使用 Angularjs 通过 REST API 向数据库添加新记录

Question

I'm trying to add a new record to the database using REST API. The DELETE and GET methods work just fine, but I can't figure out what's wrong with the POST method.

My API Controller:

[HttpPost]      // POST: api/Contacts    //to add image as param?
public void InsertNewContact([FromBody]Contact Contact)
{
    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["MyConStr"].ConnectionString);
    SqlCommand cmd = new SqlCommand(@"INSERT INTO Contacts(Name,Phone,Mail,City,Address) VALUES(@Name, @Phone,@Mail,@City,@Address)", con);
    SqlParameter Name = new SqlParameter("@Name", Contact.Name);
    cmd.Parameters.Add(Name);
    SqlParameter Phone = new SqlParameter("@Phone", Contact.Phone);
    cmd.Parameters.Add(Phone);
    SqlParameter Mail = new SqlParameter("@Mail", Contact.Mail);
    cmd.Parameters.Add(Mail);
    SqlParameter City = new SqlParameter("@City", Contact.City);
    cmd.Parameters.Add(City);
    SqlParameter Address = new SqlParameter("@Address", Contact.Address);
    cmd.Parameters.Add(Address);

    try
    {
        con.Open();
        cmd.ExecuteNonQuery();
    }
    catch (Exception e)
    {

    }
    finally
    {
        con.Close();
    }

}

HTTP POST request in HTML:

$scope.add_to_db = function () 
{                                
    //insert contact to db
    $http.post(url + "/api/Contacts",
        JSON.stringify({ Name: $scope.contactName, Phone: $scope.contactPhone, Mail: $scope.contactMail, City: $scope.contactCity, Address: $scope.contactAddress}))
        .then(function (res) {
            $state.go("contacts");
    }, function (err) { alert(err); });
}

The response is returned to the success function but nothing's changed in the database. What could be the problem here?

Answer 1

Catch Block is Empty to know the error, Usually i go through these scenarios and i make sure the following are implemented in the code to track down the failure reason:

1) @RequestBody in API controller should be accepting Contact model data.

2) Check if JSON object created at angular is in sync with Contact model/ POJO.

3) Use POSTMAN to debug only REST API initially, which can help you to track down failure.