SQL triggers are automated procedures that execute in response to database events like INSERT and UPDATE operations. They play a crucial role in maintaining data integrity, enforcing business logic, and automating repetitive tasks. Triggers can be used for tasks such as generating audit records or synchronizing data across tables, which is essential in complex systems like banking. Understanding their syntax, structure, and best practices is key to effective database management.
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SQL triggers are specialized procedures that automatically execute in response to certain events on a database table, such as INSERT, UPDATE, or DELETE operations, and are essential for preserving data integrity and automating repetitive tasks
After INSERT Triggers
After INSERT triggers execute after a new row is added to a table and can be used for validating data or cascading changes to other tables
After UPDATE Triggers
After UPDATE triggers are invoked after a row is modified and are used to track changes or propagate updates within the database
SQL triggers are created using a specific syntax that defines the event, timing, and execution conditions, allowing for precise configuration of their operation
To ensure SQL triggers are effective and do not hinder database performance, it is crucial to adhere to best practices such as creating concise and purposeful triggers, using clear and descriptive names, and minimizing their number
Rigorous testing and thorough documentation of trigger code are essential for maintaining trigger reliability and contributing to the overall efficiency of the database system
An After INSERT trigger can be used to automatically log each new sale into a 'SalesHistory' table for audit purposes
An After UPDATE trigger can be used to monitor salary adjustments in an 'Employee' table by documenting the old and new salary figures in a 'SalaryHistory' table
Oracle SQL uses sequences to generate unique values and employs pseudorecords to capture changes in an After UPDATE trigger
While the underlying concepts of triggers are consistent, the implementation can differ based on the database platform, such as in Oracle SQL
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In a ______ system, a trigger might log each account transaction to maintain accurate and traceable financial data.
banking
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Purpose of After INSERT Trigger
Executes post-row addition for data validation or cascading changes to other tables.
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Function of After UPDATE Trigger
Invoked post-row modification to track changes or propagate updates, ensuring data integrity.
