Dapper嵌套对象查询 - 不填充所有属性

Question

我试图使用Dapper.NET将一个平面结果集返回到一个嵌套对象(EmergingIssue包含Reason和Status对象),但查询不会填充所有列.见下面的POCO:

public class EmergingIssue
{
    public string Category;
    public string Brand;
    public string Sku;
    public string SkuDesc;
    public string ManufacturingSite;
    public double? CurrentAvailableWfc;
    public Reason Reason;
    public Status Status;
    public double? TargetWfc;
    public DateTime? DateItemAdded;
    public string UserComment;
    public string PlannerID;
}

public class Reason
{
    public int ReasonId;
    public string ReasonDesc;
}

public class Status
{
    public int StatusId;
    public string StatusDesc;
}

下面是我试图将结果集投影到我的EmergingIssue类的代码(从类似的StackOverflow问题中采用):

public static List<EmergingIssue> GetEmergingIssues()
{
    using (var conn = new OracleConnection(Constant.DatabaseConnection()))
    {
        conn.Open();
        StringBuilder sql = new StringBuilder();

        sql.Append("SELECT ei.CATEGORY, ei.BRAND, ei.SKU, ei.SKU_DESC SkuDesc");
        sql.Append(" ,MANUFACTURING_SITE ManufacturingSite, CURRENT_AVAILABLE_WFC CurrentAvailableWfc");
        sql.Append(" ,ei.TARGET_WFC TargetWFC");
        sql.Append(" ,ei.DATE_ITEM_ADDED DateItemAdded");
        sql.Append(" ,ei.USER_COMMENT UserComment");
        sql.Append(" ,ei.PLANNER_ID PlannerID");
        sql.Append(" ,ei.REASON_ID ReasonID, r.REASON_DESC ReasonDesc");
        sql.Append(" ,ei.STATUS_ID StatusID, s.STATUS_DESC StatusDesc");
        sql.Append(" FROM EMERGING_ISSUE ei");
        sql.Append(" LEFT OUTER JOIN EMERGING_ISSUE_STATUS s ON s.STATUS_ID = ei.STATUS_ID");
        sql.Append(" LEFT OUTER JOIN MERGING_ISSUE_REASON r ON r.REASON_ID = ei.REASON_ID");

        List<EmergingIssue> emergingIssues = conn.Query<EmergingIssue, Reason, Status, EmergingIssue>(sql.ToString(),
            (ei, r, s) =>
            {
                ei.Reason = r;
                ei.Status = s;
                return ei;
            },
            splitOn: "ReasonID, StatusID").ToList();

        return emergingIssues;
    }
}

此结果返回多个字段,但未填充UserComment,PlannerID,DateItemAdded和其他几个字段.很明显,问题在于Linq函数正在投影数据,但我对语法不太熟悉,无法理解如何解决它.

此外,是否有一个有价值的Linq资源来学习更高级的功能？例如,我经常使用.Where(x => x.StringValue == "Test")(以及其他类似的,简单的)功能,但我不经常传递我正在尝试的功能.

Answer 1

问题出在这里:

splitOn: "ReasonID, StatusID"

你不能在splitOn字符串中添加任何空格,因为Dapper只是用逗号分割这个字符串 - 它会查找一个名为的列" StatusId"(在开头有一个空格)