How to query empty fields in oracle-Oracle-php.cn

Home

Database

Oracle

How to query empty fields in oracle

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Feb 28, 2022 am 11:44 AM

oracle

In Oracle, you can use the select query statement with the "is" and "NULL" keywords to query empty fields. The NULL keyword is used to represent empty fields. The syntax is "select * from table name where field name. is NULL".

How to query empty fields in oracle

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

How to query empty fields in oracle

Oracle queries empty data

where 字段名 is NULL

How to query empty fields in oracle

Empty fields are special values. This statement checks If

select gysname,gysdl,gysxl from formtable_main_674 where    gysdl=1 and gysxl=&#39;&#39;

How to query empty fields in oracle

happens, we use is to query

select gysname,gysdl,gysxl from formtable_main_674 where    gysdl=1 and gysxl is null

How to query empty fields in oracle

Recommended tutorial: "Oracle Video Tutorial》

The above is the detailed content of How to query empty fields in oracle. For more information, please follow other related articles on the PHP Chinese website!

Statement

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

MySQL vs. Oracle: Understanding Licensing and CostMay 03, 2025 am 12:19 AM

MySQL uses GPL and commercial licenses for small and open source projects; Oracle uses commercial licenses for enterprises that require high performance. MySQL's GPL license is free, and commercial licenses require payment; Oracle license fees are calculated based on processors or users, and the cost is relatively high.

Oracle: From Databases to Cloud ServicesMay 02, 2025 am 12:05 AM

Oracle's evolution from database to cloud services demonstrates its strong technical strength and market insight. 1. Oracle originated in the 1970s and is famous for its relational database management system, and has launched innovative functions such as PL/SQL. 2. The core of Oracle database is relational model and SQL optimization, which supports multi-tenant architecture. 3. Oracle cloud services provide IaaS, PaaS and SaaS through OCI, and AutonomousDatabase performs well. 4. When using Oracle, you need to pay attention to the complex licensing model, performance optimization and data security issues in cloud migration.

Oracle and MySQL: Exploring Data Management ApproachesMay 01, 2025 am 12:13 AM

Oracle is suitable for enterprise-level applications that require high performance and complex queries, and MySQL is suitable for web applications that are rapidly developed and deployed. 1. Oracle supports complex transaction processing and high availability, suitable for financial and large ERP systems. 2.MySQL emphasizes ease of use and open source support, and is widely used in small and medium-sized enterprises and Internet projects.

MySQL vs. Oracle: A Look at the User ExperienceApr 30, 2025 am 12:12 AM

The differences in user experience between MySQL and Oracle are mainly reflected in: 1. MySQL is simple and easy to use, suitable for quick access and high flexibility scenarios; 2. Oracle has powerful functions, suitable for scenarios that require enterprise-level support. MySQL's open source and free features attract startups and individual developers, while Oracle's complex features and tools meet the needs of large enterprises.

MySQL and Oracle: Exploring Performance and ScalabilityApr 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.

What Oracle Software Does: Key Functions and FeaturesApr 28, 2025 am 12:08 AM

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's Impact: Data Management and BeyondApr 27, 2025 am 12:11 AM

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: Exploring the Company's Mission and ValueApr 26, 2025 am 12:06 AM

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.

See all articles