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Grade 10 · lesson 2 of 4

Maintain an Enforced Parent Reference

Verify the referenced parent exists under the stated enforced rule.

About 22 minutes, plus any extended practice

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Supplied materials

  • Paper and pencil; answers may also be spoken or typed.
  • All cases, labels, numbers and rules are supplied on this page. No real account, private information or purchase is needed.

Learn the idea

A foreign-key reference can link a child record to a parent under specified constraints. In the supplied model every child must reference an existing parent. Deleting a parent may need a defined reject, cascade or replacement policy; this model rejects missing references instead of guessing.

Verify the referenced parent exists under the stated enforced rule. A parent-looking code is not evidence that a corresponding parent record exists.

Use this supplied case: Child points to A. Parents A,B,C. Each child must reference an existing parent. Classify the child reference. The task is to connect the given information to the computing idea. Write a short evidence trail so another learner can reproduce your choice. The simplified case describes the stated model, not every real system.

  1. Represent the supplied worked case with a labeled drawing, table or short trace.
  2. Verify the referenced parent exists under the stated enforced rule.
  3. Explain why the worked answer fits and why one alternative does not.
  4. Try the new check and practice cases; revisit the stated rule if your evidence does not match.
Worked example

See the method in action

Child points to A. Parents A, B, C. Each child must reference an existing parent. Classify the child reference. The supported answer is Accepted parent reference. Verify the referenced parent exists under the stated enforced rule. A parent-looking code is not evidence that a corresponding parent record exists. The supplied facts, rather than an assumed real-world detail, determine this paper case. Compare the recorded action or value with the stated rule before choosing an answer.

Your turn

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Helpful tips
  • Verify the referenced parent exists under the stated enforced rule.
  • A parent-looking code is not evidence that a corresponding parent record exists.
Child points to D. Parents A,B,C. Each child must reference an existing parent. Classify the child reference.

Feedback appears here after you check. This is practice, not a graded school assessment.

See the answer and explanation

Missing referenced parent

The supplied case states: Child points to D. Parents A,B,C. Each child must reference an existing parent. Classify the child reference. Under the stated distinction, this identifies Missing referenced parent. A foreign-key reference can link a child record to a parent under specified constraints. In the supplied model every child must reference an existing parent. Deleting a parent may need a defined reject, cascade or replacement policy; this model rejects missing references instead of guessing. Verify the referenced parent exists under the stated enforced rule.

Take it further

Parents P, Q and child parent R fail the stated existing-parent requirement. If reference enforcement is disabled, the declared intention alone does not prove rejection.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.

More practice: try new cases

Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.

More practice: try new cases
1. Child parent field is blank. 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.
2. No reference rule is supplied for another table. 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. Child points to C. 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.

Your choices are temporary. Feedback appears after you check all the answers.

Nothing here is saved to an account or sent to a teacher. Keep your own notes or download them before leaving. The score describes these questions; it does not certify subject mastery.

Check the subject sources

These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.