Can I use… T151, “DISTINCT predicate”

1. Not for row-values
2. Supports the non-standard spaceship operator instead: <=>

Related

• T152, “DISTINCT predicate with negation”

• Tutorials:

  • NULL-Aware Comparison: is [not] distinct from

  • NULL in SQL: Indicating the Absence of Data

  • The Three-Valued Logic of SQL

Normative References

The optional feature T151, “DISTINCT predicate” is defined in ISO/IEC 9075-2:2016. It first appeared in 1999.