Table Writes

Reject a Duplicate Insert

Duplicate keys are rejected visibly.

highlighted = computed this step

Reject a duplicate insert

An INSERT is rejected when its key already exists.

duplicate key is rejected\text{duplicate key is rejected}

Show the rejection

Rejected writes are 1, and final rows stay 3.

rejected=1\text{rejected}=1

Write examples are tiny finite row modifications; SQL dialects, transactions, constraints beyond the visible key, triggers, indexes, concurrency, performance, and product behavior are out of scope.

Reject a duplicate insert: base tableidnamepoints1Ada102Ben203Cy15 writes in orderstepkindkeydetail0insert2[2, Bea, 30] write resultsstepkindkeystatusreasonbeforeafter0insert2rejectedduplicate_key33 final tableidnamepoints1Ada102Ben203Cy15 write factsfactvaluebaseRowCount3writeCount1appliedCount0rejectedCount1finalRowCount3keyColumnidrowOrderkey

Read the reason

The write result says duplicate_key, and the final table is unchanged.

reason is visible\text{reason is visible}

Summary

Duplicate-key failure is a computed write result, not a hidden edit.

no duplicate row added\text{no duplicate row added}