LIKE Patterns

Honest by Construction

Expected LIKE facts are assertions only.

highlighted = computed this step

Honest by construction

Expected LIKE facts are assertions only.

compiler is source of truth\text{compiler is source of truth}

Render checked rows

The guarded LIKE filter renders 2 output rows after recomputation.

checked rows=2\text{checked rows}=2

LIKE-pattern examples are tiny finite WHERE-style filters with a small SQL-like pattern subset; collations, escapes, dialect behavior, indexes, optimizer behavior, and product claims are out of scope.

Honest by construction: base rowsidname1Ada2Al3Alan4Bea5Jo6NULL LIKE evaluationsourcevaluepatterntruthkept0AdaAl%FALSEno1AlAl%TRUEyes2AlanAl%TRUEyes3BeaAl%FALSEno4JoAl%FALSEno5NULLAl%UNKNOWNno LIKE output rowsidname2Al3Alan LIKE factsfactvalueinputRowCount6outputRowCount2trueRows2falseRows3unknownRows1patternKindpercentrowOrdersource_order

Try to tamper

Wrong expected facts, derived sidecars, missing columns, bools, floats, non-string LIKE inputs, and unsupported keys fail closed.

tamper rejected\text{tamper rejected}

Summary

The book shows exact finite LIKE behavior only; product SQL behavior is outside the model.

scoped LIKE model\text{scoped LIKE model}