Following numerous examples here and on MSDN, I can't figure out why I'm encountering an exception on adapter.Fill() below, nor do I understand why the exception is not caught here in the try{...} catch() clock, but rather in Program.Main().
The exception is
"- $exception {"Exception has been thrown by the target of an invocation."} System.Exception {System.Reflection.TargetInvocationException}
and the inner exception is
_message "ExecuteScalar: Connection property has not been initialized." string
What on earth am I missing here? Connection not initialized? I just opened it!
private static SqlCeConnection _cnxn = null;
public static SqlCeConnection cnxn
{
get
{
if (_cnxn == null)
{
_cnxn = new SqlCeConnection(global::Format_Generator_15.Properties.Settings.Default.FGConnectionString);
}
return _cnxn;
}
}
private static DataTable inputTable = null;
public static DataTable InputTable
{
get
{
if (inputTable == null)
{
if (cnxn.State == ConnectionState.Closed)
cnxn.Open();
try
{
SqlCeDataAdapter adapter = new SqlCeDataAdapter("select * from input", cnxn);
inputTable = new DataTable();
adapter.Fill(inputTable);
}
catch (Exception ex)
{
Console.WriteLine("Couldn't get the input table. " + ex.Message);
}
}
return inputTable;
}
}
Related
I send SQL command to ODBC to be able to insert into another application's database.
Looping in selected forms and its rows, I create command.
"OnTransactionCommand" simply returns an sql string of related row to be sent to ODBC for table 'STOCKTRN'
But the problem is that my integration function sometimes returns the error below:
ERROR [HY000] [TOD][ODBC][GENESIS]VISION: Cannot insert into 'STOCKTRN',No locks available
I am not sure but it is probably about the number of execution. With similar data when I test it with 15-20 records it works nicely. But Working with +50 records it returns error.
Is there any kind of limit or I am missing another part ?
My function:
private void MTransaction(MyGridView gvList)
{
try
{
var m_Integration = ctx.Integration.Take(1).FirstOrDefault();
if (m_Integration != null)
{
DbProviderFactory mFactory= DbProviderFactories.GetFactory(m_Integration.ServerType);
using (DbConnection dbcon = mFactory.CreateConnection())
{
dbcon.ConnectionString = m_Integration.ConnString;
for (int i = 0; i < gvList.RowCount; i++)
{
if (Convert.ToBoolean(gvList.GetRowCellValue(i, "Select")))
{
dbcon.Open();
int m_TransactionId = Convert.ToInt32(gvList.GetRowCellValue(i, "Id"));
MTransaction m_Transaction = ctx.Transaction.Where(c => c.Id == m_TransactionId).FirstOrDefault();
using (DbTransaction dbtr = dbcon.BeginTransaction())
{
try
{
using (DbCommand dbcmd = dbcon.CreateCommand())
{
dbcmd.Transaction = dbtr;
if (m_Transaction != null)
{
int TransactionRowCounter = 1;
foreach (var item in m_Transaction.TransactionRow)
{
dbcmd.CommandText = OnTransactionCommand(m_Transaction, item, TransactionRowCounter);
dbcmd.ExecuteNonQuery();
TransactionRowCounter++;
}
}
dbtr.Commit();
}
}
catch (Exception err)
{
dbtr.Rollback();
dbcon.Close();
XtraMessageBox.Show(err.Message);
continue;
}
}
dbcon.Close();
}
}
}
}
}
catch (Exception err)
{
SuccessMessage = "Error:\n" + err.Message;
}
}
I have done this manny times but now I get a error and I don't know how to fix it. The variables aren't null, they have value; I tried this in the DB and all is ok it return 1 row
List<Partido_E> lista = new List<Partido_E>();
try
{
conexion = bd.LeerDeBaseDeDatos();
orden = new OracleCommand(
#"select * from partido
where TO_CHAR(fecha, 'DD/MM/YYYY') = :anyo AND
equipo_l = :equipol AND
equipo_v = :equipov ", conexion);
orden.Parameters.Add(new OracleParameter("anyo", fecha));
orden.Parameters.Add(new OracleParameter("equipol", equipoL));
orden.Parameters.Add(new OracleParameter("equipov", equipoV));
orden.BindByName = true;
lector = orden.ExecuteReader();
while(lector.Read())
{
lista.Add(new Partido_E(lector.GetString(0),
lector.GetString(1),
lector.GetDateTime(2),
lector.GetString(3),
lector.GetString(4),
lector.IsDBNull(5) ? 0 : lector.GetInt32(5),
lector.IsDBNull(6) ? 0 : lector.GetInt32(6),
lector.IsDBNull(7) ? 0 : lector.GetInt32(7)
));
}
lector.Close();
lector.Dispose();
orden.Dispose();
bd.CerrarConexion();
}
catch (Exception e)
{
Console.WriteLine("Error " + e.ToString());
Console.ReadLine();
}
return lista;
Here is your problem - read comments
while (lector.Read())
{
// if you never come here, your reader is closed
}
lector.Close(); // <-- problem here
Oracle:
An OracleDataReader instance is constructed by a call to the ExecuteReader method of the OracleCommand object. The only properties that can be accessed after the DataReader is closed or has been disposed, are IsClosed and RecordsAffected.
