Write locks ensure that when you update a data item, you can't overwrite changes from somewhere else. For example, if there are changes in a different part of your code, or from a Cloud Code script.

For an example of how to use a write lock, refer to the

SaveItem

class in the Cloud Save SDK.

Read and write commands both return a , which you can store locally. When you save a value, you can include the that you obtained. If the write lock doesn't match what's in the Cloud Save service, the service returns an error to indicate that the value in the service has been updated since the last time you retrieved the write lock.

If you encounter a write lock error, you can proceed with one of the following:

To avoid unnecessary errors, you need to omit the field when you create a new data item.

To skip write lock validation, you can set the field for an item to . A null write lock means that you overwrite any existing value stored for that item.