Oracle database is one of the most popular relational databases in the world. It supports various features such as stored procedures, triggers and functions, which can perform data operations and business logic more efficiently. This article explains how to call stored procedures in an Oracle database.
What is a stored procedure?
A stored procedure is an executable program object in the database. It can receive parameters, execute a series of SQL statements, run business logic and return results during execution. Stored procedures are usually used for repetitive data processing operations and complex data manipulation processes. In Oracle database, stored procedures are divided into two types: procedures and functions.
The procedure has no return value. It can be called like a subroutine and can perform a series of SQL statement operations.
Function has a return value. It can be called like a function, and can perform a series of SQL statement operations and finally return a result value.
How to create a stored procedure?
In Oracle, creating a stored procedure requires the use of the PL/SQL programming language. The following is a simple example that demonstrates how to create a stored procedure.
CREATE OR REPLACE PROCEDURE procedure_name(param1 IN data_type1, param2 OUT data_type2) AS BEGIN /* SQL statements */ END procedure_name;
In the above example, procedure_name
is the name of the stored procedure, param1
is the input parameter, param2
is the output parameter, data_type1
and data_type2
are data types. Any number of SQL statements can be written between BEGIN
and END
of the stored procedure to perform data operations and business logic processing.
How to call a stored procedure?
There are two ways to call a stored procedure: using SQL Developer's GUI and using SQL statements.
Using SQL Developer's GUI
If you use the Oracle SQL Developer tool to execute SQL statements and manage the database, you can easily call stored procedures. Below is a simple example.
Step 1: Connect to the database
First, open Oracle SQL Developer. Select the database you want to connect to in the database tree on the left, right-click and select "Connect".
Step 2: Create a stored procedure
After connecting to the database, enter the following SQL code in the SQL Worksheet, and then run the code to create a stored procedure.
CREATE OR REPLACE PROCEDURE hello_world AS BEGIN DBMS_OUTPUT.PUT_LINE('Hello World!'); END hello_world;
Step 3: Execute the stored procedure
Enter the following code in the SQL Worksheet to call the stored procedure just created.
EXEC hello_world;
The results will be displayed in the "Output" tab at the bottom of the window.
Using SQL statements
You can also use SQL statements to call stored procedures. Below is a simple example.
Step 1: Create a stored procedure
Enter the following SQL code in SQL*Plus or SQL Worksheet to create a stored procedure.
CREATE OR REPLACE PROCEDURE hello_world AS BEGIN DBMS_OUTPUT.PUT_LINE('Hello World!'); END hello_world;
Step 2: Execute the stored procedure
Enter the following SQL code to execute the stored procedure just created.
EXEC hello_world;
The results will be displayed in the "Output" tab at the bottom of the window.
Summary
Stored procedures are a very important function in Oracle database. It can help developers process data operations and business logic more efficiently and reduce the number of database interactions, thus improving database performance. Through the above introduction, readers should be able to master the methods of creating and calling stored procedures in Oracle database, so as to better utilize these functions to improve their work efficiency.
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