"Clemens Ladisch" <clemens@ladisch.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.
