如何从 dapper repo 调用返回具有字典属性的对象

Question

我有一个包含以下内容的对象发票：

public class Invoice
{
    public int InvoiceId { get; set; }
    
    public int GroupId { get; set; }
    
    public IDictionary<int, double> Variables { get; set; }
}

然后我有一个简洁的存储库查询，如下所示：

const string query = @"select InvoiceId, GroupId, VariableId, VariableValue
                       From Invoices;";


var result = ExecuteQuery<Invoice>(query, null);

我想要得到的是上面的查询将返回一个平面数据集，我想在其中按 InvoiceId、GroupId 分组，然后将所有 VariableId、VariableValues 放入字典中。

如何使用 LINQ select many ToDictionary 来实现这一点？

谢谢！

Answer 1

var invoiceDictionary = new Dictionary<int, Invoice>(); 

var list = connection.Query<Invoice, IDictionary<int, double>, Invoice>(
        sql,
        (invoice, variables) =>
        {
            Invoice invoiceEntry;

            if (!invoiceDictionary.TryGetValue(invoice.InvoiceID, out invoiceEntry))
            {
                invoiceEntry = invoice;
                invoiceEntry.Variables = new Dictionary<int, double>();
                invoiceDictionary.Add(invoiceEntry.InvoiceID, invoiceEntry);
            }

            invoiceEntry.Variables.Add(variables.Key, variables.Value);
            return invoiceEntry;
        },
        splitOn: "VariablesId")
    .Distinct()
    .ToList();