visual c#.net & sql server 2000

sunspotzzz

hi, I am a student who is doing a project on small group sampling in my sch fyp project and i have encountered a major problem in my project that i need to solve quickly. I am using visual studio.net 2003 and sqlserver 2000. I am researching on small group sampling which require me to download the tpc.h benchmark that consist of several tables and one of them is a table that consist of 6 million records called "LINEITEM". the algo require me to query this table and count the column, "LineNumber", "Quantity" and "ExtendedPrice" and sort them by the distinct values in descending count order. I executed the query : SELECT L_ExtendedPrice, COUNT (*) AS Count FROM LINEITEM GROUP BY L_ExtendedPrice ORDER BY Count DESC in a sqlserver query analyzer and got 7, 50 and 90283 distinct values for the respective columns "LineNumber", "Quantity" and "ExtendedPrice". I wrote the same codes for all 3 in visual c#.net and was able to get what I want for "LineNumber" and "Quantity" but there is an error for the "ExtendedPrice" column. these are the codes that i have : _________________________________________________________________________________________________ string selectExtendedPriceOccurrences = "SELECT L_ExtendedPrice, COUNT (*) AS Count FROM LINEITEM GROUP BY L_ExtendedPrice ORDER BY Count DESC"; conn = new SqlConnection(source); conn.Open(); SqlDataAdapter daExtendedPriceOccurrences = new SqlDataAdapter (selectExtendedPriceOccurrences, conn); daExtendedPriceOccurrences.Fill(dsExtendedPriceOccurrences, "ExtendedPriceOccurrences"); conn.Close(); <-- ERROR ______________________________________________________________________________________________________ I have error at the following code : daExtendedPriceOccurrences.Fill(dsExtendedPriceOccurrences, "ExtendedPriceOccurrences"); conn.Close(); the above show the ERROR msg is : An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in system.data.dll Additional information: System error. can anyone please help. I am really in need of any advices provided.

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

sunspotzzz22y ago
Hi, thanks a lot for the exception string, I got this error msg when I execute the command: =========================================================== An unhandled exception of type 'System.FormatException' occurred in mscorlib.dll Additional information: Index (zero based) must be greater than or equal to zero and less than the size of the argument list. =========================================================== Do you have any idea what is wrong?
+1
miker22y ago
Sorry about that. Here is the correction: catch (SqlException e) { for (int i=0; i < e.Errors.Count; i++) { Console.WriteLine("Class: {1}", e.Errors[i].Class); Console.WriteLine("Error #{1}: {2} on line {3}.", e.Errors[i].Number, e.Errors[i].Message, e.Errors[i].LineNumber); Console.WriteLine("Error reported by {1} while connected to {2}", e.Errors[i].Source, e.Errors[i].Server); } }
+1
sunspotzzz22y ago
Hi, thank you for your reply. I pasted the above codes in a try..catch statement enclosing the DataAdapter. =========================================================== try { SqlDataAdapter daExtendedPriceOccurrences = new SqlDataAdapter (selectExtendedPriceOccurrences, conn); daExtendedPriceOccurrences.Fill(dsExtendedPrice, "ExtendedPriceOccurrences"); } catch (SqlException e) { for (int i=0; i < myErrors.Errors.Count; i++) { Console.WriteLine("Class: {1}", myErrors[i].Class); Console.WriteLine("Error #{1}: {2} on line {3}.", myErrors[i].Number, myErrors[i].Message, myErrors[i].LineNumber); Console.WriteLine("Error reported by {1} while connected to {2}", myErrors[i].Source, myErrors[i].Server); } } conn.Close(); } =========================================================== but when i compile i got the below message: =========================================================== The name 'myErrors' does not exist in the class or namespace 'ApproximateAggregateQuerying.AlgoForSmallGroupSampling.Algorithm' =========================================================== Can I know what am I supposed to do?
+1
miker22y ago
Do you have any error handling? Something like this may help you to see real error (from Visual Studio): catch (SqlException e) { for (int i=0; i < myErrors.Errors.Count; i++) { Console.WriteLine("Class: {1}", myErrors[i].Class); Console.WriteLine("Error #{1}: {2} on line {3}.", myErrors[i].Number, myErrors[i].Message, myErrors[i].LineNumber); Console.WriteLine("Error reported by {1} while connected to {2}", myErrors[i].Source, myErrors[i].Server); } }
+1