C# – Read, Insert, Update, Delete From SQL Database

C# – Read, Insert, Update, Delete From SQL Database

Code snippets for reading, inserting, updating and deleting from SQL database.

static void Read()
{
    try
    {
        string connectionString =
            "server=.;" +
            "initial catalog=employee;" +
            "user id=sa;" +
            "password=sa123";
        using (SqlConnection conn =
            new SqlConnection(connectionString))
        {
            conn.Open();
            using (SqlCommand cmd =
                new SqlCommand("SELECT * FROM EmployeeDetails", conn))
            {
                SqlDataReader reader = cmd.ExecuteReader();

                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        Console.WriteLine("Id = ", reader["Id"]);
                        Console.WriteLine("Name = ", reader["Name"]);
                        Console.WriteLine("Address = ", reader["Address"]);
                    }
                }

                reader.Close();
            }
        }
    }
    catch (SqlException ex)
    {
        //Log exception
        //Display Error message
    }
}

static void Insert()
{
    try
    {
        string connectionString =
            "server=.;" +
            "initial catalog=employee;" +
            "user id=sa;" +
            "password=sa123";
        using (SqlConnection conn =
            new SqlConnection(connectionString))
        {
            conn.Open();
            using (SqlCommand cmd =
                new SqlCommand("INSERT INTO EmployeeDetails VALUES(" +
                    "@Id, @Name, @Address)", conn))
            {
                cmd.Parameters.AddWithValue("@Id", 1);
                cmd.Parameters.AddWithValue("@Name", "Amal Hashim");
                cmd.Parameters.AddWithValue("@Address", "Bangalore");

                int rows = cmd.ExecuteNonQuery();

                //rows number of record got inserted
            }
        }
    }
    catch (SqlException ex)
    {
        //Log exception
        //Display Error message
    }
}

static void Update()
{
    try
    {
        string connectionString =
            "server=.;" +
            "initial catalog=employee;" +
            "user id=sa;" +
            "password=sa123";
        using (SqlConnection conn =
            new SqlConnection(connectionString))
        {
            conn.Open();
            using (SqlCommand cmd =
                new SqlCommand("UPDATE EmployeeDetails SET Name=@NewName, Address=@NewAddress" +
                    " WHERE Id=@Id", conn))
            {
                cmd.Parameters.AddWithValue("@Id", 1);
                cmd.Parameters.AddWithValue("@Name", "Munna Hussain");
                cmd.Parameters.AddWithValue("@Address", "Kerala");

                int rows = cmd.ExecuteNonQuery();

                //rows number of record got updated
            }
        }
    }
    catch (SqlException ex)
    {
        //Log exception
        //Display Error message
    }
}

static void Delete()
{
    try
    {
        string connectionString =
            "server=.;" +
            "initial catalog=employee;" +
            "user id=sa;" +
            "password=sa123";
        using (SqlConnection conn =
            new SqlConnection(connectionString))
        {
            conn.Open();
            using (SqlCommand cmd =
                new SqlCommand("DELETE FROM EmployeeDetails " +
                    "WHERE Id=@Id", conn))
            {
                cmd.Parameters.AddWithValue("@Id", 1);
                
                int rows = cmd.ExecuteNonQuery();

                //rows number of record got deleted
            }
        }
    }
    catch (SqlException ex)
    {
        //Log exception
        //Display Error message
    }
}