c# - Dapper 复杂映射 Dapper.Extensions Dapper.FluentMap

Question

我的代码有一点问题，并且要让dapper能够很好地使用它。

当我说我的代码是继承的，所以这不是我的设计。

我正在尝试替换 Entity Framework ，因为对数据库的调用效率较低，因此我希望更好地控制生成的 SQL，因此 Dapper 似乎是显而易见的选择。

我遇到的问题是我正在努力将我拥有的 poco 类映射到简洁的多查询。

我遇到的问题如下:

    public Feed GetFeedDapper(int feedId)
        {
            Feed feed = null;

            var sql =
            @"
            SELECT * FROM Feeds WHERE FeedId= @FeedId
            SELECT * FROM FeedFilterParameters WHERE FeedId = @FeedId
            SELECT * FROM TeamFeeds WHERE FeedId = @FeedId";

            using (var multi = DbConnection.QueryMultiple(sql, new { FeedId = feedId }))
            {
                feed = multi.Read<Feed>().Single();
                feed.Parameters = multi.Read<FeedFilterParameter>().ToList();
                feed.TeamFeeds = multi.Read<TeamFeed>().ToList();
            } 

            return feed;
        }

这让我从数据库中得到了正确的结果，这很好，问题是并非 Feed 对象上的所有属性都被映射。 Feed 有一个名为 InboundProperties 的属性，其类型为 InboundProperties，如下所示，在数据库中它们存储为 InboundProperties_{PropName}。这些属性没有被映射，我在 DapperExtensions 或 FluentMap 中尝试的任何方法都不起作用。

public class InboundProperties
{
    public string ExternalRef { get; set; }
    public string ExternalRefPrevious { get; set; }
    public string ExternalId { get; set; }
    public string ExternalName { get; set; }
    public string ExternalToken { get; set; }
    public int ExternalAPICounts { get; set; }
    public string ExternalLink { get; set; }
    public string ExternalPicture { get; set; }
    public string LastProcessedMessageId { get; set; }
    public long? LastProcessedMessageTime { get; set; }
    public DateTime? MessageCountStartDT { get; set; }
    public Int32 TenancyId { get; set; }
    public virtual int FeedScopeInt { get; set; }
}

任何人都可以帮我映射这些属性吗？

Answer 1

这就是我解决它的方法，但接受了 #rraszewski 答案，因为它也有效，但这只是意味着我需要以非常手动的方式处理所有选择。

public Feed GetFeedDapper(int feedId)
{
    Feed feed = null;

    var multiPredicate = new GetMultiplePredicate();
    multiPredicate.Add<Feed>(Predicates.Field<Feed>(x => x.FeedId, Operator.Eq, feedId));
    multiPredicate.Add<InboundProperties>(Predicates.Field<InboundProperties>(x => x.FeedId, Operator.Eq, feedId));
    multiPredicate.Add<OutboundProperties>(Predicates.Field<OutboundProperties>(x => x.FeedId, Operator.Eq, feedId));
    multiPredicate.Add<FeedFilterParameter>(Predicates.Field<FeedFilterParameter>(x => x.FeedId, Operator.Eq, feedId));
    multiPredicate.Add<TeamFeed>(Predicates.Field<TeamFeed>(x => x.FeedId, Operator.Eq, feedId));

    var result = DbConnection.GetMultiple(multiPredicate);

    feed = result.Read<Feed>().Single();
    feed.InboundProperties = result.Read<InboundProperties>().Single();
    feed.OutboundProperties = result.Read<OutboundProperties>().Single();
    feed.Parameters = result.Read<FeedFilterParameter>().ToList();
    feed.TeamFeeds = result.Read<TeamFeed>().ToList();

    return feed;
}

然后我映射类:

public class FeedMapper : ClassMapper<Feed>
{
    public FeedMapper()
    {
        base.Table("Feeds");
        Map(f => f.FeedId).Key(KeyType.Identity);

        Map(f => f.Owner).Ignore();
        Map(f => f.TeamFeeds).Ignore();
        Map(f => f.FeedDirection).Ignore();
        Map(f => f.InboundProperties).Ignore();
        Map(f => f.Parameters).Ignore();
        Map(f => f.OutboundProperties).Ignore();
        Map(f => f.RelatedTeams).Ignore();

        AutoMap();
    }
}

public class InboundPropertiesMapper : ClassMapper<InboundProperties>
{
    public InboundPropertiesMapper()
    {
        base.Table("Feeds");
        Map(f => f.FeedId).Key(KeyType.Identity);

        Map(f => f.Channel).Ignore();
        Map(f => f.FeedScope).Ignore();

        Map(f => f.ChannelInt).Column("InboundProperties_ChannelInt");
        Map(f => f.ExternalAPICounts).Column("InboundProperties_ExternalAPICounts");
        Map(f => f.ExternalId).Column("InboundProperties_ExternalId");
        Map(f => f.ExternalLink).Column("InboundProperties_ExternalLink");
        Map(f => f.ExternalName).Column("InboundProperties_ExternalName");
        Map(f => f.ExternalPicture).Column("InboundProperties_ExternalPicture");
        Map(f => f.ExternalRef).Column("InboundProperties_ExternalRef");
        Map(f => f.ExternalRefPrevious).Column("InboundProperties_ExternalRefPrevious");
        Map(f => f.ExternalToken).Column("InboundProperties_ExternalToken");
        Map(f => f.FeedScopeInt).Column("InboundProperties_FeedScopeInt");
        Map(f => f.LastProcessedMessageId).Column("InboundProperties_LastProcessedMessageId");
        Map(f => f.LastProcessedMessageTime).Column("InboundProperties_LastProcessedMessageTime");
        Map(f => f.MessageCountStartDT).Column("InboundProperties_MessageCountStartDT");
        Map(f => f.TenancyId).Column("InboundProperties_TenancyId");
        AutoMap();
    }
}

public class OutboundPropertiesMapper : ClassMapper<OutboundProperties>
{
    public OutboundPropertiesMapper()
    {
        base.Table("Feeds");
        Map(f => f.FeedId).Key(KeyType.Identity);

        Map(f => f.Channel).Ignore();
        Map(f => f.FeedType).Ignore();

        Map(f => f.OutboundFeedTypeInt).Column("OutboundProperties_OutboundFeedTypeInt");
        Map(f => f.TenancyId).Column("OutboundProperties_TenancyId");
        AutoMap();
    }
}