OLEDB Jet 4.0 SQL Character Limit - sql

Question

I am attempting to generate lines for an SDF (Space Delimited File). I am creating these lines from a DBASE IV DBF file using an OLEDB adapter with extended properties DBASEIV to get at the data. My data column output is 425 characters long after padding, I am placing this into a datagridview in VB.NET to display it.
However when I run my query, while it seems to execute correctly the resultant field is restricted to 256 characters. The longest individual field I am reading is 35 characters and I am returning a dataset with 2 fields, the barcode and the SDF line. As I understand it OLEDB Jet 4.0 tries to guess the type based on the first 8 rows, however as all rows are equal length for the data column (425 chars) I don't get why it is choosing the smaller field type. I assume it is because my field is a generated one using string concatenation. I have included the horrible SQL at the bottom of this question. So my question is how can I get the full 425 character output? Or is there a way I can specify the datatype for my own field as memo?
SELECT scan,
RIGHT('0000000000000' + trim(cstr(scan)), 13) +
LEFT(trim(cstr(name)) + ' ', 35) +
LEFT(trim(cstr(name)) + ' ', 16) +
' ' +
' ' +
' ' +
'1 ' +
'0.00 ' +
'0.00 ' +
'1' +
'0.00 ' +
'0.01 ' +
'0.00 ' +
'F' +
'2' +
'0.00 ' +
'0.00 ' +
' ' +
' ' +
' ' +
'SALS' +
' ' +
' ' +
LEFT(trim(cstr(plof)) + ' ', 13) +
' ' +
' ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'F' +
'T' +
'001' +
' ' +
'T' +
'01' +
' ' +
' ' +
' ' +
' ' +
'F' +
'F' +
' ' +
' ' +
'0 ' +
'0.00 ' +
' ' +
'0 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'1 ' +
'1 ' +
'1 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
'0.00 ' +
' ' +
' ' +
' '
as STTEMPLINE
from salus where cstr(scan) in (select distinct cstr(scan) from nonscan)
Thanks in advance for any help.

Answer 1

This is a known issue where data types are guessed based on data in the first few rows.
See this post...
Load Excel sheet into DataTable but only the first 256 chars per cell are imported,
Also, see this post for an explanation of how OLEDB deals with mixed data types...
http://social.msdn.microsoft.com/Forums/pl-PL/csharplanguage/thread/0404d003-5bfb-44f9-8e6b-aebdfce24875