query
const GET_BOOKS = gql`
query {
  books {
  name
  genre
  }
}
`;
Entity name: 'books'
An object has multiple keys, for instance, {__typename:'Book", name:'Harry Portal", genre:"Fiction"} ,

update an object in local cache with keys instead of 'id' field

// Update a record without 'id' field in local cache
// for instance, the entity is "books", and the record is below:
// __typename: "Book"
// name: "grapes 🍇 delicious"
// genre: "Fiction"
// updateCachedRecordWithoutId('books',{name:'oldname'},{name:'newname',age:12})
updateCachedRecordWithoutId>(
cacheEntity: string,
filter: T,
data: T
): void {
this.apollo.client.cache.modify({
id: 'ROOT_QUERY',
fields: {
[cacheEntity]: (items = []) => {
  const oldItems = cloneDeep(items);
  const index = oldItems.findIndex((rec: T) =>
  Object.keys(filter).every((key) => {
    const k = key as keyof T;
    return rec[k] === filter[k];
  })
  );
  if (index < 0) return items;
  const newItems = cloneDeep(items);
  newItems[index] = { ...newItems[index], ...data };
  return newItems;
  },
},
});
}
Remove an object from an entity with keys instead of 'id' field

/**
* Remove a record without 'id' field from an entity in apollo cache
* This method is used when you need to remove the cache with a custom key.
*
* @param cacheEntity The name of the entity in the cache.
* @param filter The key or keys of the entity you want to update.
* @example
* removeCachedRecordWithoudId('workorderliness', { workOrderNo:'abcd',lineNo:10000});
* */
removeCachedRecordWithoudId(
  cacheEntity: string,
  filter: Partial extends object ? Partial : never
): void {
this.apollo.client.cache.modify({
  id: 'ROOT_QUERY',
  fields: {
    [cacheEntity]: (items = [], { DELETE }) => {
    const oldItems = cloneDeep(items);
    const newItems = oldItems.filter(
    (rec: T) =>
      !Object.keys(filter).every((key) => {
      const k = key as keyof T;
      return rec[k] === filter[k];
    })
  );
  // If the record is empty, delete it.
  // This is to prevent the cache from returning an empty array. Which causes an error when adding a f
  if (newItems.length === 0) return DELETE;
  return newItems;
  },
  },
  });
}

query
const GET_BOOKS = gql`
query {
  books {
    id
    name
    genre
    }
  }
`;
Entity name: 'books'
In Apollo cache, An object has only one key, for instance, {__ref:'Book:640555"} ,

/**
* Update a single record using id in apollo cache.
*
* @param objectName The name of the object in the cache, which is capitalized, such as 'Book'. However, the
* @param id The id of the object, which is unique for the entity, refering to the record in local cache, s
* @param data The data to update the entity with.
* @example
* updateCachedRecordById('Book', '1233', {age: 12, name: 'New Name' });
*
*/
updateCachedRecordById>(
  objectName: string,
  id: string,
  data: T
): void {
  const fields = Object.keys(data)
  .map((field) => `${field}`)
  .join('\n');
  // MyObject is a random fragment name, which can be any name,but should be constant instead of a variable
  const fragmentQuery = gql`
  fragment MyObject on ${objectName} {
    ${fields}
  }
  `;
  this.apollo.client.writeFragment({
  id: objectName + ':' + id,
  fragment: fragmentQuery,
  data: data,
  });
}
/**
* Remove a record using id from an entity in Apollo cache .
* This method is limited to entities with an 'id' field.
*
* @param cacheEntity The name of the entity in the cache.
* @param id The id of the entity.
* @example
* removeCachedRecordByid('equipments', '1233');
*
*/
removeCachedRecordByid(cacheEntity: string, id: string): void {
  this.apollo.client.cache.modify({
  id: 'ROOT_QUERY',
fields: {
  [cacheEntity]: (items: { __ref: string }[] = [], { readField }) => {
  const i = items.findIndex(
    (rec: { __ref: string }) => readField('id', rec) === id
  );
  if (i < 0) return items;
    const newRecords = cloneDeep(items);
    newRecords.splice(i, 1);
    return newRecords;
  },
  },
  });
}