures are precompiled SQL statements stored in a database that can be executed repeatedly.

Stored procedures are a key feature of relational database management systems (RDBMS). They are essentially blocks of code written in SQL that are stored directly in the database. Once a stored procedure is in the database, it can be run or 'called' by applications, triggers, or other stored procedures. This allows for complex operations to be performed directly on the database server, reducing network traffic and improving performance.

Stored procedures are precompiled, meaning the database server compiles the SQL code into a more efficient format that can be run faster. This is particularly beneficial when the stored procedure is run repeatedly, as the server can reuse the precompiled code, saving the time it would take to compile the code each time it is run.

Stored procedures also provide a level of abstraction between the database and the application. The application does not need to know the specifics of the SQL code or the database schema, it just needs to know the name of the stored procedure and the parameters it requires. This can make applications easier to develop and maintain, as changes to the database schema or the SQL code can be made without affecting the application.

Furthermore, stored procedures can help improve security. By using stored procedures, you can limit the types of operations that can be performed on the database, and control who can perform them. For example, you could create a stored procedure that allows a user to update their own details, but not those of other users. This can help to prevent SQL injection attacks, where malicious SQL code is inserted into a query in an attempt to gain unauthorised access to data.

In summary, stored procedures are a powerful tool in database management, offering benefits in performance, development efficiency, and security. They are an essential concept for any student studying computer science, particularly those focusing on database management and development.