private IASTNode CreateProjection(MySqlCommandParser.ProjectionContext ctx, AliasSegment alias)
{
IASTNode projection = Visit(ctx.expr());
if (projection is AggregationProjectionSegment aggregationProjectionSegment)
{
aggregationProjectionSegment.SetAlias(alias);
return(projection);
}
if (projection is ExpressionProjectionSegment expressionProjection)
{
expressionProjection.SetAlias(alias);
return(projection);
}
if (projection is CommonExpressionSegment commonExpressionSegment)
{
ExpressionProjectionSegment r = new ExpressionProjectionSegment(commonExpressionSegment.GetStartIndex(), commonExpressionSegment.GetStopIndex(), commonExpressionSegment.GetText());
r.SetAlias(alias);
return(r);
}
// FIXME :For DISTINCT()
if (projection is ColumnSegment)
{
ExpressionProjectionSegment r = new ExpressionProjectionSegment(ctx.Start.StartIndex, ctx.Stop.StopIndex, ctx.GetText());
r.SetAlias(alias);
return(r);
}
if (projection is SubQueryExpressionSegment subQueryExpressionSegment)
{
SubQueryProjectionSegment r = new SubQueryProjectionSegment(subQueryExpressionSegment.SubQuery);
r.SetAlias(alias);
return(r);
}
LiteralExpressionSegment column = (LiteralExpressionSegment)projection;
ExpressionProjectionSegment result = null == alias ? new ExpressionProjectionSegment(column.GetStartIndex(), column.GetStopIndex(), $"{column.GetLiterals()}")
: new ExpressionProjectionSegment(column.GetStartIndex(), ctx.alias().Stop.StopIndex, $"{column.GetLiterals()}");
result.SetAlias(alias);
return(result);
}
public override IASTNode VisitProjection(MySqlCommandParser.ProjectionContext ctx)
{
// FIXME :The stop index of project is the stop index of projection, instead of alias.
if (null != ctx.qualifiedShorthand())
{
MySqlCommandParser.QualifiedShorthandContext shorthand = ctx.qualifiedShorthand();
ShorthandProjectionSegment result = new ShorthandProjectionSegment(shorthand.Start.StartIndex, shorthand.Stop.StopIndex);
IdentifierValue identifier = new IdentifierValue(shorthand.identifier().GetText());
result.SetOwner(new OwnerSegment(shorthand.identifier().Start.StartIndex, shorthand.identifier().Stop.StopIndex, identifier));
return(result);
}
AliasSegment alias = null == ctx.alias() ? null : (AliasSegment)Visit(ctx.alias());
if (null != ctx.columnName())
{
ColumnSegment column = (ColumnSegment)Visit(ctx.columnName());
ColumnProjectionSegment result = new ColumnProjectionSegment(column);
result.SetAlias(alias);
return(result);
}
return(CreateProjection(ctx, alias));
}
