在SQL中不区分大小写保存吗？

Question

On my login form after i save my content to SQL and if i try to get the information from the database the information passes the evaluation to true even if the information provided is typed both ways - upper case or lower case.Here is my login code,please help me understand.I'am contacting database with Entity Framework.the currUser is a variable where I save the current user information.

try
      {
          if (!string.IsNullOrWhiteSpace(username) && !string.IsNullOrWhiteSpace(password))
          {
              var users = from c in context.CustomerTables where c.username == username && c.password == password select c;
              List<CustomerTable> table = users.ToList();
              if (table.Any())
              {
                  MessageBox.Show("Successfully logged in.\nWelcome " + username + "!", "Welcome", MessageBoxButton.OK, MessageBoxImage.Asterisk);
                  currUser.username = username;
                  currUser.password = password;
                  return true;
              }
              else
              {
                  MessageBox.Show("Username or password is invalid.", "Error logging in", MessageBoxButton.OK, MessageBoxImage.Error);
                  return false;
              }
          }
          else
          {
              MessageBox.Show("Username and password format is invalid!","Null username or password",MessageBoxButton.OK,MessageBoxImage.Warning);
              return false;
          }

Answer 1

The simplest fix would be to replace

if (table.Any())

with

if (table.Any() && table[0].username == username && table[0].password == password)

The reason why this would work is that string comparison in C# is case-sensitive by default.