Module NewEntity

Provides predicates and types for allocating new entity IDs dynamically in upgrade and downgrade scripts.

The module has a type parameter T and contains a predicate map and a type EntityId. The map predicate maps a T value to an opaque EntityId value, which can be used as a new entity ID in new database rows.

Predicates

map

Maps each T value to an EntityId value. Different T values map to different EntityId values. Instantiating the module with different type arguments for T causes map to generate different entity IDs. Instantiating the module in different database upgrade or downgrade queries also causes map to generate different entity IDs.

Primitive types

EntityId

EntityId values can be used as database entity IDs.

Module NewEntity

Predicates

Primitive types

Parameters