C# Update single row in [my]sql

Question

Hi
We found after our Bugzilla upgrade that many comment records where not upgraded correctly due to special characters.
I have found all the old == good and matching new == bad records
Some of the comments can be up to 64k so I don't want to try to do this as a textual update, rather update the row directly
I am after hints how to do this ?
Thanks
try
adaptor = new OdbcDataAdapter(_query, _mySQL);
resultsTable = new DataTable("Results");
adaptor.Fill(resultsTable);
adaptorNew = new OdbcDataAdapter(_query, _mySQLNew);
resultsTableNew = new DataTable("Results");
adaptorNew.Fill(resultsTableNew);
//Console.WriteLine("Bug {0} has {1} comments", i, resultsTable.Rows.Count);
int rowCount = 0;
foreach (DataRow row in resultsTable.Rows)
DataRow newrow = resultsTableNew.Rows[rowCount];
// This checks the comments ids are the same if (row.ItemArray[1].ToString().Equals(newrow.ItemArray[1].ToString()))
// This checks the comments lengths
if (!row.ItemArray[2].ToString().Equals(newrow.ItemArray[2].ToString()))
Console.WriteLine("At id {0}, length differs {1} != {2}", i, row.ItemArray[2].ToString(), newrow.ItemArray[2].ToString());
// To DO - update new record with old record data
// xxxx.update (newrow"comment.text") with row"comment.text"
else
Console.WriteLine("At id {0}, comment ids do not match", i);
rowCount++;
catch
NB: I tried something like below it did not work
Over is [MY]SQL it works, e.g.
update longdescs set thetext='Test by GBR'  where comment_id=625;
HOWEVER for huge text strings, not sure how to handle ' inside the text
// this does not work though NO error is reported object[] rowdata = new object[4];
rowdata[0] = row.ItemArray[0];
rowdata[1] = row.ItemArray[1];
rowdata[2] = row.ItemArray[2];
rowdata[3] = (object)"Test of write"; // row.ItemArray[3];
resultsTableNew.Rows[rowCount].BeginEdit();
resultsTableNew.Rows[rowCount].ItemArray = rowdata;
resultsTableNew.Rows[rowCount].EndEdit();
resultsTableNew.Rows[rowCount].AcceptChanges();
resultsTableNew.AcceptChanges();
And another ps ; No ,matter what ways I use variables @oldtext :oldtext I cant get the var substitution to work  below.
Outcomes : No row updated, row updated showing nothing or "@oldtext"
Something like
"UPDATE longdescs SET thetext = 'my test' WHERE comment_id=123"
will work
string updateText = @"UPDATE longdescs SET thetext = @oldtext WHERE comment_id={0}";
_query2 = string.Format(updateText, row.ItemArray[1]);
// Set @newtext
Console.WriteLine("At id {0}={1}, comment id {2}, length differs {3} != {4}", i, row.ItemArray[0].ToString(), row.ItemArray[1].ToString(), row.ItemArray[2].ToString(), newrow.ItemArray[2].ToString());
if (i == 624)
OdbcCommand sqlComm = new OdbcCommand(_query2, _mySQLNew);
sqlComm.Parameters.AddWithValue("@oldtext", "Test by GBR");
int rowsaffected = sqlComm.ExecuteNonQuery();

Answer 1

Thanks for the reply. It is not possible to do a sample to show the issue because you need the bugzilla DB. Rather hope this issue rings a bell with someone.
Row state goes from "Modified" to "Unchanged" after the resultsTableNew.Rows[rowCount].AcceptChanges(); line. No errors.
Nb: I added "
Allow User Variables=True;" to the connection string.
I suspect the issue is related to MySQL quirk perhaps ?
I am using a 3.51 ODBC connector.
The direct SQL update "update longdescs set thetext='Test by GBR'  where comment_id=625;"
works. Trying to use a var on the right hand side does not.
I expanded the sqlComm object and can see the added parameter in it.
"UPDATE longdescs SET thetext = @oldtext WHERE comment_id=625";
Does not work, i.e. I can't get the var to be used. Text size is usually 1k but can get to 60k in a comment.
>> A manual alternative if someone can suggest how would be fine, as this is a one of fix to 6000 records.  i.e.
- clear comment field
- manually add 8K of info (whatever is the OK size) handling any " or ' in the data streams
- repeat addition of data until comment filled up
(context bugzilla)
               _mySQL =
newOdbcConnection(@"DRIVER={MySQL
ODBC 3.51 Driver}; SERVER=xxxxx; PORT=3306;
                DATABASE=bugs; USER=xxx; PASSWORD=xxx; Allow User Variables=True;
OPTION=0"
                _mySQL.Open();