How to Debug SQL Errors with AI Quiz

Answers and explanations appear as you take the quiz.

1. Two joined tables both contain id, and the intended output is the customer's identifier. Which repair addresses the ambiguity?
   • Qualify id with the customer table's alias
   • Choose either id because matching names imply identical values
   • Add every column to GROUP BY
   • Rename the output heading without qualifying the reference
2. Why can adding every selected column to GROUP BY be a poor repair for a customer-total report?
   • It guarantees that all selected dates belong to the same customer summary
   • It preserves customer-level totals regardless of the added columns
   • It may change the result from one row per customer to a finer grouping
   • It automatically chooses the latest order date within each customer
3. An error points near the end of an expression. Why should earlier tokens also be inspected?
   • The marked token must always be the first incorrect token
   • Only the final clause can affect parsing near the end
   • Name-resolution errors can always be fixed by moving the marked token
   • An earlier missing comma or unmatched parenthesis can make a later token unexpected
4. Which information is most useful when asking AI to reproduce an SQL failure?
   • The query and a paraphrase of the error, without identifying the engine
   • The engine, exact error, query, minimal schema and representative test rows
   • Only a successful version from another database engine
   • Only the expected output, without the query or schema
5. A repaired SQL statement executes successfully. Which check still matters?
   • Whether its rows, totals and null behavior match the intended result
   • Whether it returns the same row count, without checking values
   • Whether it has the same output headings, without checking totals
   • Whether it runs once without an error on an empty fixture
6. A cast succeeds for most rows but fails for one unexpected text value. Which debugging step targets that failure?
   • Remove the type information from the prompt
   • Assume the query is syntactically invalid in every context
   • Include the failing value in a reduced test fixture
   • Add an unrelated join to change the execution plan
7. Why is PostgreSQL EXPLAIN ANALYZE inappropriate as a harmless syntax check for an untrusted modifying query?
   • It never reports actual execution behavior
   • It only checks table aliases
   • It always skips the statement's write operations
   • It actually executes the statement
8. An application query uses bound parameters. Why should a reproduction preserve their types?
   • Parameter types cannot affect a database operation
   • Substituted literals can behave differently from the original bound values
   • Every parameter should be converted to text before testing
   • A bound parameter always removes the need to check casts