Home Database Mysql Tutorial mysql与oracle的区别_MySQL

mysql与oracle的区别_MySQL

Jun 01, 2016 pm 01:31 PM
mysql oracle database

bitsCN.com

mysql与oracle的区别

 

1.mysql与oracle数据库实现自增列的区别:

mysql可以实现自增列,只要在建表时设置auto_increment即可,而oracle在建表时不能设置自增列功能,

必须通过sequence序列来实现自增列功能,建立sequence序列的语句如下(假设序列名为ts_sequence):

CREATE SEQUENCE ts_sequenceINCREMENT BY 1 -- 每次加几个START WITH 1 -- 从1开始计数NOMAXVALUE -- 不设置最大值NOCYCLE -- 一直累加,不循环CACHE 10;
Copy after login

定义了sequence以后就可以在insert语句中使用ts_sequence.nextval和ts_sequence.currval,

ts_sequence.currval返回当前sequence的值,但必须在第一次初始化ts_sequence.nextval后才能使用

ts_sequence.currval。

2.mysql与oracle数据库索引的区别:

在整个数据库内,mysql的索引可以同名,也就是说mysql的索引是表级别的;但是Oracle索引不可以同名,也就是说Oracle的索引是数据库级别的;

mysql的索引是从0开始,oracle的索引是从1开始。

创建索引两者相同:create index indexName on tableName (columnName);删除索引mysql:alter table tableName drop index indexName oracle:drop index indexName查询表的索引mysql:show index from tableName Oracle:select index_name, table_name,column_name from user_ind_columns where table_name=' tableName '
Copy after login

 


bitsCN.com
Statement of this Website
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

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

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Roblox: Bubble Gum Simulator Infinity - How To Get And Use Royal Keys
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Nordhold: Fusion System, Explained
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Mandragora: Whispers Of The Witch Tree - How To Unlock The Grappling Hook
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1677
14
PHP Tutorial
1280
29
C# Tutorial
1257
24
Explain the purpose of foreign keys in MySQL. Explain the purpose of foreign keys in MySQL. Apr 25, 2025 am 12:17 AM

In MySQL, the function of foreign keys is to establish the relationship between tables and ensure the consistency and integrity of the data. Foreign keys maintain the effectiveness of data through reference integrity checks and cascading operations. Pay attention to performance optimization and avoid common errors when using them.

Compare and contrast MySQL and MariaDB. Compare and contrast MySQL and MariaDB. Apr 26, 2025 am 12:08 AM

The main difference between MySQL and MariaDB is performance, functionality and license: 1. MySQL is developed by Oracle, and MariaDB is its fork. 2. MariaDB may perform better in high load environments. 3.MariaDB provides more storage engines and functions. 4.MySQL adopts a dual license, and MariaDB is completely open source. The existing infrastructure, performance requirements, functional requirements and license costs should be taken into account when choosing.

SQL vs. MySQL: Clarifying the Relationship Between the Two SQL vs. MySQL: Clarifying the Relationship Between the Two Apr 24, 2025 am 12:02 AM

SQL is a standard language for managing relational databases, while MySQL is a database management system that uses SQL. SQL defines ways to interact with a database, including CRUD operations, while MySQL implements the SQL standard and provides additional features such as stored procedures and triggers.

MySQL: The Database, phpMyAdmin: The Management Interface MySQL: The Database, phpMyAdmin: The Management Interface Apr 29, 2025 am 12:44 AM

MySQL and phpMyAdmin can be effectively managed through the following steps: 1. Create and delete database: Just click in phpMyAdmin to complete. 2. Manage tables: You can create tables, modify structures, and add indexes. 3. Data operation: Supports inserting, updating, deleting data and executing SQL queries. 4. Import and export data: Supports SQL, CSV, XML and other formats. 5. Optimization and monitoring: Use the OPTIMIZETABLE command to optimize tables and use query analyzers and monitoring tools to solve performance problems.

Redis: Understanding Its Architecture and Purpose Redis: Understanding Its Architecture and Purpose Apr 26, 2025 am 12:11 AM

Redis is a memory data structure storage system, mainly used as a database, cache and message broker. Its core features include single-threaded model, I/O multiplexing, persistence mechanism, replication and clustering functions. Redis is commonly used in practical applications for caching, session storage, and message queues. It can significantly improve its performance by selecting the right data structure, using pipelines and transactions, and monitoring and tuning.

Detailed explanation of the installation steps of MySQL on macOS system Detailed explanation of the installation steps of MySQL on macOS system Apr 29, 2025 pm 03:36 PM

Installing MySQL on macOS can be achieved through the following steps: 1. Install Homebrew, using the command /bin/bash-c"$(curl-fsSLhttps://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)". 2. Update Homebrew and use brewupdate. 3. Install MySQL and use brewinstallmysql. 4. Start MySQL service and use brewservicesstartmysql. After installation, you can use mysql-u

Steps to add and delete fields to MySQL tables Steps to add and delete fields to MySQL tables Apr 29, 2025 pm 04:15 PM

In MySQL, add fields using ALTERTABLEtable_nameADDCOLUMNnew_columnVARCHAR(255)AFTERexisting_column, delete fields using ALTERTABLEtable_nameDROPCOLUMNcolumn_to_drop. When adding fields, you need to specify a location to optimize query performance and data structure; before deleting fields, you need to confirm that the operation is irreversible; modifying table structure using online DDL, backup data, test environment, and low-load time periods is performance optimization and best practice.

MySQL and Oracle: Exploring Performance and Scalability MySQL and Oracle: Exploring Performance and Scalability Apr 29, 2025 am 12:12 AM

The difference between MySQL and Oracle in performance and scalability is: 1. MySQL performs better on small to medium-sized data sets, suitable for fast scaling and efficient reading and writing; 2. Oracle has more advantages in handling large data sets and complex queries, suitable for high availability and complex business logic. MySQL extends through master-slave replication and sharding technologies, while Oracle achieves high availability and scalability through RAC.

See all articles