I am using a DbDataReader to return the columns for a SQL SELECT statement. For the blob column, I am calling reader.GetOrdinal to get the column number, calling reader.GetBytes to get the size of the data, allocating the byte[], and then calling reader.GetBytes to read into the buffer.
Tim On Fri, May 6, 2011 at 11:12 AM, Robert Simpson <[email protected]> wrote: > How are you fetching the data? Are you using the generic reader[x] on a > datareader? Are you using a DataSet/DataTable? > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Tim Butterfield > Sent: Friday, May 06, 2011 8:58 AM > To: General Discussion of SQLite Database > Subject: Re: [sqlite] System.Data.SQLite blob column exception > > On Fri, May 6, 2011 at 7:44 AM, Simon Slavin <[email protected]> wrote: >> >> On 6 May 2011, at 3:43am, Tim Butterfield wrote: >> >>> The blob values are always inserted and read as a byte[]. If those >>> bytes are those of a text file, it fails. If I add a leading 0x00 >>> byte to force it to be binary, it works. >> >> Are you binding your parameters ? If so, check that you're using > sqlite3_bind_blob() when binding something to your BLOB column. Binding it > as text will not trigger an error, since SQLite is quite happy to bind text > into a BLOB column. But if you take blobby data, and bind it using > sqlite3_bind_blob() into a column defined as a BLOB SQLite should be > retaining and reporting it as as blob, not as text. >> >> If you're creating a fully text 'INSERT' or 'UPDATE' command rather than > binding parameters, them make sure you're using the correct format to > specify you have blob data (is it \x ?) rather than just supplying text. > > I'm using the System.Data.SQLite interface and not the direct C > interface methods. All of my inserts are done using DbParameter (@p1, > @p2, etc.) and DbCommand insert statements. The DbParameter.Value is > the C# object type. In the case of the blob column, that type is a C# > byte[], which sets the parameter type to DbType.Binary whether the > first byte is 0x00 or a more textual value. > > Tim > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- Tim Butterfield http://www.timbutterfield.com/ _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
