In Oracle, the case statement is used to compare the expression result with several provided foreseeable results. If the comparison is successful, the corresponding statement sequence is executed. The syntax is "CASE expression WHEN expression result 1 THEN executable [WHEN expression result 2 THEN executable]...".
The operating environment of this tutorial: Windows 10 system, Oracle version 12c, Dell G3 computer.
How to use case in oracle
This statement can compare the expression result with several foreseeable results provided. If the comparison is successful, the corresponding statement sequence will be executed. The syntax is " CASE expression WHEN expression result 1 THEN execution item [WHEN expression result 2 THEN execution item]...".
There are case statements in oracle
case statements can be divided into two types:
One is a simple case statement, which gives a Expression, and compares the expression result with several provided predictable results. If the comparison is successful, the corresponding statement sequence is executed.
The other is the search-style case statement. It will provide multiple Boolean expressions, then select the first expression that is true and execute the corresponding script.
1. Simple case statement
Syntax:
case exp when comexp then returnvalue … when comexp then returnvalue else returnvalue end
The period from case to end is equivalent to a specific value, which can be used for calculations and aliases , nested cases, etc.
Just treat case to end as an expression of the operation result.
Example:
2. Search case statement
Grammar:
case when boolean then return value … when boolean then return value else retur nvalue end
Example :
The difference between simple case and search case:
Simple case can only be when The following expression completely matches the expression after the case, which is equivalent to =, so it cannot match null.
searched case can be used as a comparison condition, then you can use like, !=, between...and,
Recommended tutorial: "Oracle Video Tutorial"
The above is the detailed content of How to use case in oracle. For more information, please follow other related articles on the PHP Chinese website!

Key features of Oracle software include multi-tenant architecture, advanced analytics and data mining, real-time application clustering (RAC), and automated management and monitoring. 1) A multi-tenant architecture allows for the management of multiple independent databases in one database instance, simplifying management and reducing costs. 2) Advanced analytics and data mining tools such as Oracle Advanced Analytics and OracleDataMining help extract insights from data. 3) Real-time application cluster (RAC) provides high availability and scalability, improving system fault tolerance and performance. 4) Automated management and monitoring tools such as Oracle EnterpriseManager (OEM) to automate daily maintenance tasks and monitor numbers in real time

Oracle has a profound impact in the fields of data management and enterprise applications. Its database is known for its reliability, scalability and security, and is widely used in industries such as finance, medical care and government. Oracle's influence has also expanded to middleware and cloud computing fields such as WebLogicServer and OracleCloudInfrastructure (OCI), providing innovative solutions. Despite the competition in the open source database and cloud computing market, Oracle maintains its leading position through continuous innovation.

Oracle's mission is to "help people see the value of data", and its core values include: 1) Customer first, 2) Integrity, 3) Innovation, and 4) Teamwork. These values guide Oracle's strategic decision-making and business innovation in the market.

Oracle Database is a relational database management system that supports SQL and object relational models to provide data security and high availability. 1. The core functions of Oracle database include data storage, retrieval, security and backup and recovery. 2. Its working principle involves multi-layer storage structure, MVCC mechanism and optimizer. 3. Basic usages include creating tables, inserting and querying data; advanced usages involve stored procedures and triggers. 4. Performance optimization strategies include the use of indexes, optimized SQL statements and memory management.

In addition to database management, Oracle software is also used in JavaEE applications, data grids and high-performance computing. 1. OracleWebLogicServer is used to deploy and manage JavaEE applications. 2. OracleCoherence provides high-performance data storage and caching services. 3. OracleExadata is used for high performance computing. These tools allow Oracle to play a more diversified role in the enterprise IT architecture.

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.

Oracle software applications in the real world include e-commerce platforms and manufacturing. 1) On e-commerce platforms, OracleDatabase is used to store and query user information. 2) In manufacturing, OracleE-BusinessSuite is used to optimize inventory and production planning.

The reason why Oracle software shines in multiple fields is its powerful application and customized solutions. 1) Oracle provides comprehensive solutions from database management to ERP, CRM, SCM, 2) its solutions can be customized according to industry characteristics such as finance, medical care, manufacturing, etc. 3) Successful cases include Citibank, Mayo Clinic and Toyota, 4) The advantages lie in comprehensiveness, customization and scalability, but challenges include complexity, cost and integration issues.


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

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

Hot Article

Hot Tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

SublimeText3 Chinese version
Chinese version, very easy to use

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

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.
