The Life Starter
Sign up
Grade 10 · unit review

Review: Design Consistent Relational Records

Design parentsA,B and children with required parent IDs. Evaluate a child pointing to C, an incomplete 3-token transfer and a query with a user-supplied value.

Download reviews and answer keys

Bring the unit skills together

Use these 4 new cases to check your reasoning. Choices are temporary and are not saved to an account, sent to staff or recorded as school grades. Download your current review choices before leaving or reloading.

Unit review questions
1. Two supplied rows both have item_id=G. The primary key item_id is required unique. Which constraint outcome follows?
Need a hint?
  • Use the explicit input, condition and question aspect.
  • Reject a choice that adds an unsupported condition or answers a different question.
2. Child points to E. Parents A,B,C. Each child must reference an existing parent. Classify the child reference.
Need a hint?
  • Verify the referenced parent exists under the stated enforced rule.
  • A parent-looking code is not evidence that a corresponding parent record exists.
3. First update succeeds but second is missing. Atomic model moves 3 tokens from A to B. Classify the recorded outcome.
Need a hint?
  • Commit the complete valid change or roll back the incomplete change.
  • Two successful-looking partial steps are not enough if their combined invariant is broken.
4. Untrusted text becomes part of the constructed command. Which query-plan property is described?
Need a hint?
  • Bind the supplied input as a data parameter and keep allowed query structure fixed.
  • Escaping by guesswork is not a substitute for documented parameter binding.

The download contains your current choices and any checked feedback. Keep the separate transfer-task work in your own document; downloading its instructions does not mark it complete.

Use the skills in a new task

Design parentsA,B and children with required parent IDs. Evaluate a child pointing to C, an incomplete 3-token transfer and a query with a user-supplied value.

Work on paper or in your own document. Explain the choices you made.

  • Use only supplied fictional inputs and state the relevant rule.
  • Include labeled steps or evidence for each decision.
  • Name one limitation or tempting mistake.
  • Check that the result meets the task and revise a justified error.
Compare with a model response

C is absent, so the enforced reference rule rejects that child. An incomplete atomic transfer rolls back rather than keeping only the debit. The query binds its input as a data parameter, keeping permitted structure separate.

A different response can also meet the criteria. Compare the evidence and reasoning, rather than copying the wording.