fail to sql query if column contains capitalized letter

[hu6360567]

Describe the bug
fail to execute sql when select with column if the column contains capitalized letter

To Reproduce

import pyarrow as pa
import datafusion

if __name__ == "__main__":
    tbl = pa.Table.from_arrays([[1, 2, 3]], names=["id"])

    for column_name in ["id", "ID", "iD"]:
        ctx = datafusion.SessionContext()
        ctx.register_record_batches(name="tbl", partitions=[tbl.rename_columns([column_name]).to_batches()])

        sql = f"SELECT {column_name} from tbl"


        try:
            print(sql)
            ctx.sql(sql)
        except Exception as e:
            print(e)

SELECT id from tbl
SELECT ID from tbl
DataFusion error: SchemaError(FieldNotFound { field: Column { relation: None, name: "id" }, valid_fields: [Column { relation: Some(Bare { table: "tbl" }), name: "ID" }] })
SELECT iD from tbl
DataFusion error: SchemaError(FieldNotFound { field: Column { relation: None, name: "id" }, valid_fields: [Column { relation: Some(Bare { table: "tbl" }), name: "iD" }] })

Expected behavior
All sql should executed successfully.

Additional context
Python 3.8.16
pyarrow 12.0.0
datafusion 23.0.0

[hu6360567]

seems column name needs to be quoted. SELECT "ID" FROM tbl works as expected.

[mesejo]

If anyone else encounters a similar issue, they may find helpful information regarding this behavior by referring to the section Identifiers and Capitalization of DataFusion's documentation. Reproducing for completeness:

Please be aware that all identifiers are effectively made lower-case in SQL, so if your csv file has capital letters (ex: Name) you must put your column name in double quotes or the examples won’t work.

[timsaucer]

Closing because this is documented in the online site.