private void ExecuteDeleteStatement(RequestExecutionContext context, RequestExecutionBuffer buffer, IDriverDataEnumerator sourceEnumerator)
{
if (sourceEnumerator == null)
{
return;
}
buffer.RowsOutput = 0;
var cts = context.CancellationTokenSource;
context.ClauseEvaluationContext.RowNumber = 0;
context.ClauseEvaluationContext.RowNumberInOutput = context.ClauseEvaluationContext.RowNumber;
var changeBuffer = context.ClauseEvaluationContext.ChangeBuffer;
var changeset = m_storageDriver.CreateChangeset(changeBuffer, context.ParsedRequest.IsBulk);
try
{
changeBuffer.ChangeType = DriverChangeType.Delete;
while (!cts.IsCancellationRequested && sourceEnumerator.MoveNext())
{
// if record satisfies WHERE criteria, compute updated values and give them to driver
if (ApplyWhereClause(context))
{
// load internal ID, it is needed
sourceEnumerator.FetchAdditionalFields();
sourceEnumerator.FetchInternalEntityIdIntoChangeBuffer(changeBuffer, context);
m_storageDriver.AddChange(changeset);
}
// row number is needed for "rownum()" Pql function
context.ClauseEvaluationContext.RowNumber++;
// output row number is needed for "rownumoutput()" Pql function
context.ClauseEvaluationContext.RowNumberInOutput = context.ClauseEvaluationContext.RowNumber;
}
if (!cts.IsCancellationRequested)
{
context.RecordsAffected = m_storageDriver.Apply(changeset);
}
}
catch
{
m_storageDriver.Discard(changeset);
throw;
}
}