Casting from Variant into Other types.

[BohuTANG]

Summary

Table:

 CREATE TABLE `json_test` (
  `a` Variant,
)


insert into json_test values('{"aa":1,"aA":2,"Aa":3}');

Query:

select sum(get(a, 'aa'))  from json_test;

Error:

AggregateSumFunction does not support type 'Variant' (while in select group by)

[sundy-li]

You can use cast function to apply sum.

select sum(get(a, 'aa')::UInt64)  from json_test;

[BohuTANG]

mysql> select sum(get(a, 'aa')::UInt64)  from json_test;
ERROR 1105 (HY000): Code: 1002, displayText = Not yet implemented: Casting from Extension("Variant", LargeBinary, None) to UInt64 not supported (while in processor thread 35).

[sundy-li]

Ok, then let's fix this bug: casting from Variant into Other types.