LIKE Patterns

Exact Literal Pattern

A pattern with no wildcard must match exactly.

highlighted = computed this step

Exact literal pattern

A pattern with no wildcard must match the whole string exactly.

literal match\text{literal match}

Read literal matches

The literal pattern matches 1 row.

TRUE rows=1\text{TRUE rows}=1

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.

Exact literal pattern: base rowsidname1Ada2Al3Alan4Bea5Jo6NULL LIKE evaluationsourcevaluepatterntruthkept0AdaAdaTRUEyes1AlAdaFALSEno2AlanAdaFALSEno3BeaAdaFALSEno4JoAdaFALSEno5NULLAdaUNKNOWNno LIKE output rowsidname1Ada LIKE factsfactvalueinputRowCount6outputRowCount1trueRows1falseRows4unknownRows1patternKindliteralrowOrdersource_order

Whole string

Ada matches Ada; Al and Alan do not match the whole literal.

whole string\text{whole string}

Summary

Without wildcards, LIKE is an exact string match here.

exact literal\text{exact literal}