# Write Operations

Entities can be inserted into a repository using insert() or insertMay() method. It takes one or multiple Dart entities as input parameter respectively. It returns a future of WriteResult object.

If the entity has a NitriteId field, then the field value would be populated with a new NitriteId before inserting into the repository.

If any of the field is already indexed in the repository, then the index will be updated accordingly.

var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 600.0;

var result = await productRepository.insert(product);

var product1 = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 600.0;

var product2 = Product()
    ..productId = ProductId(2)
    ..productName = 'Apple iPhone 6 Plus'
    ..price = 700.0;

var result = await productRepository.insertMany([product1, product2]);

• If a field of the entity is unique indexed and it's value violates the index constraint, then it will throw a UniqueConstraintException.

More information about WriteResult can be found here.

Entities can be updated using any of the following methods:

• updateOne() - updates a single entity
• update() - updates multiple entities using a filter and update entity
• updateDocument() - updates multiple entities using a filter and update document

All update methods returns a Future<WriteResult> object.

You can update a single entity using updateOne() method. It takes a Dart entity as input parameter. It returns a Future<WriteResult> object. The entity must have a valid id field.

```dart
var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 600.0;

var result = await productRepository.insert(product);

product.price = 700.0;

result = await productRepository.updateOne(product);

You can also upsert a single entity using updateOne() method. Along with the entity parameter, you need to pass a named parameter insertIfAbsent with value true. If the entity does not exist in the repository, then it will be inserted. Otherwise, it will be updated. The default value of insertIfAbsent is false.

var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 600.0;

var result = await productRepository.updateOne(product, insertIfAbsent: true);

You can update multiple entities using a filter. It takes a Filter object as first input parameter. It takes a Dart entity as second input parameter. It returns a Future<WriteResult> object.

If the filter result matches multiple entities, then all the entities will be updated.

var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 650.0;

var result = await productRepository.update(where('productName').eq('Apple iPhone 6'), product);

You can update multiple entities using a filter and options. It takes a Filter object as first input parameter. It takes a Dart entity as second input parameter. It takes a UpdateOptions object as third input parameter. It returns a Future<WriteResult> object.

More information about UpdateOptions can be found here.

var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 650.0;

var updateOptions = UpdateOptions();
updateOptions.insertIfAbsent = true;

var result = await productRepository.update(where('productName').eq('Apple iPhone 6'), product, updateOptions);

You can update multiple entities using a filter. It takes a Filter object as first input parameter. It takes a Document object as second input parameter. It returns a Future<WriteResult> object.

If the filter result matches multiple entities, then all the entities will be updated. The document must contain only the fields that needs to be updated.

var update = createDocument('price', 700);

var result = await productRepository.updateDocument(where('productName').eq('Apple iPhone 6'), update);

You can update multiple entities using a filter, document and options. It takes a Filter object as first input parameter. It takes a Document object as second input parameter. It takes a boolean value as third input parameter. If the third input parameter is true, then it will only update the first entity matched by the filter. Otherwise, it will update all the entities matched by the filter. It returns a Future<WriteResult> object.

The document must contain only the fields that needs to be updated.

var update = createDocument('price', 700);

var result = await productRepository.updateDocument(where('productName').eq('Apple iPhone 6'), update, justOnce: true);

Entities can be removed using any of the following methods:

• removeOne() - removes a single entity
• remove() - removes multiple entities using a filter

All remove methods returns a Future<WriteResult> object.

You can remove a single entity using removeOne() method. It takes a Dart entity as input parameter. It returns a Future<WriteResult> object.

The entity must have a valid id field marked with @Id annotation. In case an EntityDecorator is used, the idField getter must return a valid non-null EntityId object. Otherwise, it will throw a NotIdentifiableException.

var product = Product()
  ..productId = ProductId(1)
  ..productName = 'Apple iPhone 6'
  ..price = 600.0;

var result = await productRepository.insert(product);

result = await productRepository.removeOne(product);

You can remove multiple entities using a filter. It takes a Filter object as input parameter. It returns a Future<WriteResult> object.

If the filter result matches multiple entities, then all the entities will be removed.

var result = await productRepository.remove(where('productName').eq('Apple iPhone 6'));

You can remove multiple entities using a filter and options. It takes a Filter object as first input parameter. It takes a boolean value as second input parameter. If the second input parameter is true, then it will remove only the first entity matched by the filter. Otherwise, it will remove all the entities matched by the filter. It returns a Future<WriteResult> object.

var result = await productRepository.remove(where('productName').eq('Apple iPhone 6'), justOne: true);