Neoview SQL Reference Manual (R2.4 SP2)

Null and Expression Evaluation Comparison
ResultConditionExpression Type
For AND, the result is null. For OR, the
result is true if the other operand is
true, or null if the other operand is null
or false. For NOT, the result is null.
Either operand is null.Boolean operators (AND, OR, NOT)
The result is null.Either or both operands are null.Arithmetic operators
The result is true.The operand is null.NULL predicate
The result is null if set is empty.Some rows have null columns.The
function is evaluated after eliminating
nulls.
Aggregate (or set) functions (except
COUNT)
The result is the number of rows in the
table whether or not the rows are null.
The function does not eliminate nulls.COUNT(*)
The result is zero if set is empty.The function is evaluated after
eliminating nulls.
COUNT COUNT DISTINCT
The result is null.Either operand is null.Comparison: =, <>, <, >, <=, >=, LIKE
The result is null if all of the
expressions are null.
Some expressions in the IN value list
are null.
IN predicate
The result is null.No rows are returned.Subquery
Null 271