This topic describes the comparison functions that are supported by PolarDB-X 1.0.

The following table describes the comparison functions that are supported by PolarDB-X 1.0.

Function Description
COALESCE() Return the first non-NULL argument
GREATEST() Return the largest argument
IN() Check whether a value is within a set of values
INTERVAL() Return the index of the argument that is less than the first argument
ISNULL() Test whether the argument is NULL
LEAST() Return the smallest argument
NOT IN() Check whether a value is not within a set of values
STRCMP() Compare two strings