Stored procedures are essential components in database development, enabling complex business logic to be executed directly on the database server. In SAP HANA, stored procedures provide a powerful way to encapsulate SQL code and procedural logic, allowing for efficient and reusable data processing within the database.
This article introduces the concept of stored procedures in SAP HANA, guiding you through their creation and usage.
A stored procedure is a precompiled collection of SQL statements and procedural logic stored in the database. They allow you to:
SAP HANA supports stored procedures written in SQLScript, a procedural extension of SQL optimized for SAP HANA.
Access SAP HANA Studio or SAP HANA Database Explorer and open the SQL console connected to your database.
Here’s a simple example of creating a stored procedure that retrieves employee details from an EMPLOYEES table based on a department input parameter:
CREATE PROCEDURE GET_EMPLOYEES_BY_DEPT (IN DEPT_NAME NVARCHAR(50))
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER
AS
BEGIN
SELECT EMPLOYEE_ID, FIRST_NAME, LAST_NAME, SALARY
FROM EMPLOYEES
WHERE DEPARTMENT = DEPT_NAME;
END;
Explanation:
IN DEPT_NAME NVARCHAR(50): Input parameter to filter employees by department.LANGUAGE SQLSCRIPT: Specifies the procedure language.SQL SECURITY INVOKER: Executes the procedure with the caller's privileges.BEGIN ... END block contains the SQL logic.Run the above script in the SQL console. If successful, the procedure is created and stored in the database.
You can execute the stored procedure using the CALL statement:
CALL GET_EMPLOYEES_BY_DEPT('Sales');
This command retrieves all employees from the Sales department.
Stored procedures in SAP HANA can return multiple result sets or output parameters. For example:
CREATE PROCEDURE GET_EMPLOYEE_SALARY (IN EMP_ID INT, OUT SALARY DECIMAL(15,2))
LANGUAGE SQLSCRIPT
AS
BEGIN
SELECT SALARY INTO SALARY FROM EMPLOYEES WHERE EMPLOYEE_ID = EMP_ID;
END;
You can then call this procedure and capture the output:
DECLARE OUT_SALARY DECIMAL(15,2);
CALL GET_EMPLOYEE_SALARY(1001, OUT_SALARY);
SELECT :OUT_SALARY FROM DUMMY;
Stored procedures in SAP HANA are powerful tools for embedding complex business logic within the database. By using SQLScript, SAP professionals can create efficient, reusable, and secure data processing routines that enhance application performance and maintain consistency.
Learning to create and manage stored procedures is a key skill for SAP HANA developers and database administrators aiming to leverage the full capabilities of the SAP HANA platform.