Re: Report BUG: The column size for BIT VARYING(5) type is incorrect

"Clemens Ladisch" <clemens(at)ladisch(dot)de> wrote on 08/26/2020 03:01:20 AM:
> > Why is the *ColumnSizePtr = 1 instead of *ColumnSizePtr = 5 since
> the column is created with bit varying (5) in the test case?
>
> The ODBC specification does not define the data type BIT VARYING, so the
> ODBC driver tries to represent it as a blob or text.
>
> And five bits fit into one byte.

I'm not sure this is the correct interpretation. According to PostgreSQL,
bit varying(n) is a bit "string" (
https://www.postgresql.org/docs/12/datatype-bit.html) The ODBC spec says
that the column size for all string types is defined as the "... maximum
column size in characters of the column or parameter" (
https://docs.microsoft.com/en-us/sql/odbc/reference/appendixes/column-size
). Also, according to the bug report, SQLDescribeCol answered that the
data type in this case was returned as SQL_WVARRCHAR.

I don't use this type myself but based on the documentation and the
(fact?) SQLDescribeCol answers the type as SQL_WVARCHAR, it does make
sense to me for the column size to match the number of characters needed
to represent the bits.

Jon