Comparison Predicates

Not-equal Matches

Not-equal keeps known different values.

highlighted = computed this step

Not-equal matches

Not-equal keeps known values that are different from pinned value 7.

qty≠7\text{qty}\ne 7

Read different rows

There are 2 TRUE rows and 1 UNKNOWN row.

TRUE rows=2\text{TRUE rows}=2

Comparison examples are tiny finite-table transforms with SQL-style TRUE/FALSE/UNKNOWN results; SQL dialect completeness, type coercion, optimizer behavior, indexing, and product claims are out of scope.

Not-equal matches: base rowsidnameqtycity1alpha3Austin2beta7Boston3gamma7NULL4delta10Denver5epsilonNULLAustin Comparison result per rowsourceleftValueoprightValuetruthoutputRole03ne7TRUEkept17ne7FALSEdropped27ne7FALSEdropped310ne7TRUEkept4NULLne7UNKNOWNdropped WHERE-style TRUE-only output rowsidnameqtycity1alpha3Austin4delta10Denver Comparison factsfactvalueinputRowCount5trueCount2falseCount2unknownCount1outputRowCount2droppedRowCount3orderedComparisonnowhereKeepsTRUE_only_source_order

NULL is not TRUE

A NULL comparison is UNKNOWN, not a not-equal TRUE match.

NULL→UNKNOWN\text{NULL}\to\text{UNKNOWN}

Summary

Not-equal still follows WHERE-style TRUE-only output.

TRUE only\text{TRUE only}