I've had a code similar to the following:
string sSql = String.Format("Column1 LIKE '%{0}%'", StringValue);
fareRows = dataset.Table.Select(sSql);
And DataTable.Select method returned me "Cannot perform 'Like' operation on System.Int64 and System.String".
System.Data.EvaluateException: Cannot perform 'Like' operation on System.Int64 and System.String.
at System.Data.BinaryNode.SetTypeMismatchError(Int32 op, Type left, Type right)
at System.Data.LikeNode.Eval(DataRow row, DataRowVersion version)
at System.Data.Select.AcceptRecord(Int32 record)
at System.Data.Select.GetLinearFilteredRows(Range range)
at System.Data.Select.SelectRows()
at System.Data.DataTable.Select(String filterExpression)
I've checked http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDataDataColumnClassExpressionTopic.asp and it didn't help.
After some debugging I recognized that I've used incorrect Column1 name and the column that I've used for filtering had integer type. So the error description is not obvious, but gives a mearningful hint.
I am not sure, that I should post this, but it could help people, who "Google first" instead of "think first"(like me in this case).
Update: I was surprised that there are guite a few hits to this post from Google searches for the error.
posted @ Sunday, July 15, 2007 11:39 AM