Hello, all Contributors to apache calcite:
I am facing a throny issue on calcite-1.38.0, when use the sql
following:
```sql```
Select string_10_fun
from (
select string_10_fun
from (
select string_10_fun
from (
select string_10_fun
from (
select char_length(string_10) as
string_10_fun
from table
order by double_01
)
)
order by string_10_fun
)
order by string_10_fun
)
order by string_10_fun
```
At this point, the query executed to Druid generates a result, which
column name is string_10_fun, is valued type DruidType.Long, However, in the
method where the physical plan is generated, the sort function’s parameter
string_10, as the same name as char_length(string_10), is defined as an integer
type ( which definition is in
core/org/apache/calcite/sql/fun/SqlStdOperatorTable.java). Since Java does not
allow automatic conversion from a higher precision type long to a lower type
integer, the result returned by Druid(type long) cannot be used as a valid
parameter to sort and causing an error.
To fix this question, I tried to change the
SqlStdOperatorTable.char_length to ReturnTypes.BIGINT_NULLABLE, but it will
cause a series of new question, such as function lpad and function road. Both
of them are supported to use Type integer as the second parameter but not long.
If the result of char_length need to be used as lpad or rpad. It will also
causing errors.
I was wonder that if there are any solution could help solving this
thorny issue.
Thanks for your reading!
