问题
For usage in my current project I've created a class that allows me to call SQL Server async.
My code looks like this:
internal class CommandAndCallback<TCallback, TError>
{
public SqlCommand Sql { get; set; }
public TCallback Callback { get; set; }
public TError Error { get; set; }
}
class MyCodes:SingletonBase<MyCodes>
{
private static string _connString = @"Data Source=MyDB;Initial Catalog=ED;Integrated Security=True;Asynchronous Processing=true;Connection Timeout=0;Application Name=TEST";
private MyCodes() { }
public void SetSystem(bool production)
{
_connString =
string.Format(@"Data Source=MyDB;Initial Catalog={0};Integrated Security=True;Asynchronous Processing=true;Connection Timeout=0;Application Name=TEST", production ? "ED" : "TEST_ED");
}
public void Add(string newCode, Action<int> callback, Action<string> error)
{
var conn = new SqlConnection(_connString);
SqlCommand cmd = conn.CreateCommand();
cmd.CommandTimeout = 0;
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = @"ADD_CODE";
cmd.Parameters.Add("@NEW", SqlDbType.NVarChar).Value = newCode;
cmd.Parameters.Add("@NewId", SqlDbType.Int).Direction = ParameterDirection.Output;
try
{
cmd.Connection.Open();
}
catch (Exception ex)
{
error(ex.ToString());
return;
}
var ar = new CommandAndCallback<Action<int>, Action<string>> { Callback = callback, Error = error, Sql = cmd };
cmd.BeginExecuteReader(Add_Handler, ar, CommandBehavior.CloseConnection);
}
private static void Add_Handler(IAsyncResult result)
{
var ar = (CommandAndCallback<Action<int>, Action<string>>)result.AsyncState;
if (result.IsCompleted)
{
try
{
ar.Sql.EndExecuteReader(result);
ar.Callback(Convert.ToInt32(ar.Sql.Parameters["@NewId"].Value));
}
catch (Exception ex)
{
ar.Error(ex.Message);
}
}
else
{
ar.Error("Error executing SQL");
}
}
public void Update(int codeId, string newCode, Action callback, Action<string> error)
{
var conn = new SqlConnection(_connString);
SqlCommand cmd = conn.CreateCommand();
cmd.CommandTimeout = 0;
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = @"UPDATE_CODE";
cmd.Parameters.Add("@CODE_ID", SqlDbType.Int).Value = codeId;
cmd.Parameters.Add("@NEW", SqlDbType.NVarChar).Value = newCode;
try
{
cmd.Connection.Open();
}
catch (Exception ex)
{
error(ex.ToString());
return;
}
var ar = new CommandAndCallback<Action, Action<string>> { Callback = callback, Error = error, Sql = cmd };
cmd.BeginExecuteReader(Update_Handler, ar, CommandBehavior.CloseConnection);
}
private static void Update_Handler(IAsyncResult result)
{
var ar = (CommandAndCallback<Action, Action<string>>)result.AsyncState;
if (result.IsCompleted)
{
try
{
ar.Sql.EndExecuteReader(result);
ar.Callback();
}
catch (Exception ex)
{
ar.Error(ex.Message);
}
}
else
{
ar.Error("Error executing SQL");
}
}
}
This may look like too much of code, but it lets me call it as so:
private void Add_Click(object sender, EventArgs e)
{
MyCodes.Instance.Add("Test",Success,Error)
}
private void Success(int newId)
{
MessageBox.Show(newId.ToString(), "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
private void Error(string error)
{
MessageBox.Show(error, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
Above code works just fine for me, I'm able to do every call async.
Problem that I have right now is to do multiple calls as transaction - I would like to update 2 codes and add one new.
Normally I would call update, then in success handler call second update, and in handler to second update I would call add that would return new id.
Something like:
-UPDATE CODE
|-UPDATE CODE
|-ADD CODE (only this one return something)
But I would like to call all of those as transaction, so if add code would break updates would rollback.
Question:
Is it possible to call multiple async queries as a transaction?
Can I call my above methods as transaction or do I must create separate method to call my procedures as one? (I would like to avoid this one because it's just copying the same code from one method to another)
I would like to add that I use .NET 3.5 so await and other nice features aren't an option.
