Class DefaultValueAttribute
The value existing records take when this member is added to a model that is already in production.
On a relational store the column arrives with it as its default; on a document store it is written
into the documents that predate the member. That second case is the one that bites: a document
without the element does not fail to load, it loads as default(T) — an enum becomes its first
value, a date becomes 0001-01-01 — so the data is quietly wrong rather than loudly missing.
The value belongs to the domain, not to the schema, which is why the engine will not invent one: a member added without it produces a change that refuses to run until you say what the existing records should hold.
[AttributeUsage(AttributeTargets.Property)]
public sealed class DefaultValueAttribute : Attribute- Inheritance
-
DefaultValueAttribute
- Inherited Members
Constructors
DefaultValueAttribute(object)
The value existing records take when this member is added to a model that is already in production.
On a relational store the column arrives with it as its default; on a document store it is written
into the documents that predate the member. That second case is the one that bites: a document
without the element does not fail to load, it loads as default(T) — an enum becomes its first
value, a date becomes 0001-01-01 — so the data is quietly wrong rather than loudly missing.
The value belongs to the domain, not to the schema, which is why the engine will not invent one: a member added without it produces a change that refuses to run until you say what the existing records should hold.
public DefaultValueAttribute(object value)Parameters
valueobject
Properties
Value
The value existing records take.
public object Value { get; }