ODBC: How to bind a empty string to null in c++

Question

Odbc returns empty string instead of null . I have used SQLBindParameter which binds the values.How to get Null values instead of empty string (blank).

Answer 1

Here is an example:

    SQLINTEGER sqllen = 0;
    SQLCHAR buf[255] = { 0 };

    while ((retcode = SQLFetch(_hstmt)) != SQL_NO_DATA)
    {
        if (SQLGetData(_hstmt, 1, SQL_C_CHAR, &buf[0], sizeof buf + 1, &sqllen) == SQL_NULL_DATA)
        {
            this_is_your_string = nullptr;
        }
    }

This makes the string have a nullptr value, this is C++ 11. Also see this post