make a refetch to a graphql server after mutation complete code example

Example 1: usemutation apollo

import { gql, useMutation } from '@apollo/client';

const ADD_TODO = gql`
  mutation AddTodo($type: String!) {
    addTodo(type: $type) {
      id
      type
    }
  }
`;


function AddTodo() {
  let input;
  const [addTodo, { data }] = useMutation(ADD_TODO);

  return (
    

      
 {
          e.preventDefault();
          addTodo({ variables: { type: input.value } });
          input.value = '';
        }}
      >
         {
            input = node;
          }}
        />
        Add Todo
      
    
  );
}

Example 2: apollo graphql mutation hook

const UPDATE_TODO = gql`
  mutation UpdateTodo($id: String!, $type: String!) {
    updateTodo(id: $id, type: $type) {
      id
      type
    }
  }
`;

function Todos() {
  const { loading, error, data } = useQuery(GET_TODOS);
  const [updateTodo] = useMutation(UPDATE_TODO);

  if (loading) return 
Loading...
;
  if (error) return 
Error :(
;

  return data.todos.map(({ id, type }) => {
    let input;

    return (
      

        
{type}
        
 {
            e.preventDefault();
            updateTodo({ variables: { id, type: input.value } });
            input.value = '';
          }}
        >
           {
              input = node;
            }}
          />
          Update Todo
        
      
    );
  });
}