Method: 1. Use the DROP SEQUENCE statement to delete the sequence, and then use the Create sequence statement to create a new one; 2. Use Increment By to modify the initial value of the sequence, and the syntax is "ALTER SEQUENCE...INCREMENT BY value".
The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.
How to modify sequence in oracle
Oracle sequence (Sequence) is mainly used to generate serial numbers and is often used in applications, especially as ID values, which are often used as table primary keys. .
However, sometimes when it is necessary to modify the sequence initial value (START WITH), some colleagues use this statement to modify: alter sequence sequencename start with xxxxxxxx. However, in Oracle DB, there is no such syntax for modifying sequences. Here are several modification methods:
1. Delete the sequence first, and then create it again.
This method is more violent and more convenient. If the sequence is in use, it will affect the normal use of the application.
If no conditional statement is added, the default sequence format created is as follows:
Semantics:
INCREMENT BY: Specify the sequence growth step long. Can be positive (ascending order) or negative integer (descending order), but cannot be 0. Maximum accuracy 28.
START WITH: Specify the starting number of the sequence. Defaults to the sequence minimum.
MAXVALUE: Specifies the maximum value of the sequence. Maximum 28 bits. Must be greater than or equal to the starting value and greater than or equal to the minimum value of the sequence.
NOMAXVALUE: No maximum value (actually 10^27 or -1). default
MINVALUE: Specifies the sequence minimum value.
NOMINVALUE: No minimum value (actually 1 or -10^26). Default
CYCLE: Specifies that the sequence will continue to be generated from scratch after reaching the maximum or minimum value.
NOCYCLE: No cycle generation. Default.
CACHE: Specify the number of sequence values pre-allocated in the database memory for quick retrieval. The minimum cache value is 2.
To delete a sequence, you must have the drop any sequence permission
Syntax:
DROP SEQUENCE oe.customers_seq;
2. Modify the initial value through Increment By.
For example: If the sequence name is SEQ_TEST, the initial value is 13, and now you want to set the initial value to 1013, the Increment By value is: 1000(1013-13)1) Execution:ALTER SEQUENCE SEQ_TEST INCREMENT BY 1000;2) Execution:
SELECT SEQ_TEST.NEXTVAL FROM DUAL;3) Execution:
ALTER SEQUENCE SEQ_TEST INCREMENT BY 1;Recommended tutorial: "
Oracle Video Tutorial"
The above is the detailed content of How to modify sequence in oracle. For more information, please follow other related articles on the PHP Chinese website!
Oracle's Products: A Deep DiveApr 19, 2025 am 12:14 AMOracle's product ecosystem includes databases, middleware and cloud services. 1. OracleDatabase is its core product, supporting efficient data storage and management. 2. Middleware such as OracleWebLogicServer connects to different systems. 3. OracleCloud provides a complete set of cloud computing solutions.
MySQL and Oracle: Key Differences in Features and FunctionalityApr 18, 2025 am 12:15 AMMySQL and Oracle each have advantages in performance, scalability, and security. 1) Performance: MySQL is suitable for read operations and high concurrency, and Oracle is good at complex queries and big data processing. 2) Scalability: MySQL extends through master-slave replication and sharding, and Oracle uses RAC to provide high availability and load balancing. 3) Security: MySQL provides fine-grained permission control, while Oracle has more comprehensive security functions and automation tools.
Oracle: The Powerhouse of Database ManagementApr 17, 2025 am 12:14 AMOracle is called the "Powerhouse" of database management because of its high performance, reliability and security. 1. Oracle is a relational database management system that supports multiple operating systems. 2. It provides a powerful data management platform with scalability, security and high availability. 3. Oracle's working principles include data storage, query processing and transaction management, and supports performance optimization technologies such as indexing, partitioning and caching. 4. Examples of usage include creating tables, inserting data, and writing stored procedures. 5. Performance optimization strategies include index optimization, partition table, cache management and query optimization.
What Does Oracle Offer? Products and Services ExplainedApr 16, 2025 am 12:03 AMOracleoffersacomprehensivesuiteofproductsandservicesincludingdatabasemanagement,cloudcomputing,enterprisesoftware,andhardwaresolutions.1)OracleDatabasesupportsvariousdatamodelswithefficientmanagementfeatures.2)OracleCloudInfrastructure(OCI)providesro
Oracle Software: From Databases to the CloudApr 15, 2025 am 12:09 AMThe development history of Oracle software from database to cloud computing includes: 1. Originated in 1977, it initially focused on relational database management system (RDBMS), and quickly became the first choice for enterprise-level applications; 2. Expand to middleware, development tools and ERP systems to form a complete set of enterprise solutions; 3. Oracle database supports SQL, providing high performance and scalability, suitable for small to large enterprise systems; 4. The rise of cloud computing services further expands Oracle's product line to meet all aspects of enterprise IT needs.
MySQL vs. Oracle: The Pros and ConsApr 14, 2025 am 12:01 AMMySQL and Oracle selection should be based on cost, performance, complexity and functional requirements: 1. MySQL is suitable for projects with limited budgets, is simple to install, and is suitable for small to medium-sized applications. 2. Oracle is suitable for large enterprises and performs excellently in handling large-scale data and high concurrent requests, but is costly and complex in configuration.
Oracle's Purpose: Business Solutions and Data ManagementApr 13, 2025 am 12:02 AMOracle helps businesses achieve digital transformation and data management through its products and services. 1) Oracle provides a comprehensive product portfolio, including database management systems, ERP and CRM systems, helping enterprises automate and optimize business processes. 2) Oracle's ERP systems such as E-BusinessSuite and FusionApplications realize end-to-end business process automation, improve efficiency and reduce costs, but have high implementation and maintenance costs. 3) OracleDatabase provides high concurrency and high availability data processing, but has high licensing costs. 4) Performance optimization and best practices include the rational use of indexing and partitioning technology, regular database maintenance and compliance with coding specifications.
How to delete oracle library failureApr 12, 2025 am 06:21 AMSteps to delete the failed database after Oracle failed to build a library: Use sys username to connect to the target instance. Use DROP DATABASE to delete the database. Query v$database to confirm that the database has been deleted.
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
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
WebStorm Mac version
Useful JavaScript development tools
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
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.
