Oracle中两个记录约束的系统表
例如,我现在要删除TBL_USER表中的某条记录,此时会报错误:ORA-02292 integrity constraint (ESAWEB.FK_TBL_USER_REFERENCE_TBL
当要查询某一个约束在哪个表中时,会用到下面两个系统表。
user_constraints约束表,记录该用户的所有约束。如非空,索引等等。
user_cons_columns约束字段表,记录每个约束涉及到的所有字段。
例如,,我现在要删除TBL_USER表中的某条记录,此时会报错误:ORA-02292 integrity constraint (ESAWEB.FK_TBL_USER_REFERENCE_TBL_USER) violated - child record found.错误,说明TBL_USER表的某一列有外键约束,此时需要找到这个外键约束的表中记录并删除。
select * from user_constraints t where t.CONSTRAINT_NAME = ' FK_TBL_USER_REFERENCE_TBL_USER ' ;
找到TABLE_NAME字段中的值,这里面的值就是存在FK_TBL_USER_REFERENCE_TBL_USER约束的表,在此表中找到相应记录并删除即可。

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

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



Go language is an efficient, concise and easy-to-learn programming language. It is favored by developers because of its advantages in concurrent programming and network programming. In actual development, database operations are an indispensable part. This article will introduce how to use Go language to implement database addition, deletion, modification and query operations. In Go language, we usually use third-party libraries to operate databases, such as commonly used sql packages, gorm, etc. Here we take the sql package as an example to introduce how to implement the addition, deletion, modification and query operations of the database. Assume we are using a MySQL database.

Hibernate polymorphic mapping can map inherited classes to the database and provides the following mapping types: joined-subclass: Create a separate table for the subclass, including all columns of the parent class. table-per-class: Create a separate table for subclasses, containing only subclass-specific columns. union-subclass: similar to joined-subclass, but the parent class table unions all subclass columns.

Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps

HTML cannot read the database directly, but it can be achieved through JavaScript and AJAX. The steps include establishing a database connection, sending a query, processing the response, and updating the page. This article provides a practical example of using JavaScript, AJAX and PHP to read data from a MySQL database, showing how to dynamically display query results in an HTML page. This example uses XMLHttpRequest to establish a database connection, send a query and process the response, thereby filling data into page elements and realizing the function of HTML reading the database.

How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())

To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.

PHP is a back-end programming language widely used in website development. It has powerful database operation functions and is often used to interact with databases such as MySQL. However, due to the complexity of Chinese character encoding, problems often arise when dealing with Chinese garbled characters in the database. This article will introduce the skills and practices of PHP in handling Chinese garbled characters in databases, including common causes of garbled characters, solutions and specific code examples. Common reasons for garbled characters are incorrect database character set settings: the correct character set needs to be selected when creating the database, such as utf8 or u

Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.
