search
HomeOperation and MaintenanceLinux Operation and MaintenanceExamples to explain how to use Oracle stored procedures to implement paging queries

In Oracle database, stored procedures can be used to implement many complex logics, among which paging queries are also one of the common requirements. This article will introduce how to use Oracle stored procedures to implement paging queries and provide an example.

1. Requirements for paging query

In actual applications, it is usually necessary to query and display a large amount of data. If all data is displayed at once, it will not only affect system performance, but also cause poor user experience. Therefore, we usually need to display the data in pages and display the data page by page.

In Oracle database, paging queries are usually implemented using the ROWNUM keyword. For example, to query the first 10 records in the database, you can use the following query statement:

SELECT *
FROM table_name
WHERE ROWNUM <p>This query statement can return the first 10 data in the table and implement simple paging query. But when you need to query the 11th to 20th data, you need to use a more complex query statement: </p><pre class="brush:php;toolbar:false">SELECT *
FROM (
  SELECT ROWNUM rn, t.*
  FROM (
    SELECT *
    FROM table_name
    ORDER BY field_name
  ) t
  WHERE ROWNUM = 11;

This query statement can return the 11th to 20th data in the table. However, this query statement is relatively complex and not very readable. If there are many places where paging queries are required, many such query statements need to be written, which is not convenient for maintenance and management.

In order to solve this problem, we can use Oracle stored procedures to implement the paging query function.

2. Use stored procedures to implement paging query

Use stored procedures to implement paging query function, mainly by passing parameters. We need to pass the following parameters:

  • Table name;
  • Column to be displayed;
  • Sort field;
  • Page;
  • The number of records displayed on each page.

Based on these parameters, the stored procedure can implement paging queries based on the ROWNUM keyword.

The following is an example of using a stored procedure to implement paging query:

CREATE OR REPLACE PROCEDURE get_page_data(
    p_table_name IN VARCHAR2,
    p_columns IN VARCHAR2,
    p_order_by IN VARCHAR2,
    p_page_num IN NUMBER,
    p_page_size IN NUMBER,
    p_result OUT SYS_REFCURSOR
)
IS
BEGIN
    OPEN p_result FOR
        SELECT *
        FROM (
            SELECT ROWNUM rn, t.*
            FROM (
                SELECT p_columns
                FROM p_table_name
                ORDER BY p_order_by
            ) t
            WHERE ROWNUM = (p_page_num - 1) * p_page_size + 1;
END;
/

In this stored procedure, the SYS_REFCURSOR type is used to return query results. Then, a paging query statement is generated based on the passed parameters, and finally the query results are put into the returned result set.

When calling this stored procedure, you can use the following query:

DECLARE
    v_result SYS_REFCURSOR;
BEGIN
    get_page_data('table_name', '*', 'field_name', 2, 10, v_result);
END;
/

This query will return the data on page 2 of the table, with 10 records displayed on each page.

In short, using stored procedures can easily implement the paging query function, making the code clearer, easier to understand, and more maintainable. The above example has provided an idea that can be modified and expanded according to actual needs.

The above is the detailed content of Examples to explain how to use Oracle stored procedures to implement paging queries. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Tutorial on finding keywords for common Linux commandsTutorial on finding keywords for common Linux commandsMar 05, 2025 am 11:45 AM

This tutorial demonstrates efficient keyword searching in Linux using the grep command family and related tools. It covers basic and advanced techniques, including regular expressions, recursive searches, and combining commands like awk, sed, and xa

Work content of Linux operation and maintenance engineers What does Linux operation and maintenance engineers do?Work content of Linux operation and maintenance engineers What does Linux operation and maintenance engineers do?Mar 05, 2025 am 11:37 AM

This article details the multifaceted role of a Linux system administrator, encompassing system maintenance, troubleshooting, security, and collaboration. It highlights essential technical and soft skills, salary expectations, and diverse career pr

How do I configure SELinux or AppArmor to enhance security in Linux?How do I configure SELinux or AppArmor to enhance security in Linux?Mar 12, 2025 pm 06:59 PM

This article compares SELinux and AppArmor, Linux kernel security modules providing mandatory access control. It details their configuration, highlighting the differences in approach (policy-based vs. profile-based) and potential performance impacts

How do I back up and restore a Linux system?How do I back up and restore a Linux system?Mar 12, 2025 pm 07:01 PM

This article details Linux system backup and restoration methods. It compares full system image backups with incremental backups, discusses optimal backup strategies (regularity, multiple locations, versioning, testing, security, rotation), and da

How do I use regular expressions (regex) in Linux for pattern matching?How do I use regular expressions (regex) in Linux for pattern matching?Mar 17, 2025 pm 05:25 PM

The article explains how to use regular expressions (regex) in Linux for pattern matching, file searching, and text manipulation, detailing syntax, commands, and tools like grep, sed, and awk.

How do I monitor system performance in Linux using tools like top, htop, and vmstat?How do I monitor system performance in Linux using tools like top, htop, and vmstat?Mar 17, 2025 pm 05:28 PM

The article discusses using top, htop, and vmstat for monitoring Linux system performance, detailing their unique features and customization options for effective system management.

How do I implement two-factor authentication (2FA) for SSH in Linux?How do I implement two-factor authentication (2FA) for SSH in Linux?Mar 17, 2025 pm 05:31 PM

The article provides a guide on setting up two-factor authentication (2FA) for SSH on Linux using Google Authenticator, detailing installation, configuration, and troubleshooting steps. It highlights the security benefits of 2FA, such as enhanced sec

Methods for uploading files for common Linux commandsMethods for uploading files for common Linux commandsMar 05, 2025 am 11:42 AM

This article compares Linux commands (scp, sftp, rsync, ftp) for uploading files. It emphasizes security (favoring SSH-based methods) and efficiency, highlighting rsync's delta transfer capabilities for large files. The choice depends on file size,

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

MinGW - Minimalist GNU for Windows

MinGW - Minimalist GNU for Windows

This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),