回答1:
string cnnString =WebConfigurationManager.ConnectionStrings["MyString"].ConnectionString;
SqlConnection cnn = new SqlConnection(cnnString);
SqlTransaction transaction;
cnn.Open();
transaction = cnn.BeginTransaction();
try
{
// Command Objects for the transaction
SqlCommand cmd1 = new SqlCommand("sproc1", cnn);
SqlCommand cmd2 = new SqlCommand("sproc2", cnn);
cmd1.CommandType = CommandType.StoredProcedure;
cmd2.CommandType = CommandType.StoredProcedure;
cmd1.Parameters.Add(new SqlParameter("@Param1", SqlDbType.NVarChar, 50));
cmd1.Parameters["@Param1"].Value = paramValue1;
cmd1.Parameters.Add(new SqlParameter("@Param2", SqlDbType.NVarChar, 50));
cmd1.Parameters["@Param2"].Value = paramValue2;
cmd2.Parameters.Add(new SqlParameter("@Param3", SqlDbType.NVarChar, 50));
cmd2.Parameters["@Param3"].Value = paramValue3;
cmd2.Parameters.Add(new SqlParameter("@Param4", SqlDbType.NVarChar, 50));
cmd2.Parameters["@Param4"].Value = paramValue4;
cmd1.ExecuteNonQuery();
cmd2.ExecuteNonQuery();
transaction.Commit();
}
catch (SqlException sqlEx)
{
transaction.Rollback();
}
finally
{
cnn.Close();
cnn.Dispose();
}
回答2:
Yes, it is possible. Simply call SqlConnection.BeginTransaction before your first call, make you assign the returned SqlTransaction object to each SqlCommand.Transaction in the chain and call SqlTransaction.Commit() at the end.
回答3:
public class Command
{
public string sql { get; set; }
public CommandType cmdType { get; set; }
public Dictionary<string, object> parameter { get; set; } = null;
}
private Command insertInvoice(Invoice invoice)
{
try
{
Dictionary<string, object> parameterLocal = new Dictionary<string, object>();
parameterLocal.Add("p_customerId", invoice.customerId);
parameterLocal.Add("p_invoiceNo", invoice.invoiceNo);
parameterLocal.Add("p_invoiceDate", invoice.invoiceDate);
parameterLocal.Add("p_invoiceAmount", invoice.invoiceAmount);
parameterLocal.Add("p_withInvoice", invoice.withInvoice);
return (new Command { sql = "sp_insertInvoice", cmdType = CommandType.StoredProcedure, parameter = parameterLocal });
}
catch (Exception ex)
{
throw ex;
}
}
private Command insertInvoiceModel(InvoiceModel invoiceModel)
{
try
{
Dictionary<string, object> parameterLocal = new Dictionary<string, object>();
parameterLocal.Add("p_invoiceNo", invoiceModel.invoiceNo);
parameterLocal.Add("p_model", invoiceModel.model);
parameterLocal.Add("p_quantity", invoiceModel.quantity);
parameterLocal.Add("p_unitPrice", invoiceModel.unitPrice);
return (new Command { sql = "sp_insertInvoiceModel", cmdType = CommandType.StoredProcedure, parameter = parameterLocal });
}
catch (Exception ex)
{
throw ex;
}
}
List<Command> commandList = new List<Command>();
cmd = insertInvoice(invoicesave);
commandList.Add(cmd);
cmd = insertInvoiceModel(invoiceModelSave);
commandList.Add(cmd);
try
{
erplibmain.erpDac.runOleDbTransaction(commandList);
}
catch (Exception ex)
{
throw ex;
}
public void runOleDbTransaction(List<Command> commandList)
{
OleDbConnection erpConnection = new OleDbConnection(ErpDalMain.connectionstring);
erpConnection.Open();
OleDbCommand erpCommand = erpConnection.CreateCommand();
OleDbTransaction erpTrans;
// Start a local transaction
erpTrans = erpConnection.BeginTransaction();
// Assign transaction object for a pending local transaction
erpCommand.Connection = erpConnection;
erpCommand.Transaction = erpTrans;
try
{
foreach (Command cmd in commandList)
{
erpCommand.CommandText = cmd.sql;
erpCommand.CommandType = cmd.cmdType;
foreach (KeyValuePair<string, object> entry in cmd.parameter)
{
erpCommand.Parameters.AddWithValue(entry.Key, entry.Value);
}
erpCommand.ExecuteNonQuery();
erpCommand.Parameters.Clear();
}
erpTrans.Commit();
}
catch (Exception e)
{
try
{
erpTrans.Rollback();
}
catch (OleDbException ex)
{
if (erpTrans.Connection != null)
{
throw ex;
}
}
throw e;
}
finally
{
erpConnection.Close();
}
}
来源：https://stackoverflow.com/questions/15431285/call-multiple-sql-server-stored-procedures-in-a-transaction