Predicates

Notes:

• These apply to any data types that are naturally comparable: numbers, strings, date-times, durations, etc.

• XTDB predicates all use three-valued logic, as per the SQL spec - unless otherwise specified, if any input expression is null, the result will also be null.

The standard comparators are available:

• expr1 < expr2 (less than)

• expr1 <= expr2 (less than or equal to)

• expr1 > expr2 (greater than)

• expr1 >= expr2 (greater than or equal to)

• expr1 = expr2 (equal to)

• expr1 <> expr2 | expr1 != expr2 (not equal to)

Greatest / Least

These aren’t strictly predicates - they return the greatest/least value of their arguments respectively:

GREATEST(expr, ...)

returns the greatest value of the provided arguments, by the usual comparison operators

LEAST(expr, ...)

returns the least value of the provided arguments, by the usual comparison operators

Boolean functions

expr1 AND expr2

returns true if both expr1 and expr2 are true, false otherwise

expr1 OR expr2

returns true if either expr1 or expr2 are true, false otherwise

NOT expr

returns true if expr is false, false otherwise

expr IS [NOT] TRUE

returns true if expr is [not] true, false otherwise (including if expr is null)

expr IS [NOT] FALSE

returns true if expr is [not] false, false otherwise (including if expr is null)

expr IS [NOT] NULL

returns true if expr is [not] null, false otherwise