How to update an existing data without interrupting all other data of a database table using ternary operator in c# dot net

Question

I am creating a Web API which will do CRUD operation. I have defined all the methods to CRUD but I am facing an issue when I try to update a data in db then either I had to pass all columns data else it is updating the columns with null and I want to do the null checking using ternary operator.

`Here is what I tried my code

In my DbContext class I have initialized all the parameters with null`

public bool UpdateEmployee(int  empID, EmpModel emp) 
        {
            SqlCommand cmd = new SqlCommand("Sp_UpdateEmployee", con);
            cmd.CommandType= CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@ID", empID);
            cmd.Parameters.AddWithValue("@FirstName",emp.FirstName=null);
            cmd.Parameters.AddWithValue("@LastName", emp.LastName=null);
            cmd.Parameters.AddWithValue("@Gender", emp.Gender = null);
            cmd.Parameters.AddWithValue("@Salary", emp.Salary=0);
            cmd.Parameters.AddWithValue("@DeptId", emp.DeptId=0);
            con.Open() ;
            int i=cmd.ExecuteNonQuery();
            con.Close();

            if(i>=1) return true;
            else return false;
        }

In Controller class passing the updated id which is identical and the model class object.

[HttpPut]
        public void Put(int id,EmpModel emp)
        {
            if (ModelState.IsValid == true)
                db.UpdateEmployee(id,emp);
        }

my stored procedure in sql server also I have given null checking and it is working fine in Sql server

ALTER PROCEDURE [dbo].[Sp_UpdateEmployee]
    
    @ID int,
    @FirstName varchar(100)=null,
    @LastName varchar(50)=null,
    @Gender varchar(20)=null,
    @Salary bigint=null,
    @DeptId int=null
AS
BEGIN
    
    SET NOCOUNT ON;

    update Employee set FirstName=Isnull(@FirstName,FirstName),LastName=Isnull(@LastName,LastName),
    Gender=Isnull(@Gender,Gender),Salary=Isnull(@Salary,Salary),DeptId=Isnull(@DeptId,DeptId)
    where ID=@ID
END

Here is the model class where I am getting the error


private string _firstname;
        public string FirstName 
        {
            get=> _firstname; 
            set=>FirstName=_firstname.ToString()==""? null:_firstname.ToString();
        }

'In the model class where I am setting the property I am getting nullReferenceException which shows that I am passing null value but in database I have all the data present in the table so I am not getting why this exception is showing.'


    set=>FirstName=_firstname.ToString()==""? null:_firstname.ToString();

I am getting error NullReferenceException Can anybody guide me where I am making mistake?

How to update an existing data without interrupting all other data of a database table using ternary operator in c# dot net

0 Answers0