This line lector.Read() can not throw null reference exception because line before that lector = orden.ExecuteReader(); will always return reader. If no rows, it will be closed.
Your code is not wormed well. should be
using (conn = new connection/getconnection)
{
using (cmd = new command)
{
using (reader = cmd.ExecuteReader)
{
} // no need to explicitly dispose/close here
}
}
I am throwing a new exception when a database row is not found.
Class that was called:
public ProfileBO retrieveProfileByCode(string profileCode)
{
return retrieveSingleProfile("profile_code", profileCode);
}
private ProfileBO retrieveSingleProfile(string termField, string termValue)
{
ProfileBO profile = new ProfileBO();
//Query string is temporary. Will make this a stored procedure.
string queryString = " SELECT * FROM GamePresenterDB.gp.Profile WHERE " + termField + " = '" + termValue + "'";
using (SqlConnection connection = new SqlConnection(App.getConnectionString()))
{
connection.Open();
SqlCommand command = new SqlCommand(queryString, connection);
SqlDataReader reader = command.ExecuteReader();
if (reader.Read())
{
profile = castDataReadertoProfileBO(reader, profile);
}
else
{
// No record was selected. log it and throw the exception (We'll log it later, for now just write to console.)
Console.WriteLine("No record was selected from the database for method retrieveSingleProfile()");
throw new InvalidOperationException("An exception occured. No data was found while trying to retrienve a single profile.");
}
reader.Close();
}
return profile;
}
However, when I catch the exception in the calling class, 'e' is now null. What am I doing wrong? I believe this works fine in Java, so C# must handle this differently.
Calling class:
private void loadActiveProfile()
{
try
{
ProfileBO profile = profileDAO.retrieveProfileByCode(p.activeProfileCode);
txtActiveProfileName.Text = profile.profile_name;
}
catch (InvalidOperationException e)
{
}
}
Now all the code has been put in the question, you can move the try catch outside of your 'loadActiveProfile' method and place it into 'retrieveSingleProfile'.
private void loadActiveProfile()
{
ProfileBO profile = profileDAO.retrieveProfileByCode(p.activeProfileCode);
txtActiveProfileName.Text = profile.profile_name;
}
removed the try catch^
private ProfileBO retrieveSingleProfile(string termField, string termValue)
{
try {
ProfileBO profile = new ProfileBO();
//Query string is temporary. Will make this a stored procedure.
string queryString = " SELECT * FROM GamePresenterDB.gp.Profile WHERE " + termField + " = '" + termValue + "'";
using (SqlConnection connection = new SqlConnection(App.getConnectionString()))
{
connection.Open();
SqlCommand command = new SqlCommand(queryString, connection);
SqlDataReader reader = command.ExecuteReader();
if (reader.Read())
{
profile = castDataReadertoProfileBO(reader, profile);
}
else
{
// No record was selected. log it and throw the exception (We'll log it later, for now just write to console.)
Console.WriteLine("No record was selected from the database for method retrieveSingleProfile()");
throw new InvalidOperationException("An exception occured. No data was found while trying to retrienve a single profile.");
}
reader.Close();
}
return profile;
}
catch(InvalidOperationException e)
{
}
}
Added try catch in the correct place.
You need to step into the catch block for e to be set to the thrown InvalidOperationException:
catch (System.InvalidOperationException e)
{
int breakPoint = 0; //<- set a breakpoint here.
//Either you reach the breakpoint and have an InvalidOperationException, or you don't reach the breakpoint.
MessageBox.Show(e.Message);
}
Also make sure that the InvalidOperationException you throw is actually a System.InvalidOperationException and not some custom type of yours called "InvalidOperationException".
Like #Clemens said, you need to show all the relevant code.
As a quick test, this works just fine:
class Program
{
static void Main(string[] args)
{
try
{
Console.WriteLine("Throwing error");
ThrowException();
}
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
Console.ReadKey(true);
}
static void ThrowException()
{
throw new InvalidOperationException("Blah blah blah");
}
}
I have an application that need to check to the database if a particular code exists; if it does exist, then have to load the corresponding value of that code else return null.
