What is the difference between a stored procedure and a function in SQL Server?

Stored Procedure vs. Function in SQL Server - Understanding the Differences

When comparing stored procedures and functions in SQL Server, it is important to recognize the key distinctions between the two. The focus keyword of this discussion, "stored procedure," refers to a precompiled collection of SQL statements that are stored in the database for later use.

Stored Procedure:

• A stored procedure is a set of SQL statements that perform a specific task or a series of tasks.
• Stored procedures can contain input and output parameters for flexibility and reusability.
• They can execute multiple SQL queries and statements within a single transaction.
• Stored procedures can be called from within other SQL queries or applications.
• They are ideal for complex business logic and extensive data manipulation.

Function:

• A function is a SQL module that returns a single value based on the input parameters.
• Functions are deterministic, meaning they always return the same output for a given input.
• Functions cannot change the database state and are primarily used for computations.
• They can be part of SQL queries, calculations, or as part of other functions or stored procedures.

In summary, while both stored procedures and functions serve important roles in SQL Server, stored procedures are used for executing reusable blocks of code and transactions, while functions focus on computations and returning specific values based on input parameters.

By understanding the differences between stored procedures and functions, you can utilize them effectively in your SQL Server database management strategies.