public override IASTNode VisitAggregationFunction(MySqlCommandParser.AggregationFunctionContext ctx)
{
String aggregationType = ctx.aggregationFunctionName().GetText();
return(AggregationType.IsAggregationType(aggregationType)
? CreateAggregationSegment(ctx, aggregationType) : new ExpressionProjectionSegment(ctx.Start.StartIndex, ctx.Stop.StopIndex, ctx.GetText()));
}
private String getDistinctExpression(MySqlCommandParser.AggregationFunctionContext ctx)
{
StringBuilder result = new StringBuilder();
for (int i = 3; i < ctx.ChildCount - 1; i++)
{
result.Append(ctx.GetChild(i).GetText());
}
return(result.ToString());
}
private IASTNode CreateAggregationSegment(MySqlCommandParser.AggregationFunctionContext ctx, String aggregationType)
{
AggregationTypeEnum type = AggregationType.ValueOf(aggregationType.ToUpper());
int innerExpressionStartIndex = ((ITerminalNode)ctx.GetChild(1)).Symbol.StartIndex;
if (null == ctx.distinct())
{
return(new AggregationProjectionSegment(ctx.Start.StartIndex, ctx.Stop.StopIndex, type, innerExpressionStartIndex));
}
return(new AggregationDistinctProjectionSegment(ctx.Start.StartIndex, ctx.Stop.StopIndex, type, innerExpressionStartIndex, getDistinctExpression(ctx)));
}
