How to call Db view file in repository pattern? - asp.net

Question

I am creating a view file in SQL Server as shown in the image below.
and I created a model to get results from this view:
public class FactALLCousumption : BaseEntity, IAggregateRoot
{
public double sumActiveImportTotal { get; set; }
public DateTime hour { get; set; }
public int fullDateAlternateKey { get; set; }
}
But I can't call this view in my repository. My repository code is bellow:
public class FactCousumptionRepository: GenericRepository<FactCousumption>, IFactCousumptionRepository
{
public DbContext _dbContext;
public FactCousumptionRepository(BaseDbContext context) : base(context)
{
_dbContext = context;
}
public async Task<FactALLCousumption> GetTotalAllCousumption()
{
}
}

Answer 1

In EF Core 2.2 or 2.1, you could use Query types.
According to the screenshot and the model to be used for the View you provided , I make a simple working demo like below , you could refer to and make the modification as per your demand:
1.Model
public class FactCousumption
{
public int Id { get; set; }
public double SumActiveImportTotal { get; set; }
public int DateKeyId { get; set; }
[ForeignKey("DateKeyId")]
public Dim_Date Dim_Date { get; set; }
public int TimeAltKeyId { get; set; }
[ForeignKey("TimeAltKeyId")]
public Dim_Time Dim_Time { get; set; }
public int TariffKeyId { get; set; }
[ForeignKey("TariffKeyId")]
public Dim_Tariff Dim_Tariff { get; set; }
}
public class Dim_Date
{
[Key]
public int DateKey { get; set; }
public int FullDateAlternateKey { get; set; }
public DateTime Date { get; set; }
public ICollection<FactCousumption> FactCousumptions { get; set; }
}
public class Dim_Time
{
[Key]
public int TimeAltKey { get; set; }
public DateTime Hour { get; set; }
public ICollection<FactCousumption> FactCousumptions { get; set; }
}
public class Dim_Tariff
{
[Key]
public int TariffType { get; set; }
public string TariffName { get; set; }
public ICollection<FactCousumption> FactCousumptions { get; set; }
}
2.Create SQL View
CREATE VIEW [dbo].[View1]
AS SELECT SUM(FactCousumption.SumActiveImportTotal) AS consumption ,Dim_Time.HOUR,Dim_Date.FullDateAlternateKey,Dim_Tariff.TariffName
FROM FactCousumption INNER JOIN
Dim_Date ON FactCousumption.DateKeyId = Dim_Date.DateKey INNER JOIN
Dim_Time ON FactCousumption.TimeAltKeyId=Dim_Time.TimeAltKey INNER JOIN
Dim_Tariff ON FactCousumption.TariffKeyId=Dim_Tariff.TariffType
GROUP BY Dim_Date.FullDateAlternateKey, Dim_Time.HOUR ,Dim_Tariff.TariffName
3.The model that is used for the view , note : the property name in model should be consistent with those in the view
public class FactALLCousumption
{
public double consumption { get; set; }
public DateTime hour { get; set; }
public int fullDateAlternateKey { get; set; }
}
4.DbContext , create a DbQuery property in my DbContext to consume the view results inside the Model and set up the View especially if you have different view name than your Class.
public DbQuery<FactALLCousumption> FactALLCousumption { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Query<FactALLCousumption>().ToView("View1");
}
5.Finally you can easily get the results of the View like this.
public async Task<FactALLCousumption> GetTotalAllCousumption()
{
var result = await _context.FactALLCousumption.FirstOrDefaultAsync();
return result;
}
Note: It's worth noting that DbQuery won't be/is not supported anymore in EF Core 3.0. See here