How to add sequence in oracle
In Oracle, you can use the CREATE SEQUENCE statement to add a sequence. The syntax is "CREATE SEQUENCE [user.]sequence_name [interval between sequence numbers] [first sequence number] [maximum value that can be generated] [minimum value of sequence]".
The operating environment of this tutorial: Windows 10 system, Oracle version 12c, Dell G3 computer.
How to add a sequence in oracle
CREATE SEQUENCE [user.]sequence_name 序列号之间的间隔 第一个序列号 可生成的最大值 序列的最小值
A sequence is a database object that can be used to generate unique integers. Sequences are generally used to automatically generate primary code values. The values of a sequence are automatically generated by a special Oracle program, so the sequence avoids the performance bottleneck caused by implementing the sequence at the application layer.
Oracle sequence allows multiple sequence numbers to be generated at the same time, and each sequence number is unique. When a sequence number is generated, the sequence is incremented independently of the transaction's commit or rollback. Allows designing default sequences without specifying any clauses. This sequence is an ascending sequence, starting from 1, incrementing by 1, and has no upper limit.
1) Create sequence command
CREATE SEQUENCE [user.]sequence_name
[increment by n]
[start with n]
[maxvalue n | nomaxvalue]
[minvalue n | nominvalue];INCREMENT BY: Specify the interval between sequence numbers. The value can be a positive or negative integer, but cannot be 0 . The sequence is in ascending order. When this clause is omitted, the default value is 1.
START WITH: Specify the first serial number generated. In ascending order, the sequence can start with a value greater than the minimum value, and the default value is the minimum value of the sequence. For descending order, the sequence can start with a value smaller than the maximum value, and the default value is the maximum value of the sequence.
MAXVALUE: Specifies the maximum value that can be generated by the sequence.
NOMAXVALUE: Specify the maximum value as 1027 for ascending order and -1 for descending order.
MINVALUE: Specifies the minimum value of the sequence.
NOMINVALUE: Specify the minimum value as 1 for ascending order. Specify a minimum value of -1026 for descending order.
2) Change sequence command
ALTERSEQUENCE [user.]sequence_name
[INCREMENT BY n]
[MAXVALUE n| NOMAXVALUE ]
[MINVALUE n | NOMINVALUE]；To modify the sequence:
1) Modify the increment of future sequence values.
2) Set or cancel the minimum or maximum value.
3) Change the number of buffer sequences.
4) Specify whether the sequence number is in order.
5) Delete sequence command
Extended knowledge:
1. Add incremental sequence numbers to the same group
Syntax format:
row_number() over(partition by 分组列 order by 排序列 desc)
2. Add the same serial number to the same group
select id, dzid, dense_rank() over(order by dzid) 序号结果 from z_test;
Recommended tutorial: "Oracle Video Tutorial"
The above is the detailed content of How to add sequence in oracle. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
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
1795
16
1740
56
1592
29
1474
72
267
587
How to uninstall MySQL and clean residual files
Apr 29, 2025 pm 04:03 PM
To safely and thoroughly uninstall MySQL and clean all residual files, follow the following steps: 1. Stop MySQL service; 2. Uninstall MySQL packages; 3. Clean configuration files and data directories; 4. Verify that the uninstallation is thorough.
Oracle's Role in the Business World
Apr 23, 2025 am 12:01 AM
Oracle is not only a database company, but also a leader in cloud computing and ERP systems. 1. Oracle provides comprehensive solutions from database to cloud services and ERP systems. 2. OracleCloud challenges AWS and Azure, providing IaaS, PaaS and SaaS services. 3. Oracle's ERP systems such as E-BusinessSuite and FusionApplications help enterprises optimize operations.
MongoDB vs. Oracle: Understanding Key Differences
Apr 16, 2025 am 12:01 AM
MongoDB is suitable for handling large-scale unstructured data, and Oracle is suitable for enterprise-level applications that require transaction consistency. 1.MongoDB provides flexibility and high performance, suitable for processing user behavior data. 2. Oracle is known for its stability and powerful functions and is suitable for financial systems. 3.MongoDB uses document models, and Oracle uses relational models. 4.MongoDB is suitable for social media applications, while Oracle is suitable for enterprise-level applications.
MongoDB vs. Oracle: Choosing the Right Database for Your Needs
Apr 22, 2025 am 12:10 AM
MongoDB is suitable for unstructured data and high scalability requirements, while Oracle is suitable for scenarios that require strict data consistency. 1.MongoDB flexibly stores data in different structures, suitable for social media and the Internet of Things. 2. Oracle structured data model ensures data integrity and is suitable for financial transactions. 3.MongoDB scales horizontally through shards, and Oracle scales vertically through RAC. 4.MongoDB has low maintenance costs, while Oracle has high maintenance costs but is fully supported.
Centos options after stopping maintenance
Apr 14, 2025 pm 08:51 PM
CentOS has been discontinued, alternatives include: 1. Rocky Linux (best compatibility); 2. AlmaLinux (compatible with CentOS); 3. Ubuntu Server (configuration required); 4. Red Hat Enterprise Linux (commercial version, paid license); 5. Oracle Linux (compatible with CentOS and RHEL). When migrating, considerations are: compatibility, availability, support, cost, and community support.
Can vscode run kotlin
Apr 15, 2025 pm 06:57 PM
Running Kotlin in VS Code requires the following environment configuration: Java Development Kit (JDK) and Kotlin compiler Kotlin-related plugins (such as Kotlin Language and Kotlin Extension for VS Code) create Kotlin files and run code for testing to ensure successful environment configuration
What software is better for yi framework? Recommended software for yi framework
Apr 18, 2025 pm 11:03 PM
Abstract of the first paragraph of the article: When choosing software to develop Yi framework applications, multiple factors need to be considered. While native mobile application development tools such as XCode and Android Studio can provide strong control and flexibility, cross-platform frameworks such as React Native and Flutter are becoming increasingly popular with the benefits of being able to deploy to multiple platforms at once. For developers new to mobile development, low-code or no-code platforms such as AppSheet and Glide can quickly and easily build applications. Additionally, cloud service providers such as AWS Amplify and Firebase provide comprehensive tools
MySQL vs. Oracle: Licensing, Features, and Benefits
May 08, 2025 am 12:05 AM
The main difference between MySQL and Oracle is licenses, features, and advantages. 1. License: MySQL provides a GPL license for free use, and Oracle adopts a proprietary license, which is expensive. 2. Function: MySQL has simple functions and is suitable for web applications and small and medium-sized enterprises. Oracle has powerful functions and is suitable for large-scale data and complex businesses. 3. Advantages: MySQL is open source free, suitable for startups, and Oracle is reliable in performance, suitable for large enterprises.
