private AggregationDistinctToken GenerateSQLToken(AggregationDistinctProjection projection)
{
ShardingAssert.ShouldBeNotNull(projection.GetAlias(), "alias is required");
String derivedAlias = DerivedColumn.IsDerivedColumnName(projection.GetAlias()) ? projection.GetAlias() : null;
return(new AggregationDistinctToken(projection.StartIndex, projection.StopIndex, projection.GetDistinctInnerExpression(), derivedAlias));
}
private AggregationDistinctProjection CreateProjection(string sql, AggregationDistinctProjectionSegment projectionSegment)
{
var innerExpression = sql.SubStringWithEndIndex(projectionSegment.GetInnerExpressionStartIndex(), projectionSegment.GetStopIndex() + 1);
var alias = projectionSegment.GetAlias() ?? DerivedColumn.Get(DerivedColumnEnum.AGGREGATION_DISTINCT_DERIVED).GetDerivedColumnAlias(aggregationDistinctDerivedColumnCount++);
AggregationDistinctProjection result = new AggregationDistinctProjection(
projectionSegment.GetStartIndex(), projectionSegment.GetStopIndex(), projectionSegment.GetAggregationType(), innerExpression, alias, projectionSegment.GetDistinctExpression());
if (AggregationTypeEnum.AVG == result.GetAggregationType())
{
AppendAverageDistinctDerivedProjection(result);
}
return(result);
}
private void AppendAverageDistinctDerivedProjection(AggregationDistinctProjection averageDistinctProjection)
{
var innerExpression = averageDistinctProjection.GetInnerExpression();
var distinctInnerExpression = averageDistinctProjection.GetDistinctInnerExpression();
var countAlias = DerivedColumn.Get(DerivedColumnEnum.AVG_COUNT_ALIAS).GetDerivedColumnAlias(aggregationAverageDerivedColumnCount);
AggregationDistinctProjection countDistinctProjection = new AggregationDistinctProjection(0, 0, AggregationTypeEnum.COUNT, innerExpression, countAlias, distinctInnerExpression);
var sumAlias = DerivedColumn.Get(DerivedColumnEnum.AVG_SUM_ALIAS).GetDerivedColumnAlias(aggregationAverageDerivedColumnCount);
AggregationDistinctProjection sumDistinctProjection = new AggregationDistinctProjection(0, 0, AggregationTypeEnum.SUM, innerExpression, sumAlias, distinctInnerExpression);
averageDistinctProjection.GetDerivedAggregationProjections().Add(countDistinctProjection);
averageDistinctProjection.GetDerivedAggregationProjections().Add(sumDistinctProjection);
aggregationAverageDerivedColumnCount++;
}
