{"id":213,"date":"2014-07-23T20:22:00","date_gmt":"2014-07-23T20:22:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/odatateam\/2014\/07\/23\/tutorial-sample-using-unsigned-integers-in-odata\/"},"modified":"2020-01-07T04:47:31","modified_gmt":"2020-01-07T11:47:31","slug":"tutorial-sample-using-unsigned-integers-in-odata","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/odata\/tutorial-sample-using-unsigned-integers-in-odata\/","title":{"rendered":"[Tutorial & Sample] Using Unsigned Integers in OData"},"content":{"rendered":"

Unsigned integers can be useful in many ways, such as representing data sizes, resource handles <\/span>and so on. Though OData V4 only supports signed integer natively, the protocol offers a flexible way called type definition to allow users to \u2018define\u2019 unsigned integer types themselves.<\/span><\/p>\n

As an example, we know that any UInt16<\/em> integer can be represented by the primitive type Edm.Int32<\/em>. Thus by type definition, we can define a new type named MyNamespace.UInt16<\/em> whose underlying type is Edm.Int32<\/em>. By doing so, we can store and serialize UInt16<\/em> integers as Edm.Int32<\/em> ones. There are three advantages of leveraging type definition here:<\/p>\n

(1)\u00a0\u00a0\u00a0 Prevent breaking clients who conform to the protocol (to recognize type definitions) but are unaware of unsigned integer types.<\/p>\n

(2)\u00a0\u00a0\u00a0 Give the underlying type a different name that is meaningful to the context.<\/p>\n

(3)\u00a0\u00a0\u00a0 Enable the flexibility to change the underlying type without breaking the \u2018unsigned integer\u2019 type semantics.<\/p>\n

From version 6.5.0, our OData library starts to provide built-in support for unsigned integer types (including UInt16<\/em>, UInt32<\/em> and UInt64<\/em> for now) as a protocol extension. Generally a user would have to write very little code to gain a workable model with default implementation of unsigned integers. Meanwhile, the library is flexible that users are allowed to use their customized implementation as well.<\/p>\n

Introducing Type Definition<\/h2>\n

Before diving into unsigned integers, let\u2019s first take a look at how to define and use type definitions in OData. Suppose we want to define a new type Height<\/em> whose underlying type is Edm.Double<\/em> and use it to define a property MyHeight<\/em> in an entity type Person <\/em>(it is the same for complex type).<\/p>\n

We can write the following CSDL for the model:<\/p>\n