How do you verify the results of a stored procedure or query? Methods and approaches.

Verifying the results of a stored procedure or query involves several approaches:

• Testing with known input data: run the procedure with pre-prepared parameters and compare the result with the expected outcome.
• Logging and debugging: add output of intermediate values or errors to the log to understand how the procedure works.
• Using EXPLAIN and execution plans: to assess query efficiency.
• Comparison with reference data: check that changes in the database match expectations.
• Automated tests: write unit tests for procedures if the DBMS supports it.

For example, you can execute the procedure and immediately perform a SELECT from the table it should modify to ensure that the data has been updated correctly.