Course Introduction：Whether the SQL delete row triggers the trigger depends on the definition of the trigger. The trigger must specify explicitly what operation it responds to and under what conditions it triggers. If the trigger responds to a DELETE event and the condition is satisfied, it will be triggered. Examples include recording changes to deleted rows or triggering only deleting a specific row. Overuse of triggers or incorrectly designed can lead to performance problems and therefore require careful design and testing.

2025-04-09 comment 0  1000

Course Introduction：A SQL trigger is a database object that automatically performs specific actions when a specific event is executed on a specified table. To set up SQL triggers, you can use the CREATE TRIGGER statement, which includes the trigger name, table name, event type, and trigger code. The trigger code is defined using the AS keyword and contains SQL or PL/SQL statements or blocks. By specifying trigger conditions, you can use the WHERE clause to limit the execution scope of a trigger. Trigger operations can be performed in the trigger code using the INSERT INTO, UPDATE, or DELETE statement. NEW and OLD keywords can be used to reference the affected keyword in the trigger code.

2025-04-10 comment 0  967

Course Introduction：SQL triggers are database objects that automatically perform operations when a specific event occurs. Create a trigger consists of the following steps: Select the trigger type: BEFORE, AFTER, or INSTEAD OF Specify the trigger event: INSERT, UPDATE, or DELETE Write the trigger code, specifying the operation to be performed to create the trigger using the CREATE TRIGGER statement.

2025-04-10 comment 0  765

Course Introduction：Debugging Ineffective MySQL Trigger: Understanding Stored Function/Trigger RestrictionsEncountering an unresponsive MySQL trigger can be...

2024-11-06 comment 0  971

Course Introduction：Oracle triggers are database objects that execute business rules or actions when a specific event, such as insertion, update, or delete, occur. Creating a trigger requires the following steps: 1. Create a trigger, specifying the name, event, table, and FOR EACH ROW; 2. Write trigger code, performing verification, recording, calling stored procedures, etc.; 3. Specify the trigger timing (BEFORE, AFTER, or INSTEAD OF); 4. Compile the trigger.

2025-04-11 comment 0  706

Course Elementary  13955

Course Introduction：Scala Tutorial Scala is a multi-paradigm programming language, designed to integrate various features of object-oriented programming and functional programming.

Course Elementary  82523

Course Introduction："CSS Online Manual" is the official CSS online reference manual. This CSS online development manual contains various CSS properties, definitions, usage methods, example operations, etc. It is an indispensable online query manual for WEB programming learners and developers! CSS: Cascading Style Sheets (English full name: Cascading Style Sheets) is an application used to express HTML (Standard Universal Markup Language).

Course Elementary  13294

Course Introduction：SVG is a markup language for vector graphics in HTML5. It maintains powerful drawing capabilities and at the same time has a very high-end interface to operate graphics by directly operating Dom nodes. This "SVG Tutorial" is intended to allow students to master the SVG language and some of its corresponding APIs, combined with the knowledge of 2D drawing, so that students can render and control complex graphics on the page.

Course Elementary  24774

Course Introduction：In the "AngularJS Chinese Reference Manual", AngularJS extends HTML with new attributes and expressions. AngularJS can build a single page application (SPAs: Single Page Applications). AngularJS is very easy to learn.

Course Elementary  27599

Course Introduction：Go is a new language, a concurrent, garbage-collected, fast-compiled language. It can compile a large Go program in a few seconds on a single computer. Go provides a model for software construction that makes dependency analysis easier and avoids most C-style include files and library headers. Go is a statically typed language, and its type system has no hierarchy. Therefore users do not need to spend time defining relationships between types, which feels more lightweight than typical object-oriented languages. Go is a completely garbage-collected language and provides basic support for concurrent execution and communication. By its design, Go is intended to provide a method for constructing system software on multi-core machines.