[Feature]: Support cast decimal as bigint

[domingozhang]

Is there an existing issue for the same bug?

• [X] I have checked the existing issues.

Environment

- Version or commit-id (e.g. v0.1.0 or 8b23a93):
- Hardware parameters:
- OS type:
- Others:

Actual Behavior

select cast(-19999999999999999999 as signed); Operator 'unary_minus' with parameters [VARCHAR] will be implemented in future version.

Expected Behavior

No response

Steps to Reproduce

No response

Additional information

No response

[domingozhang]

mysql> select cast(-19999999999999999999 as signed); ERROR 1105 (HY000): Operator 'cast' with parameters [DECIMAL128 BIGINT] will be implemented in future version.

@m-schen bigint to decimal128 seems not supported

[m-schen]

mysql> select cast(-19999999999999999999 as signed); ERROR 1105 (HY000): Operator 'cast' with parameters [DECIMAL128 BIGINT] will be implemented in future version.

@m-schen bigint to decimal128 seems not supported

we heve bigint -> decimal128 now. but not support decimal128 -> bigint at v0.5

[m-schen]

Track it with a new issue tag. we do not have decimal128 -> bigint now. but I'm no sure if we will fix it at version 0.6 @iamlinjunhong

[iamlinjunhong]

Doesn't support cast decimal as bigint now. Discuss with @domingozhang that will put this issue to 0.6.