ASP.NET Sql einfügen Fehlerdatentyp nvarchar in numerischer

Question

Entity-Klasse umzuwandeln, die das Objekt I DB hinzufügen mag:

public class Item 
{ 
    [Key] 
    public long Id { get; set; } 

    [MaxLength(100)] 
    [Required] 
    public string Name { get; set; } 

    [MaxLength(1000)] 
    public string Description { get; set; } 

    [Required] 
    public decimal Price { get; set; } 

    public Currency Currency { get; set; } 

    public bool Negotiable { get; set; } 

    public virtual List<Photo> Photos { get; set; } 
    public Category Category { get; set; } 

    [Required] 
    public byte CategoryId { get; set; } 

    [Required] 
    public string OwnerId { get; set; } 

    public ApplicationUser Owner { get; set; } 
} 

Es ist lokaler Db, mit Code-First-Ansatz erzeugt. Und nun möchte ich eine Zeile in meiner Anwendung hinzufügen mit SQL-Befehl:

public void AddItem(Item item) 
    { 

     var cnnString = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString; 

     var cmd = "INSERT INTO Items([Id],[Name],[Description] ,[Price] , [Currency] , [Negotiable], [CategoryId], [OwnerId]) VALUES(@id,@name,@description,@price,@currency,@negotiable,@categoryId,@ownerId)"; 

     using (SqlConnection cnn = new SqlConnection(cnnString)) 
     { 

      using (SqlCommand cmd1 = new SqlCommand(cmd, cnn)) 
      { 
       cnn.Open(); 
       cmd1.CommandText = "SELECT MAX(Id) FROM Items"; 
       using (SqlDataReader reader = cmd1.ExecuteReader()) 
       { 
        while (reader.Read()) 
        { 
         int maxId = Convert.ToInt32(cmd1.ExecuteScalar()); 
         item.Id = maxId; 
        } 
       } 

       cmd1.Parameters.AddWithValue("@id", item.Id); 
       cmd1.Parameters.AddWithValue("@name", item.Name); 
       cmd1.Parameters.AddWithValue("@description", item.Description); 
       cmd1.Parameters.Add("@price", SqlDbType.Decimal).Value = item.Price; 
       cmd1.Parameters.AddWithValue("@currency", item.Currency); 
       cmd1.Parameters.AddWithValue("@negotiable", item.Negotiable); 
       cmd1.Parameters.AddWithValue("@categoryId", item.CategoryId); 
       cmd1.Parameters.AddWithValue("@ownerId", item.OwnerId); 



       cmd1.ExecuteNonQuery(); //* 
      } 
     } 

    } 

EDITED: Dieser Code oben wirft Ausnahme: hier ist bereits eine offene Datareader mit diesem Befehl zugeordnet, der zuerst geschlossen werden muss „“.

DB Schema in T-SQL wie unten definiert ist:

CREATE TABLE [dbo].[Items] (
[Id]   BIGINT   IDENTITY (1, 1) NOT NULL, 
[Name]  NVARCHAR (100) NOT NULL, 
[Description] NVARCHAR (1000) NULL, 
[Price]  DECIMAL (18, 2) NOT NULL, 
[Currency] INT    NOT NULL, 
[Negotiable] BIT    NOT NULL, 
[CategoryId] TINYINT   NOT NULL, 
[Category_Id] INT    NULL, 
[OwnerId]  NVARCHAR (128) DEFAULT ('') NOT NULL, 
CONSTRAINT [PK_dbo.Items] PRIMARY KEY CLUSTERED ([Id] ASC), 
CONSTRAINT [FK_dbo.Items_dbo.Categories_Category_Id] FOREIGN KEY ([Category_Id]) REFERENCES [dbo].[Categories] ([Id]), 
CONSTRAINT [FK_dbo.Items_dbo.AspNetUsers_OwnerId] FOREIGN KEY ([OwnerId]) REFERENCES [dbo].[AspNetUsers] ([Id]) ON DELETE CASCADE 

);

Answer 1

ändern Sie die Abfrage zu diesem einfügen. und versuchen jetzt

  public long AddItem(Item item) 
     { 

     var cnnString = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString; 
     var cmdInsert = "INSERT INTO Items([Name],[Description] ,[Price] , [Currency] , [Negotiable], [CategoryId], [OwnerId]) VALUES(@name,@description,@price,@currency,@negotiable,@categoryId,@ownerId)"; 


     using (SqlConnection cnn = new SqlConnection(cnnString)) 
     { 
     cnn.Open(); 
     using (SqlCommand cmd1 = new SqlCommand(cmdInsert, cnn)) 
     { 

     cmd1.Parameters.AddWithValue("@name", item.Name); 
     cmd1.Parameters.AddWithValue("@description", item.Description); 
     cmd1.Parameters.Add("@price", SqlDbType.Decimal).Value = item.Price; 
     cmd1.Parameters.AddWithValue("@currency", item.Currency); 
     cmd1.Parameters.AddWithValue("@negotiable", item.Negotiable); 
     cmd1.Parameters.AddWithValue("@categoryId", item.CategoryId); 
     cmd1.Parameters.AddWithValue("@ownerId", item.OwnerId); 

     cmd1.ExecuteNonQuery(); 
     } 
     cnn.Close(); 
     } 

     } 

Answer 2

Lassen Sie uns an Ihren Code aussehen:

var cmd = "INSERT INTO Items VALUES(@id, 
@name, 
@description, 
@price, 
@currency,  
@negotiable,  
@categoryId,  
@ownerId)"; 

und Tabellendefinition:

CREATE TABLE [dbo].[Items] (
[Id]   BIGINT   IDENTITY (1, 1) NOT NULL, 
[Name]  NVARCHAR (100) NOT NULL, 
[Description] NVARCHAR (1000) NULL, 
[Price]  DECIMAL (18, 2) NOT NULL, 
[Currency] INT    NOT NULL, 
[Negotiable] BIT    NOT NULL, 
[CategoryId] TINYINT   NOT NULL, 
[Category_Id] INT    NULL, 
[OwnerId]  NVARCHAR (128) DEFAULT ('') NOT NULL, 
CONSTRAINT [PK_dbo.Items] PRIMARY KEY CLUSTERED ([Id] ASC), 
CONSTRAINT [FK_dbo.Items_dbo.Categories_Category_Id] FOREIGN KEY ([Category_Id]) REFERENCES [dbo].[Categories] ([Id]), 
CONSTRAINT [FK_dbo.Items_dbo.AspNetUsers_OwnerId] FOREIGN KEY ([OwnerId]) REFERENCES [dbo].[AspNetUsers] ([Id]) ON DELETE CASCADE) 

Sie haben CategoryId, category_id, ownerID in Tabellendefinition und nur @categoryId, @ ownerId in C#. Sie haben @category_Id Wert vergessen, ich denke