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1.1Why Query the Database Directly?
Every application has layers. A user clicks a button in the UI, which sends an HTTP request to the API, which executes business logic, which writes data to the database. Each layer can introduce bugs. The database is the final layer -- the source of truth.
Consider this scenario: a user creates an account through your web application. The UI shows "Account created successfully." The API returned HTTP 201. But did the data actually persist? Without querying the database, you are trusting every layer in between.
User Action UI Response API Response Database Reality
----------- ----------- ------------ ----------------
Click "Register" "Success!" 201 Created ???
The database is the only place to verify what ACTUALLY happened.