


MYSQL index types: PRIMARY, INDEX, UNIQUE, FULLTEXT, SPAIAL What are the differences? What occasions is each suitable for? , fulltextspaial_PHP tutorial
What are the differences between MYSQL index types: PRIMARY, INDEX, UNIQUE, FULLTEXT, SPAIAL? What occasions is each suitable for? , fulltextspaial
Mysql common indexes are: primary key index, unique index, ordinary index, full-text index, combined index
PRIMARY KEY (Primary key index) ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` ) UNIQUE (unique index) ALTER TABLE `table_name` ADD UNIQUE (`column`)
INDEX (normal index) ALTER TABLE `table_name` ADD INDEX index_name ( `column` ) FULLTEXT (full-text index) ALTER TABLE `table_name` ADD FULLTEXT ( `column` )
Combined index ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` )
The difference between various Mysql indexes:
Normal index (INDEX): the most basic index, without any restrictions
Unique index (UNIQUE): similar to "normal index", the difference is: index Column values must be unique, but null values are allowed.
Primary key index (PRIMARY): It is a special unique index that does not allow null values.
Full-text index (FULLTEXT): It can only be used for MyISAM tables. It is used to retrieve text information in an article. For larger data, it is very time-consuming and space-consuming to generate a full-text index.
Combined index: In order to further improve the efficiency of mysql, a composite index can be established, following the "leftmost prefix" principle.
For example , let’s say you are making a membership card system for a shopping mall.
This system has a membership table
with the following fields:
Member number INT
Member Name VARCHAR(10)
Member ID number VARCHAR(18)
Member phone number VARCHAR(10)
Member address VARCHAR( 50)
Member remark information TEXT
Then this member number, as the primary key, uses PRIMARY
member name. If you want to build an index, then it is an ordinary INDEX
member ID card If you want to build an index for the number, you can choose UNIQUE (unique, no duplicates allowed)
Member’s remarks information. If you need to build an index, you can choose FULLTEXT for full-text search.
However, FULLTEXT works best when used to search for a long article.
is used for relatively short text. If it is only one or two lines, ordinary INDEX can also be used.
Create index: CREATE UNIQUE INDEX indexName ON tableName(tableColumns(length))
Syntax to delete index: DROP INDEX index_name ON tableName

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

You can open phpMyAdmin through the following steps: 1. Log in to the website control panel; 2. Find and click the phpMyAdmin icon; 3. Enter MySQL credentials; 4. Click "Login".

MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.

Redis uses a single threaded architecture to provide high performance, simplicity, and consistency. It utilizes I/O multiplexing, event loops, non-blocking I/O, and shared memory to improve concurrency, but with limitations of concurrency limitations, single point of failure, and unsuitable for write-intensive workloads.

MySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.

MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

Effective monitoring of Redis databases is critical to maintaining optimal performance, identifying potential bottlenecks, and ensuring overall system reliability. Redis Exporter Service is a powerful utility designed to monitor Redis databases using Prometheus. This tutorial will guide you through the complete setup and configuration of Redis Exporter Service, ensuring you seamlessly build monitoring solutions. By studying this tutorial, you will achieve fully operational monitoring settings
