[ENH] Support user control over case sensitivity

Some SQL query generators make it difficult to control the upper/lower cases of columns, tables, etc in emitted SQL.

In my use case, I’m trying to avoid modifying a query that uses uppercase column names, where my table was defined w/ lower case column names. It’d be useful to allow a configuration of case sensitivity used in the SQL parsing step. It looks like this is doable in Calcite.

Test:

from dask_sql import Context
import pandas as pd

c = Context()
df = pd.DataFrame({'id': [0, 1]})

c.create_table('test', df)
c.sql("select ID from test")

Trace:

---------------------------------------------------------------------------
ParsingException                          Traceback (most recent call last)
/tmp/ipykernel_574321/308482520.py in <module>
      4 df = cudf.DataFrame({'id': [0, 1]})
      5 c.create_table('test', df)
----> 6 c.sql("select ID from test")

~/conda/envs/dsql-dask-main/lib/python3.8/site-packages/dask_sql/context.py in sql(self, sql, return_futures, dataframes)
    434                 self.create_table(df_name, df)
    435 
--> 436         rel, select_names, _ = self._get_ral(sql)
    437 
    438         dc = RelConverter.convert(rel, context=self)

~/conda/envs/dsql-dask-main/lib/python3.8/site-packages/dask_sql/context.py in _get_ral(self, sql)
    772             # if debug is not set.
    773             # Instead, we raise a nice exception
--> 774             raise ParsingException(sql, str(e.message())) from None
    775 
    776         # Internal, temporary results of calcite are sometimes

ParsingException: Can not parse the given SQL: org.apache.calcite.runtime.CalciteContextException: From line 1, column 8 to line 1, column 9: Column 'ID' not found in any table; did you mean 'id'?

The problem is probably somewhere here:

	select ID from test
	       ^^

[charlesbluca]

Yeah can verify that the following works for me with the latest dask-sql:

from dask_sql import Context
import pandas as pd

c = Context()
c.set_config(("dask.sql.identifier.case.sensitive", False))
df = pd.DataFrame({'id': [0, 1]})

c.create_table('test', df)
c.sql("select ID from test")

[jdye64]

@randerzander are you sure you are using the correct version in your tests? This seems to works and is tested in https://github.com/dask-contrib/dask-sql/blob/main/tests/integration/test_compatibility.py#L940