Delete query or checking for the record first before deleting

It generally depends on the specific use case, but here are some considerations to help you decide between directly executing the delete query or checking for the record first before deleting:

1. Directly Executing the Deletion Query

• Pros:
• Efficient: You avoid an extra database round-trip to check if the record exists, which can improve performance, especially when dealing with large data sets or frequent deletes.
• Simpler Code: You eliminate the need for an additional query to check for existence.
• Atomicity: The delete operation is executed in a single step, reducing the chance of race conditions (where another operation could potentially modify the data between the check and the delete).
• Cons:
• No Feedback: If you need to provide feedback about whether a record was actually deleted or not, this method doesn’t explicitly check that.
• Unnecessary Deletes: If you attempt to delete a record that doesn’t exist, it can result in a “soft-failure” where no record is found, but the system continues without issue. This might be fine in some cases, but could be an issue if you’re relying on it to detect or log non-existent records.

2. Checking for the Record First, Then Deleting

• Pros:
• More Control: You can handle scenarios where the record doesn’t exist (e.g., logging, returning a specific message to the user, etc.).
• Feedback: It allows you to return more meaningful responses to the calling code, like “Record not found,” which might be important in some applications.
• Complex Logic: If you have additional business logic that needs to be executed when a record exists (e.g., checking permissions), it can be beneficial to check the existence first.
• Cons:
• Less Efficient: This introduces an extra database query (to check for the record) and could reduce performance, especially when performing bulk deletes or when the check is not strictly necessary.
• Potential Race Conditions: Between the check and delete operation, the record might change or get deleted by another process. This could lead to inconsistent behavior.

Best Practice:

For most applications, directly executing the delete query is the better choice in terms of performance and simplicity, especially if:

• You don’t need to provide feedback about the existence of the record before deletion.
• You want to avoid an extra database round-trip.
• The deletion operation is safe, and the database handles concurrency well.

If you do need more control (such as logging, error handling, or complex conditions), then checking first might be preferable.

Recommendation:

• For performance-critical systems: Directly execute the delete.
• For scenarios requiring validation or business rules: Check first, then delete.