コード例 #1
0
 protected override Expression VisitJoin(JoinExpression join)
 {
     if (join.Join == JoinType.SingletonLeftOuter)
     {
         // first visit right side w/o looking at condition
         Expression        right = this.Visit(join.Right);
         AliasedExpression ax    = right as AliasedExpression;
         if (ax != null && !this.allColumnsUsed.ContainsKey(ax.Alias))
         {
             // if nothing references the alias on the right, then the join is redundant
             return(this.Visit(join.Left));
         }
         // otherwise do it the right way
         Expression cond = this.Visit(join.Condition);
         Expression left = this.Visit(join.Left);
         right = this.Visit(join.Right);
         return(this.UpdateJoin(join, join.Join, left, right, cond));
     }
     else
     {
         // visit join in reverse order
         Expression condition = this.Visit(join.Condition);
         Expression right     = this.VisitSource(join.Right);
         Expression left      = this.VisitSource(join.Left);
         return(this.UpdateJoin(join, join.Join, left, right, condition));
     }
 }
コード例 #2
0
        protected override Expression VisitJoin(JoinExpression join)
        {
            Expression result = base.VisitJoin(join);

            join = result as JoinExpression;
            if (join != null)
            {
                AliasedExpression right = join.Right as AliasedExpression;
                if (right != null)
                {
                    AliasedExpression similarRight = (AliasedExpression)this.FindSimilarRight(join.Left as JoinExpression, join);
                    if (similarRight != null)
                    {
                        this.map.Add(right.Alias, similarRight.Alias);
                        return(join.Left);
                    }
                }
            }
            return(result);
        }