Let's talk in depth about stored procedures and temporary tables in Oracle

Oracle database is currently one of the most popular and widely used relational databases. It provides many powerful functions and features to facilitate developers, DBAs and business personnel to perform data management, query analysis and other tasks. Among them, stored procedures and temporary tables are very important functions in the Oracle database. This article will take Oracle stored procedures and temporary tables as the theme to deeply explore their implementation principles and application scenarios.

1. Stored procedure

A stored procedure is a reusable SQL code created in advance. It can be called to perform some complex business logic without having to write it repeatedly. The same SQL statement. Stored procedures are usually used to perform complex data processing, transaction processing, automated processing and other tasks.

In Oracle database, stored procedures can be written in PL/SQL, which is a procedural programming language based on Oracle SQL language. It is very powerful and easy to use. Through stored procedures, we can complete a large number of complex data processing and computing tasks, improving system operating efficiency and data processing capabilities.

The following is a simple Oracle stored procedure implementation example:

CREATE OR REPLACE PROCEDURE proc_test AS
BEGIN
  FOR i IN 1..10 LOOP
    INSERT INTO mytable (id, name) VALUES (i, 'test');
  END LOOP;
END;

In the above example, we created a stored procedure named proc_test, in which we used a loop statement to convert the data Insert into a table named mytable.

2. Temporary table

The temporary table is a temporary table that only exists in the current database connection. After the connection is closed, the temporary table will be automatically deleted. . Temporary tables are often used to store intermediate result data, or to perform data processing and calculation tasks in temporary scenarios.

Oracle database provides two types of temporary tables, GLOBAL TEMPORARY TABLE and LOCAL TEMPORARY TABLE. Among them, GLOBAL TEMPORARY TABLE is a temporary table shared among all user sessions, while LOCAL TEMPORARY TABLE is a temporary table created in the current user session.

The following is an example of an Oracle temporary table implementation:

CREATE GLOBAL TEMPORARY TABLE temp_table
(
  id   NUMBER,
  name VARCHAR2(20)
) ON COMMIT DELETE ROWS;

In the above example, we created a global temporary table named temp_table, which only exists in the current database connection, and Automatically delete all rows in the table when the transaction commits. This table contains two fields: id and name, which are integer and string respectively.

3. Application scenarios of stored procedures and temporary tables

Stored procedures and temporary tables are widely used in Oracle databases and are often used in the following scenarios:

3.1 Data processing and computing tasks

Stored procedures and temporary tables are very suitable for complex data processing and computing tasks. Through stored procedures, we can package complex data processing logic into a reusable code library to facilitate program calling and management. Through temporary tables, we can store intermediate result data and perform data query, summary, sorting, filtering and other calculation operations when needed.

3.2 Transaction processing and error handling

Stored procedures can also be used for transaction processing and error handling. When performing data modification operations, we usually need to use transactions to ensure data consistency and integrity, and stored procedures can easily implement batch submission and rollback of transactions. In addition, when handling errors, stored procedures can also capture and handle error information through the exception handling mechanism.

3.3 Data Import and Export

Temporary tables are very suitable for data import and export tasks. By creating a temporary table, we can store the imported data in the table, then perform data cleaning, reorganization, summarization and other operations, and finally export the data to other tables or files. In addition, temporary tables can also facilitate data backup and recovery to ensure data reliability and integrity.

Summary:

Stored procedures and temporary tables are very powerful and practical functions in Oracle database. They can improve the efficiency of data processing and management, and also facilitate developers to reuse code and maintain. Whether you are performing tasks such as data processing, transaction processing, error handling, or data import and export, you can consider using stored procedures and temporary tables to improve work efficiency and data processing capabilities.

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