Functions vs Stored Procedures

 Key Differences: Function vs. Procedure

Parameter	Function	Procedure
Return Value	Must return a single value (scalar or table) using a RETURN statement.	May or may not return a value. Values can be returned using OUT or INOUT parameters.
Usage in SQL	Can be called directly within SQL statements (like SELECT, WHERE, HAVING, or JOIN clauses).	Cannot be called directly within a SELECT or DML statement. Must be executed using the EXEC or CALL statement.
DML Statements	Cannot perform DML operations (e.g., INSERT, UPDATE, DELETE) on permanent database tables.	Can perform DML operations to modify the database state.
Error Handling	Does not support TRY...CATCH blocks for structured exception handling.	Supports TRY...CATCH blocks for robust error handling.
Transaction Control	Cannot manage transactions (e.g., COMMIT, ROLLBACK).	Can manage transactions explicitly.
Calling	Can be called from a stored procedure.	Cannot be called from a function in most DBMSs.
Temporary Tables	Generally only allows table variables, not temporary tables (e.g., #temp).	Allows the use of both table variables and temporary tables