public static void Update()
{
string query = "UPDATE users SET";
string query_firstname = "";
string query_lastname = "";
string query_favoritenumber = "";
bool a = false;
bool c = false;
bool b = false;
Console.WriteLine("Want to update database? (yes/no)");
string confir = Console.ReadLine();
if (confir == "yes")
{
Console.WriteLine("Which user do you want to update ? (type in user ID)");
string ID = Console.ReadLine();
var temp1 = DbConnector.Query($"SELECT COUNT(id) FROM users WHERE id = {ID}"); //check if this user exists, by using Count(), return List<Dictionary<string,object>>
List <object> temp2 = temp1[0].Values.ToList(); //get first value which is number of how many matches, USING SYSTEM.LINQ IN ORDER TO USE ToList() to convert KeyCollction to List
int existance = Convert.ToInt32(temp2[0]); //Error:"Unable to cast object of type 'System.Int64' to type 'System.Int32'."
if (existance != 0)
{
Console.WriteLine("want to update first name?(type first name or just type no)");
string first_name = Console.ReadLine();
if (first_name != "no")
{
query_firstname = $" first_name = '{first_name}'";
}
else
{
a = true;
}
Console.WriteLine("want to update last name?(type last name or no)");
string last_name = Console.ReadLine();
if (last_name != "no")
{
query_lastname = $" ,last_name = '{last_name}'";
}
else
{
b = true;
}
Console.WriteLine("want to update favorite number(type number or no)");
string favoritenumber = Console.ReadLine();
if (favoritenumber != "no")
{
query_favoritenumber = $" ,favoritenumber = {favoritenumber}";
}
else
{
c = true;
}
if (a && b && c)
{
Console.WriteLine(" You did not input, update fails !");
}
else
{
query = query + query_firstname + query_lastname + query_favoritenumber + $" WHERE id = {ID}";
Console.WriteLine(query);
DbConnector.Query(query);
}
}
else
{
Console.WriteLine("Record does not exist!");
}
}
}