Cannot use UPDATE with OUTPUT clause when a trigger is on the table

Why OUTPUT and Triggers Don't Play Nice Together

When a trigger fires up, the OUTPUT clause's results can flake out. Simply put, any attempts to capture pre-trigger state via the OUTPUT clause could backfire, leading to race conditions, data inconsistency, and a lot of scratching heads.

Using the Execute-and-Scan Strategy: SELECT after UPDATE

If you're dealing with potential OUTPUT problems, don't fret. Just perform a SELECT right after the update. This ensures you get the final row state - post-trigger meddling included:

UPDATE TargetTable
SET ColumnToBeUpdated = NewValue  -- Yep, another magic spell here
WHERE YourCondition;

SELECT ColumnToBeUpdated FROM TargetTable WHERE YourCondition;  -- Hey you, final row state, show yourself!
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Good news? Even Entity Framework (EF) Core 7.0 learns lessons from this strategy. So remember to specify trigger handling when configuring your EF entities in OnModelCreating().

Introducing an All-Rounder: The Transaction

Wrap your UPDATE operation in atomic transactions, winning both concurrency control and data consistency:

BEGIN TRANSACTION

-- The usual UPDATE operation with OUTPUT tucked safely into the table variable

COMMIT TRANSACTION  -- And... scene!
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Plan B: Trusty Stored Procedures

Avoid the complex tango between OUTPUT and triggers by using mighty stored procedures. These stored operations perform updates and then return results - no trigger conflicts in sight.

Playing Defense: Anticipating and Managing Trigger Side Effects

When dealing with triggers, be prepared:

• Inspect Strings: Audit your triggers beforehand to get insights into possible data alterations.
• False Friends: Avoid using @@identity during a trigger execution - it may just deceive you!
• Keeping up with EF Core: New EF Core versions may bring breaking changes affecting triggers. Stay updated with regular testing.
• Rely on Stored Procedures: Shields up and trigger-OUTPUT conflicts down!

Diving Deeper: Concise Q&A for Real-world Scenarios

How to handle concurrency?

Avoid race conditions and ensure data integrity:

• Use Transactions: Provide atomic operations that maintain data consistency and prevent race conditions.
• Limit Data: Store only the essentials in the table variable for effective operation.
• Use Locking Hints: Spotted concurrent operations? Control them using locking hints.

Stuck with complex trigger and OUTPUT interactions?

Here are some lifelines:

• Expert Consultation: Seek guidance from seasoned database professionals.
• Community Learning: Engage in programming communities, discussions, and knowledge sharing platforms.
• Stay Updated: Regularly follow authoritative resources and documentation. Trust me, they're goldmines.