/// <include file='docs/mysqlcommand.xml' path='docs/ExecuteReader1/*'/>
private void InnerBeginExecuteReader(CommandBehavior behavior)
{
lastInsertedId = -1;
CheckState();
if (cmdText == null ||
cmdText.Trim().Length == 0)
throw new InvalidOperationException(Resources.CommandTextNotInitialized);
string sql = TrimSemicolons(cmdText);
// now we check to see if we are executing a query that is buggy
// in 4.1
connection.IsExecutingBuggyQuery = false;
if (!connection.driver.Version.isAtLeast(5, 0, 0) &&
connection.driver.Version.isAtLeast(4, 1, 0))
{
string snippet = sql;
if (snippet.Length > 17)
snippet = sql.Substring(0, 17);
snippet = snippet.ToLower(CultureInfo.InvariantCulture);
connection.IsExecutingBuggyQuery =
snippet.StartsWith("describe") ||
snippet.StartsWith("show table status");
}
if (statement == null || !statement.IsPrepared)
{
if (CommandType == CommandType.StoredProcedure)
statement = new StoredProcedure(this, sql);
else
statement = new PreparableStatement(this, sql);
}
// stored procs are the only statement type that need do anything during resolve
statement.Resolve();
// Now that we have completed our resolve step, we can handle our
// command behaviors
HandleCommandBehaviors(behavior);
updatedRowCount = -1;
try
{
MySqlDataReader reader = new MySqlDataReader(this, statement, behavior);
// start a threading timer on our command timeout
timedOut = false;
canceled = false;
// execute the statement
statement.Execute();
// start a timeout timer
if (connection.driver.Version.isAtLeast(5, 0, 0) &&commandTimeout > 0)
{
ExecuteQueryManager.Instace.Add(this);
}
reader.BeginNextResult();
MysqlAsyncResult result = _asyncResult as MysqlAsyncResult;
result.DataReader = reader;
}
catch (MySqlException ex)
{
if (ex.IsFatal)
Connection.Close();
if (ex.Number == 0)
throw new MySqlException(Resources.FatalErrorDuringExecute, ex);
throw;
}
}
/// <include file='docs/mysqlcommand.xml' path='docs/ExecuteReader1/*'/>
private void InnerBeginExecuteReader(CommandBehavior behavior)
{
CheckState();
Driver driver = connection.driver;
lock (driver)
{
// We have to recheck that there is no reader, after we got the lock
if (connection.Reader != null)
{
throw new MySqlException(Resources.DataReaderOpen);
}
#if !CF
System.Transactions.Transaction curTrans = System.Transactions.Transaction.Current;
if (curTrans != null)
{
bool inRollback = false;
if (driver.CurrentTransaction != null)
inRollback = driver.CurrentTransaction.InRollback;
if (!inRollback)
{
TransactionStatus status = TransactionStatus.InDoubt;
try
{
// in some cases (during state transitions) this throws
// an exception. Ignore exceptions, we're only interested
// whether transaction was aborted or not.
status = curTrans.TransactionInformation.Status;
}
catch (TransactionException)
{
}
if (status == TransactionStatus.Aborted)
throw new TransactionAbortedException();
}
}
#endif
commandTimer = new CommandTimer(connection, CommandTimeout);
lastInsertedId = -1;
cmdText = cmdText.Trim();
if (String.IsNullOrEmpty(cmdText))
throw new InvalidOperationException(Resources.CommandTextNotInitialized);
string sql = cmdText.Trim(';');
if (CommandType == CommandType.TableDirect)
sql = "SELECT * FROM " + sql;
if (statement == null || !statement.IsPrepared)
{
if (CommandType == CommandType.StoredProcedure)
statement = new StoredProcedure(this, sql);
else
statement = new PreparableStatement(this, sql);
}
// stored procs are the only statement type that need do anything during resolve
statement.Resolve(false);
// Now that we have completed our resolve step, we can handle our
// command behaviors
HandleCommandBehaviors(behavior);
updatedRowCount = -1;
try
{
MySqlDataReader reader = new MySqlDataReader(this, statement, behavior);
connection.Reader = reader;
canceled = false;
// execute the statement
statement.Execute();
// wait for data to return
reader.BeginNextResult();
MysqlAsyncResult result = _asyncResult as MysqlAsyncResult;
result.DataReader = reader;
}
catch (TimeoutException tex)
{
connection.HandleTimeoutOrThreadAbort(tex);
throw; //unreached
}
catch (ThreadAbortException taex)
{
connection.HandleTimeoutOrThreadAbort(taex);
throw;
}
catch (IOException ioex)
{
connection.Abort(); // Closes connection without returning it to the pool
throw new MySqlException(Resources.FatalErrorDuringExecute, ioex);
}
catch (MySqlException ex)
{
if (ex.InnerException is TimeoutException)
throw; // already handled
try
{
ResetReader();
ResetSqlSelectLimit();
}
catch (Exception)
{
// Reset SqlLimit did not work, connection is hosed.
Connection.Abort();
throw new MySqlException(ex.Message, true, ex);
}
// if we caught an exception because of a cancel, then just return null
//只有主动调用Cancel时才会出现这个异常，注释让他throw吧
//if (ex.IsQueryAborted)
// return null;
if (ex.IsFatal)
Connection.Close();
if (ex.Number == 0)
throw new MySqlException(Resources.FatalErrorDuringExecute, ex);
throw;
}
finally
{
if (connection != null)
{
if (connection.Reader == null)
{
// Something went seriously wrong, and reader would not
// be able to clear timeout on closing.
// So we clear timeout here.
ClearCommandTimer();
}
}
}
}
}