Re: OLEDB errors when updating rows (that contain BLO B columns) using dynamic accessor

Hi Mark,
Yes, I am trying to leave the BLOB column unchanged during the SetData call
(e.g. I decided I want to change only some non BLOB data).

I have come up with the following pattern:
1. In BindColumns override (CDynamicAccessor) after binding I would set
DBSTATUS_S_IGNORE on all BLOB columns.
2. If I would then change some BLOB data, I'd set that column's status to
DBSTATUS_S_OK.
3. I wouldn't NULL all stream ptrs that I haven't used, because of the
ignore status set shortly after the binding, provider would not free them
after SetData (and that accessor freeing Release would work).

Unfortunately, DBSTATUS_S_IGNORE does not work for me. I always get that
E_UNEXPECTED (0x8000ffff) after calling SetData (although I have previously
explicitly set BLOB column status to ignore).

Well, my conclusion in a chronically time shortage, is following:
1. If I do not need BLOB column in my recordset, I will not include that
column in my SELECT (that's pretty obvious).
2. If I however bind some BLOB columns with my SELECT, before
updating/inserting, I would read/write that data stream (I would definitely
take ownership of stream), if I have not previously touched it. It is
costly but why did anyone bind BLOB if he/she did not need it in a first
place?

Orest Kulik
Ekobit, HR

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