Stored Procedures and Views are both database objects in SQL, but they serve different purposes and have distinct characteristics:
Stored Procedures:
1. Definition: A stored procedure is a named collection of SQL statements and procedural logic that is stored in the database. It can accept parameters, perform complex operations, and return results.
2. Functionality: Stored procedures are primarily used to encapsulate and execute a series of SQL statements as a single unit. They can perform data manipulation, data retrieval, data modification, and other tasks.
3. Reusability: Stored procedures are reusable and can be called from different parts of an application or other database objects. They provide modularity, code centralization, and can improve performance by reducing network traffic.
4. Security: Stored procedures can enforce security by allowing or restricting access to underlying tables and data. They can be granted permissions independently from the underlying tables, providing an additional layer of security.
5. Performance: Stored procedures can improve performance by reducing the round-trips between the application and the database server. Once compiled and stored in the database, they can be executed more efficiently.
6. Flexibility: Stored procedures can include control flow logic, looping, and branching, which allows for complex business logic implementation within the database.
Views:
1. Definition: A view is a virtual table created from the result of a stored query. It is a named and stored SQL query that can be treated as a table in subsequent queries.
2. Functionality: Views are primarily used to simplify complex queries, provide a customized and filtered view of data, and abstract the underlying data structure. They can join multiple tables, aggregate data, or apply filters.
3. Read-Only: Views are read-only by default, meaning they cannot be used to directly modify the underlying data. However, they can be used in conjunction with other SQL statements to modify data indirectly.
4. Abstraction: Views can hide the underlying complexity of data models and present a simplified and consistent view to end users or applications. They provide a layer of abstraction and can be used to enforce data access rules and security.
5. Simplification: Views can simplify query syntax by providing pre-defined joins, filters, and aggregations. They can be used to encapsulate complex SQL logic and make it easier to query specific subsets of data.
6. Dependency: Views are dependent on the underlying tables or other views. If the structure or data of the underlying objects change, the view will reflect those changes automatically.
In summary, stored procedures are used to encapsulate and execute SQL statements and procedural logic, while views are used to provide a simplified, virtual representation of data based on stored queries. Stored procedures focus on functionality, reusability, and performance optimization, while views focus on abstraction, simplification, and providing a customizable view of data.