A Guide to the SQL Standard¶
Date, C. J., & Darwen, H. (1997). A Guide to the SQL Standard. Addison-Wesley.
Cited by¶
1 citation across 1 artifact.
Each citation links to the sentence it supports in the citing article.
Primes¶
- Empty Set
- Empty versus unknown: SQL conflated these and has argued about it ever since — the empty set is known to be empty, while an unknown value is something else entirely.
This sourceDocuments SQL's conflation of empty (known-empty result) with NULL/unknown (value-not-determined) and the long-running three-valued-logic controversy it produced.
- Empty versus unknown: SQL conflated these and has argued about it ever since — the empty set is known to be empty, while an unknown value is something else entirely.
Verification¶
Does it exist? Not checked yet. This entry carries no identifier to resolve. It was extracted from the citation as written in the article, normalized, and deduplicated against the rest of the registry.
Does it back the claim? Not recorded. The single citation of this work carries no recorded support check.
Support is checked per citation rather than per work — the same source can be cited soundly in one article and wrongly in another. Per-citation recording began recently, so a citation with no recorded check is a gap in the record rather than evidence it went unchecked.
See how references were verified.
Registry ID ref:89049fb30db3 · see in the full table