//生成复合集合成员虚拟数据源连接。 private ISourceFragment GenerateVirtualCompositeJoinForCollectionMember(GenerateContext context, DbCollectionMemberExpression content, SelectFragment body, bool iscomposite) { var relation = CreateSource(context, content.RelationSet); body.AddSource(relation); relation.Join = EJoinType.InnerJoin; var pairs = iscomposite ? content.CompositePairs : content.Pairs; relation.Condition = pairs.Select(a => body.CreateExpression(a)).Merge(); return(relation); }