private ASTNode createProjection()

in parser/sql/dialect/doris/src/main/java/org/apache/shardingsphere/sql/parser/doris/visitor/statement/DorisStatementVisitor.java [1783:1838]
55 lines of code
17 McCabe index (conditional complexity)

    private ASTNode createProjection(final ProjectionContext ctx, final AliasSegment alias, final ExpressionSegment projection) {
        if (projection instanceof AggregationProjectionSegment) {
            ((AggregationProjectionSegment) projection).setAlias(alias);
            return projection;
        }
        if (projection instanceof ExpressionProjectionSegment) {
            ((ExpressionProjectionSegment) projection).setAlias(alias);
            return projection;
        }
        if (projection instanceof FunctionSegment) {
            FunctionSegment functionSegment = (FunctionSegment) projection;
            ExpressionProjectionSegment result = new ExpressionProjectionSegment(functionSegment.getStartIndex(), functionSegment.getStopIndex(), functionSegment.getText(), functionSegment);
            result.setAlias(alias);
            return result;
        }
        if (projection instanceof CommonExpressionSegment) {
            CommonExpressionSegment segment = (CommonExpressionSegment) projection;
            ExpressionProjectionSegment result = new ExpressionProjectionSegment(segment.getStartIndex(), segment.getStopIndex(), segment.getText(), segment);
            result.setAlias(alias);
            return result;
        }
        // FIXME :For DISTINCT()
        if (projection instanceof ColumnSegment) {
            ExpressionProjectionSegment result = new ExpressionProjectionSegment(ctx.start.getStartIndex(), ctx.stop.getStopIndex(), getOriginalText(ctx), projection);
            result.setAlias(alias);
            return result;
        }
        if (projection instanceof SubqueryExpressionSegment) {
            SubqueryExpressionSegment subqueryExpressionSegment = (SubqueryExpressionSegment) projection;
            String text = ctx.start.getInputStream().getText(new Interval(subqueryExpressionSegment.getStartIndex(), subqueryExpressionSegment.getStopIndex()));
            SubqueryProjectionSegment result = new SubqueryProjectionSegment(subqueryExpressionSegment.getSubquery(), text);
            result.setAlias(alias);
            return result;
        }
        if (projection instanceof BinaryOperationExpression) {
            int startIndex = projection.getStartIndex();
            int stopIndex = null == alias ? projection.getStopIndex() : alias.getStopIndex();
            ExpressionProjectionSegment result = new ExpressionProjectionSegment(startIndex, stopIndex, projection.getText(), projection);
            result.setAlias(alias);
            return result;
        }
        if (projection instanceof ParameterMarkerExpressionSegment) {
            ParameterMarkerExpressionSegment result = (ParameterMarkerExpressionSegment) projection;
            result.setAlias(alias);
            return projection;
        }
        if (projection instanceof CaseWhenExpression || projection instanceof VariableSegment || projection instanceof BetweenExpression || projection instanceof InExpression
                || projection instanceof CollateExpression || projection instanceof NotExpression) {
            return createExpressionProjectionSegment(ctx, alias, projection);
        }
        ExpressionProjectionSegment result = null == alias
                ? new ExpressionProjectionSegment(projection.getStartIndex(), projection.getStopIndex(), String.valueOf(projection.getText()), projection)
                : new ExpressionProjectionSegment(projection.getStartIndex(), ctx.alias().stop.getStopIndex(), String.valueOf(projection.getText()), projection);
        result.setAlias(alias);
        return result;
    }