Oracle Database 19c: SQL Workshop — Lesson 3: Subqueries, Set Operators, DML, and Transactions

Technical Scope

• single-row, multi-row, and correlated subqueries
• EXISTS, NOT EXISTS, and scalar queries
• UNION, INTERSECT, and MINUS
• INSERT, UPDATE, DELETE, COMMIT, ROLLBACK, and savepoints

Instructor Demonstration

Demonstrate single-row, multi-row, and correlated subqueries inside a sales-and-staffing schema where every query must include an expected result, row-count check, and edge case, then capture the exact configuration, command, transaction, report, or code evidence that proves the result.

Applied Workshop

Implement a controlled workshop covering EXISTS, NOT EXISTS, and scalar queries and UNION, INTERSECT, and MINUS, then test a failure or exception involving INSERT, UPDATE, DELETE, COMMIT, ROLLBACK, and savepoints.

1. Confirm environment, identity, data, dependencies, and expected result.
2. Complete the product-specific implementation or analysis.
3. Capture commands, configuration, output, logs, transactions, or reports.
4. Explain the operational, security, performance, or business trade-off.

Validation Standard

The Subqueries, Set Operators, DML, and Transactions result must be reproducible, traceable to approved inputs, and consistent with the expected Oracle product behavior.

• The intended target and ownership are verified.
• The result is supported by reproducible evidence.
• Security, performance, reliability, and support impact are reviewed.
• Unexpected behavior is investigated before acceptance.

Failure Analysis

Diagnose issues in single-row, multi-row, and correlated subqueries, EXISTS, NOT EXISTS, and scalar queries, UNION, INTERSECT, and MINUS, or INSERT, UPDATE, DELETE, COMMIT, ROLLBACK, and savepoints without making an unverified production change.

Learners isolate the smallest proven cause, apply a reversible correction, rerun validation, and record the preventive action.