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#include <Functions/isNotDistinctFrom.h>
namespace DB
{
REGISTER_FUNCTION(IsNotDistinctFrom)
{
factory.registerFunction<FunctionIsNotDistinctFrom>(
FunctionDocumentation{
.description = R"(
Performs a null-safe comparison between two values. This function will consider
two `NULL` values as identical and will return `true`, which is distinct from the usual
equals behavior where comparing two `NULL` values would return `NULL`.
Currently, this function can only be used in the `JOIN ON` section of a query.
[example:join_on_is_not_distinct_from]
)",
.examples{
{"join_on_is_not_distinct_from", "SELECT * FROM (SELECT NULL AS a) AS t1 JOIN (SELECT NULL AS b) AS t2 ON isNotDistinctFrom(t1.a, t2.b)", "NULL\tNULL"},
},
.categories = {"Comparison", "Join Operators"},
});
}
}
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