Unverified50% confidenceFactExact time
In PostgreSQL, SELECT NULL = NULL returns NULL rather than TRUE.
1
Sources
50%
Confidence
Long-term
Relevance
9/12/2026
First Seen
Sources
Related Entities
Related Claims
UnverifiedPostgreSQL treats NULL as the largest value by default, placing it at the end in ascending order and at the beginning in descending order.74% similarUnverifiedPostgreSQL's aggregate functions ignore NULL values: COUNT(*) counts all rows, while COUNT(val), SUM, and AVG ignore NULL values.73% similarUnverifiedIn SQL's three-valued logic, the result of any comparison operation involving NULL is UNKNOWN, rather than TRUE or FALSE.69% similarUnverifiedIf the result of a NOT IN subquery contains any NULL, the entire query returns an empty set; therefore, using NOT EXISTS instead is recommended.68% similarUnverifiedMySQL和PostgreSQL在无法完成类型转换时会抛出错误，而SQLite默认策略是永不失败63% similar
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