MYSQL必知必会读书笔记第五章之排序检索数据

Home

Database

Mysql Tutorial

MYSQL必知必会读书笔记第五章之排序检索数据_MySQL

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

May 27, 2016 pm 01:44 PM

MySQL是一种开放源代码的关系型数据库管理系统（RDBMS），MySQL数据库系统使用最常用的数据库管理语言--结构化查询语言（SQL）进行数据库管理。

其实，检索出的数据并不是以纯随机顺序显示的。如果不排序，数据一般将以它底层表现中出现的顺序显示。这可以是数据最初添加到表中的顺序。但是，如果数据后来进行过更新或删除，则此顺序将会受到MySQL重用回收存储空间的影响。因此，如果不明确控制的话，不能依赖该排序顺序。

在多个列上将序排列：如果想在多个列上进行将序排列，必须每个列指定DESC关键字

ORDER BY子句的位置：在给出ORDER BY子时，应该保证它位于FROM子句之后。如果使用LIMIT 关键字则LIMIT必须出现在ORDER BY之后。

以上内容是小编给大家分享的MYSQL必知必会读书笔记第五章之排序检索数据的相关内容，希望对大家有所帮助，同时也非常感谢大家对网站的支持！

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

How do you alter a table in MySQL using the ALTER TABLE statement?Mar 19, 2025 pm 03:51 PM

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

How do I configure SSL/TLS encryption for MySQL connections?Mar 18, 2025 pm 12:01 PM

Article discusses configuring SSL/TLS encryption for MySQL, including certificate generation and verification. Main issue is using self-signed certificates' security implications.[Character count: 159]

How do you handle large datasets in MySQL?Mar 21, 2025 pm 12:15 PM

Article discusses strategies for handling large datasets in MySQL, including partitioning, sharding, indexing, and query optimization.

What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)?Mar 21, 2025 pm 06:28 PM

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]

How do you drop a table in MySQL using the DROP TABLE statement?Mar 19, 2025 pm 03:52 PM

The article discusses dropping tables in MySQL using the DROP TABLE statement, emphasizing precautions and risks. It highlights that the action is irreversible without backups, detailing recovery methods and potential production environment hazards.

How do you represent relationships using foreign keys?Mar 19, 2025 pm 03:48 PM

Article discusses using foreign keys to represent relationships in databases, focusing on best practices, data integrity, and common pitfalls to avoid.

How do you create indexes on JSON columns?Mar 21, 2025 pm 12:13 PM

The article discusses creating indexes on JSON columns in various databases like PostgreSQL, MySQL, and MongoDB to enhance query performance. It explains the syntax and benefits of indexing specific JSON paths, and lists supported database systems.

How do I secure MySQL against common vulnerabilities (SQL injection, brute-force attacks)?Mar 18, 2025 pm 12:00 PM

Article discusses securing MySQL against SQL injection and brute-force attacks using prepared statements, input validation, and strong password policies.(159 characters)

See all articles