Nullable fields cause pointer addresses to be printed

[patrickpichler]

Describe the bug When querying a table with nullable fields in clickhouse (postgres doesn't have this behavior), the result prints the pointer address instead of the value. After some debugging it looks like clickhouse is using pointer types to represent nullability.

To Reproduce Steps to reproduce the behavior:

1. Setup a clickhouse instance
2. Create a table with a nullable column
3. Insert data into table
4. Select table (you will now see pointer addresses instead of the values)

Expected behavior Pointers should be resolved, if they are not nil

Versions (please complete the following information):

• OS Version: MacOS
• sqls Version: master (eb695acda8a928f6633555fedb91b22e6290f0f0)