/// <summary>
/// Advances the data reader to the next result, when reading the results of batch SQL statements.
/// </summary>
/// <returns></returns>
public override bool NextResult()
{
if (!isOpen)
throw new MySqlException(ResourceStrings.NextResultIsClosed);
bool isCaching = command.CommandType == CommandType.TableDirect && command.EnableCaching &&
(commandBehavior & CommandBehavior.SequentialAccess) == 0;
// this will clear out any unread data
if (resultSet != null)
{
resultSet.Close();
if (isCaching)
TableCache.AddToCache(command.CommandText, resultSet);
}
// single result means we only return a single result set. If we have already
// returned one, then we return false
// TableDirect is basically a select * from a single table so it will generate
// a single result also
if (resultSet != null &&
((commandBehavior & CommandBehavior.SingleResult) != 0 || isCaching))
return false;
// next load up the next result set if any
try
{
do
{
resultSet = null;
// if we are table caching, then try to retrieve the resultSet from the cache
if (isCaching)
resultSet = TableCache.RetrieveFromCache(command.CommandText,
command.CacheAge);
if (resultSet == null)
{
resultSet = driver.NextResult(Statement.StatementId, false);
if (resultSet == null) return false;
resultSet.Cached = isCaching;
}
if (resultSet.Size == 0)
{
Command.lastInsertedId = resultSet.InsertedId;
if (affectedRows == -1)
affectedRows = resultSet.AffectedRows;
else
affectedRows += resultSet.AffectedRows;
}
} while (resultSet.Size == 0);
return true;
}
catch (MySqlException ex)
{
if (ex.IsFatal)
connection.Abort();
if (ex.Number == 0)
throw new MySqlException(ResourceStrings.FatalErrorReadingResult, ex);
if ((commandBehavior & CommandBehavior.CloseConnection) != 0)
Close();
throw;
}
}
private void ReportUsageAdvisorWarnings(int statementId, ResultSet rs)
{
if (!Settings.UseUsageAdvisor) return;
if (HasStatus(ServerStatusFlags.NoIndex))
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningNoIndex, driverId, UsageAdvisorWarningFlags.NoIndex);
else if (HasStatus(ServerStatusFlags.BadIndex))
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningBadIndex, driverId, UsageAdvisorWarningFlags.BadIndex);
// report abandoned rows
if (rs.SkippedRows > 0)
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningSkippedRows, driverId, UsageAdvisorWarningFlags.SkippedRows, rs.SkippedRows);
// report not all fields accessed
if (!AllFieldsAccessed(rs))
{
StringBuilder notAccessed = new StringBuilder("");
string delimiter = "";
for (int i = 0; i < rs.Size; i++)
if (!rs.FieldRead(i))
{
notAccessed.AppendFormat("{0}{1}", delimiter, rs.Fields[i].ColumnName);
delimiter = ",";
}
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningSkippedColumns, driverId, UsageAdvisorWarningFlags.SkippedColumns,
notAccessed.ToString());
}
// report type conversions if any
if (rs.Fields != null)
{
foreach (MySqlField f in rs.Fields)
{
StringBuilder s = new StringBuilder();
string delimiter = "";
foreach (Type t in f.TypeConversions)
{
s.AppendFormat("{0}{1}", delimiter, t.Name);
delimiter = ",";
}
if (s.Length > 0)
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningFieldConversion, driverId, UsageAdvisorWarningFlags.FieldConversion,
f.ColumnName, s.ToString());
}
}
}
private bool AllFieldsAccessed(ResultSet rs)
{
if (rs.Fields == null || rs.Fields.Length == 0) return true;
for (int i = 0; i < rs.Fields.Length; i++)
if (!rs.FieldRead(i)) return false;
return true;
}
public override ResultSet NextResult(int statementId, bool force)
{
// first let's see if we already have a resultset on this statementId
if (activeResult != null)
{
//oldRS = activeResults[statementId];
if (Settings.UseUsageAdvisor)
ReportUsageAdvisorWarnings(statementId, activeResult);
MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.ResultClosed,
Resources.TraceResultClosed, driverId, activeResult.TotalRows, activeResult.SkippedRows,
rowSizeInBytes);
rowSizeInBytes = 0;
activeResult = null;
}
activeResult = base.NextResult(statementId, force);
return activeResult;
}
private void ReportUsageAdvisorWarnings(int statementId, ResultSet rs)
{
if (!Settings.UseUsageAdvisor)
{
return;
}
if (HasStatus(ServerStatusFlags.NoIndex))
{
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningNoIndex, driverId, UsageAdvisorWarningFlags.NoIndex);
}
else if (HasStatus(ServerStatusFlags.BadIndex))
{
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningBadIndex, driverId, UsageAdvisorWarningFlags.BadIndex);
}
// report abandoned rows
if (rs.SkippedRows > 0)
{
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningSkippedRows, driverId, UsageAdvisorWarningFlags.SkippedRows, rs.SkippedRows);
}
// report not all fields accessed
if (!AllFieldsAccessed(rs))
{
StringBuilder notAccessed = new StringBuilder("");
string delimiter = "";
for (int i = 0; i < rs.Size; i++)
{
if (!rs.FieldRead(i))
{
notAccessed.AppendFormat("{0}{1}", delimiter, rs.Fields[i].ColumnName);
delimiter = ",";
}
}
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningSkippedColumns, driverId, UsageAdvisorWarningFlags.SkippedColumns,
notAccessed.ToString());
}
// report type conversions if any
if (rs.Fields != null)
{
foreach (MySqlField f in rs.Fields)
{
StringBuilder s = new StringBuilder();
string delimiter = "";
foreach (Type t in f.TypeConversions)
{
s.AppendFormat("{0}{1}", delimiter, t.Name);
delimiter = ",";
}
if (s.Length > 0)
{
MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
Resources.TraceUAWarningFieldConversion, driverId, UsageAdvisorWarningFlags.FieldConversion,
f.ColumnName, s.ToString());
}
}
}
}
public static void AddToCache(string commandText, ResultSet resultSet)
{
cache.AddToCache(commandText, resultSet);
}
