Wrong number of fields with grouparray via ODBC

Hi,

The following statement should give a list of fields per table:
```
SELECT
table AS table_name
, REPLACE(REPLACE(REPLACE(toString(groupArray(name)), '[',''), ']',''), '''', '') AS fieldlist
FROM system.columns
GROUP BY table
```
In DB Visualizer or native, we get the correct number of entries in the fieldlist (our test table has 367 fields), but with ODBC, we receive much more fields (some of them are listed twice or even more).