I don't want to hit the database for each code(running about 200.000 codes ).
so i got this small app to test the app.conf
public static void setAppSetting(string key, string value)
{
Configuration config = ConfigurationManager.OpenExeConfiguration(System.Reflection.Assembly.GetExecutingAssembly().Location);
if (config.AppSettings.Settings != null)
{
config.AppSettings.Settings.Remove(key);
}
config.AppSettings.Settings.Add(key, value);
config.Save(ConfigurationSaveMode.Modified);
}
public static string getAppSetting(string key)
{
try
{
Configuration config = ConfigurationManager.OpenExeConfiguration(System.Reflection.Assembly.GetExecutingAssembly().Location);
return config.AppSettings.Settings[key].ToString();
}
catch (Exception ex)
{
throw ex;
}
}
private static void loadKeysValues()
{
using (SqlConnection Gcon = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["constr"].ConnectionString))
{
//Open Connection
Gcon.Open();
using (SqlCommand sqlCmd = new SqlCommand("SELECT key,value FROM tables", Gcon))
{
using (SqlDataReader reader = sqlCmd.ExecuteReader())
{
if (reader.HasRows)
{
while (reader.Read())
{
System.Console.WriteLine(reader.GetString(0) + " , " + reader.GetString(1));
setAppSetting(reader.GetString(0), reader.GetString(1));
}
}
} // End of SqlDataReader
} // end of SqlCommand
}
}
static void Main(string[] args)
{
System.Console.WriteLine("Loading.........");
loadKeysValues();
System.Console.WriteLine("Completed");
System.Console.WriteLine("Input a key to get its value");
var input = System.Console.Read().ToString();
System.Console.WriteLine(getAppSetting(input));
System.Console.ReadLine();
}
But I got an error with the getAppSetting() at this line:
return config.AppSettings.Settings[key].ToString();
Error: Object reference not set to an instance of an object.
Plz help
Make sure that the value isn't null.
Try this:
if (config.AppSettings.Settings.ContainsKey(key) &&
config.AppSettings.Settings[key] != null)
{
return config.AppSettings.Settings[key].ToString();
}
Most likely you're trying to access a setting that doesn't exist. You could handle that exception in your catch block and return null in that case.
ToString() method don´t return the value, try with Value property:
return config.AppSettings.Settings[key].Value;
I am getting data from a mySql database and I am inserting it into another system. If a column has data in an incorrect format I log this and go to next row in the datatable. It works as expected but now if I have a search function in my method that gets some additional data and this function fails I want to immediately log this and go to next row. As it is now I just log it but it still gets inserted (without the value that didn't meet the search criteria).
My code:
private void updateCustomer()
{
MySqlConnection connection = new MySqlConnection("server=myServer;database=myDatabase;uid=myID;password=myPass");
MySqlCommand command = new MySqlCommand(#"mySelectCommand", connection);
DataTable customerTbl = new DataTable();
MySqlDataReader reader;
try
{
connection.Open();
reader = command.ExecuteReader();
if (reader.HasRows)
{
customerTbl.Load(reader);
}
reader.Close();
}
catch (Exception ex)
{
_out.error("Could not connect to mySql database");
}
finally
{
connection.Close();
}
foreach (DataRow row in customerTbl.Rows)
{
// Declare the customer variables
string customerID = Encoding.ASCII.GetString((byte[])row["Customer ID"]);
string ChildOf = row["Child of"].ToString();
// Create the customer object
Customer customer = new Customer();
customer.entityId = customerID;
if (ChildOf != "")
{
RecordRef parentRef = new RecordRef();
try
{
parentRef.internalId = searchCustomer(ChildOf);
}
catch
{
// If it fails here I want to log the customerID and then go to the next row in the datatable (could not find the internalid for ChildOf
_out.error(customerID + " was not updated. Error: invalid format Parent string");
}
finally
{
parentRef.typeSpecified = false;
customer.parent = parentRef;
}
}
// Invoke update() operation
WriteResponse response = _service.update(customer);
// Process the response
if (response.status.isSuccess)
{
}
else
{
_out.error(customerID + " was not updated. Error: " + getStatusDetails(response.status));
}
}
}
You need to remove the row in the catch block, and change the foreach loop to a backwards for loop to handle the removals.
I realized that I want to log the other failed fields as well. Maybe it's an inefficient way but I did something like:
bool findParent = true;
if (ChildOf != "")
{
try
{
RecordRef parentRef = new RecordRef();
parentRef.internalId = searchCustomer(ChildOf);
parentRef.typeSpecified = false;
customer.parent = parentRef;
}
catch
{
findParent = false;
_out.error(customerID + " was not inserted. Error: invalid format Parent string");
}
}
And then an if statement before trying to insert:
if (findPartner == true && findParent == true)
{
response = _service.add(customer);
// Process the response
if (response.status.isSuccess)
{
}
else
{
_out.error(customerID + " was not inserted. Error: " + getStatusDetails(response.status));
}
}
else
{
//_out.error(customerID + " was not updated. Error: " + getStatusDetails(response.status));
}
Use the row.HasError property.