Function
Function, in computer programming language context, a set of instructions which takes some input and performs certain tasks. In SQL, a function returns a value.
Procedure
Procedure, as well, is a set of instructions which takes input and performs certain task. In SQL, procedure does not return a value. In java, procedure and functions are same and also called sub-routines.
Following are the important differences between SQL Function and SQL Procedure.
| Sr. No. | Key | Function | Procedure |
|---|---|---|---|
| 1 | Definition | A function is used to calculate result using given inputs. | A procedure is used to perform certain task in order. |
| 2 | Call | A function can be called by a procedure. | A procedure cannot be called by a function. |
| 3 | DML | DML statments cannot be executed within a function. | DML statements can be executed within a procedure. |
| 4 | SQL, Query | A function can be called within a query. | A procedure cannot be called within a query. |
| 5 | SQL, Call | Whenever a function is called, it is first compiled before being called. | A procedure is compiled once and can be called multiple times without being compiled. |
| 6 | SQL, Return | A function returns a value and control to calling function or code. | A procedure returns the control but not any value to calling function or code. |
| 7 | try-catch | A function has no support for try-catch | A procedure has support for try-catch blocks. |
| 8 | SELECT | A select statement can have a function call. | A select statemnt can't have a procedure call. |
| 9 | Explicit Transaction Handling | A function can not have explicit transaction handling. | A procedure can use explicit transaction handling. |