44 Stored Procedure vs Function in SQL Server | Key Differences Explained
Stored Procedure vs Function in SQL Server
Basic Difference
👉 Stored Procedure → Executes a set of SQL statements
👉 Function → Returns a value (or table)
1️⃣ Return Type
👉 Stored Procedure
Can return multiple values (result sets, output params)
👉 Function
Must return a single value or table
2️⃣ Usage in Queries
👉 Stored Procedure
❌ Cannot be used inside SELECT
👉 Function
✔ Can be used inside SELECT
Example
-- Function
SELECT dbo.CalculateBonus(Salary)
FROM Employees;
-- Stored Procedure (Not Allowed)
SELECT dbo.GetEmployees;
3️⃣ Parameters
👉 Stored Procedure
✔ Input + Output parameters allowed
👉 Function
✔ Only input parameters (no output params)
4️⃣ Data Modification
👉 Stored Procedure
✔ Can INSERT, UPDATE, DELETE
👉 Function
❌ Cannot modify database state
5️⃣ Error Handling
👉 Stored Procedure
✔ Supports TRY...CATCH
👉 Function
❌ No TRY...CATCH support
6️⃣ Transactions
👉 Stored Procedure
✔ Can use transactions
👉 Function
❌ Cannot use transactions
7️⃣ Execution
👉 Stored Procedure
EXEC GetEmployees
👉 Function
SELECT dbo.GetEmployeesByDepartment(1)
8️⃣ Performance (Important)
👉 Stored Procedure
✔ Faster for complex operations
✔ Better for bulk data processing
👉 Function
⚠️ Scalar functions can be slower (row-by-row execution)
✔ Inline table functions perform better
9️⃣ Use Case
👉 Stored Procedure
✔ Business logic
✔ Data manipulation
✔ Complex workflows
👉 Function
✔ Calculations
✔ Reusable logic inside queries