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6. Datastore Queries > Unset and Nonindexed Properties

Unset and Nonindexed Properties

As you’ve seen, an index contains columns of property values. Typically, an app creates entities of the same kind with the same set of properties: every Player in our game has a name, a character class, a level, and a score. If every entity of a kind has a given property, then an index for that kind and property has a row corresponding to each entity of the kind.

But the datastore neither requires nor enforces a common layout of properties across entities of a kind. It’s quite possible for an entity to not have a property that other entities of the same kind have. For instance, a Player entity might be created without a character class, and go without until the user chooses one.


  

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