Day 19
Quiz
| 1: | What can triggers be used to enforce? |
| A1: | A trigger can be used to enforce the following in a database: data integrity, referential integrity, and business rules. In addition, triggers can be used to maintain derived columns, logs, and audit trails. |
| 2: | How many levels of nested triggers are allowed? |
| A2: | You can nest triggers up to a maximum of 32. |
| 3: | What happens when a statement in a trigger fails? |
| A3: | Whenever a statement in a trigger fails, the transaction that caused the trigger to fire will be rolled back. |
Exercise
| 1: | Using the Northwind database, create a trigger that prevents you from adding a new product without having a valid supplier. |
| A1: |
Create Trigger tr_Prod_Supplier On Products For Insert As If (Select Count(*) From Inserted ... |
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