Query Fails When Returning A Single Record With Numeric Data In NVarChar(16) Column In Device App

If a Select is done on a column whose data type is nvarchar(16) and contains only numerals (UPC numbers) the select does not return the record.

1. Query with numerals in nvarchar column works as long as multiple records are returned (LIKE '012%')
2. Numeric (INT only one tested) columns works as expected
3. String columns with alpha data works as expected
4. Problem only exist when running in Device Emulator and/or actual device.
5. Same test on desktop app runs as expected.
6. Windows Mobile 6, Vista Ultimate
7. Same results when when connection to device from SSMS
8. SQL Servers comes on

Previous thread discussion of this problem (I thought that Parameters corrected problem, but not in all cases???)

http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.sqlserver.ce&mid=0cd9cd3a-f9b0-477f-b1e7-c27eb76158ae

Here is the complete code:


SqlCeConnection _conn = null;

_conn = new SqlCeConnection(@"Data Source=program FilesTestResultSetevsoft.sdf;");

_conn.Open();


// DOES NOT WORK *** This statement does not return the record (it exist)

string _sql = "SELECT * FROM Product where RegDescr='0123456' ";




// works correctly

string _sql = "SELECT * FROM PRODUCT where ProdNum = 6523 ";


// works correctly *** as long as multiple records are returned

string _sql = "SELECT * FROM PRODUCT where RegDescr LIKE '01%' ";

// works correctly


string _sql = "SELECT * FROM PRODUCT where RegDescr='BACARDI SILVER RAZZ'";

SqlCeCommand _cmd = _conn.CreateCommand();

SqlCeDataReader _rdr;

_cmd.CommandText = _sql;

_cmd.CommandType = CommandType.Text;

// Same results using ExecuteResultSet or ExecuteReader

//_rdr = _cmd.ExecuteResultSet(ResultSetOptions.Scrollable | ResultSetOptions.Updatable);

_rdr = _cmd.ExecuteReader();



listBox1.Items.Add("In the while loop");

while (_rdr.Read())

{

listBox1.Items.Add(_rdr.GetValue(1) + " / " + _rdr.GetValue(3));

}

listBox1.Items.Add("Done");