Understand the modification of Oracle stored procedures

Oracle is one of the world's largest database companies, and its database management system is one of the most widely used databases. In the Oracle database, a stored procedure is an executable program that consists of a series of PL/SQL or SQL statements with a definite name and can be executed multiple times so that these statements can be reused. This article will take you through the modification of Oracle stored procedures.

For stored procedures in Oracle database, when the requirements of the database change or developers need to update it, it is crucial to modify the stored procedures. The steps to modify stored procedures in Oracle database will be introduced in detail below.

Step one: Back up the stored procedure

Before modifying the stored procedure, first back up the original stored procedure. Once there is a problem modifying the stored procedure, backup can help you recover the data. Specifically, you can back up the stored procedure through the following steps:

1. Open the Oracle SQL*Plus command interface and connect to the corresponding instance.

2. Use the SHOW CREATE PROCEDURE statement to obtain the source code of the stored procedure.

3. Copy the obtained stored procedure source code to a text file and store it as a backup file.

Step 2: Modify the stored procedure

Modifying the stored procedure can be done in two ways: one is to use the CREATE OR REPLACE PROCEDURE statement, under which the code of the stored procedure is added or changed. ;The other is to use the ALTER PROCEDURE statement to update only part of the code of the stored procedure. The specific method is as follows:

Use the CREATE OR REPLACE PROCEDURE statement to modify the stored procedure:

1. Open the Oracle SQL*Plus command interface and connect to the corresponding instance.

2. Use the SHOW CREATE PROCEDURE statement to obtain the source code of the original stored procedure.

3. Use the CREATE OR REPLACE PROCEDURE statement to modify the part you need to update.

For example, you need to modify the SELECT statement in a stored procedure into an INSERT statement.

Original stored procedure:

CREATE PROCEDURE get_emp_salary
IS
BEGIN
SELECT salary FROM employee WHERE employee_id = 100;
END;

Modified stored procedure:

CREATE OR REPLACE PROCEDURE get_emp_salary
IS
BEGIN
INSERT INTO new_employee (employee_id, salary) values ​​(100, 5000);
END;

Use the ALTER PROCEDURE statement to modify the stored procedure:

1. Open the Oracle SQL*Plus command interface and connect to the corresponding instance.

2. Use the SHOW CREATE PROCEDURE statement to obtain the source code of the stored procedure.

3. Use the ALTER PROCEDURE statement to modify part of the code of the stored procedure.

For example, you need to modify a line of statements in the stored procedure:

ALTER PROCEDURE get_emp_salary
IS
BEGIN
UPDATE employee SET salary = 5000 WHERE employee_id = 100;
END;

Step 3: Test the modified stored procedure

After modifying the stored procedure, you need to test it to confirm that the result is correct. You can use the Oracle SQL*Plus command interface to test the modified stored procedure, for example:

EXEC get_emp_salary;

If the stored procedure runs successfully, you will see the results you expect.

Summary:

In Oracle database, stored procedure modification is a very important operation. To ensure data security and recoverability, be sure to back up the original stored procedure before modifying it. When modifying a stored procedure, you can use the CREATE OR REPLACE PROCEDURE statement or the ALTER PROCEDURE statement. Finally, remember to test your modified stored procedure to make sure it runs successfully.

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