1.3 Overview

The conceptual schema definition language (CSDL) is an XML-based file format that describes the Entity Data Model (EDM). CSDL is based on standards defined in [XML1.0] and [XMLSCHEMA1]. The root of the CSDL is a Schema element. Following that root, these child elements are supported: Using, EntityType, ComplexType, Association, and EntityContainer. In CSDL 2.0 and CSDL 3.0, Schema elements can have Function as a child element. EntityContainer elements conceptually represent a DataSource and can contain EntitySet, AssociationSet, and FunctionImport as child elements. In CSDL 3.0, Schema elements can have ValueTerm and Annotations as child elements.

Conceptually, a CSDL file has an overall structure that resembles the following schema.

 <Schema>
    <Using/>
    <Using/>
    <Annotations />
    <ValueTerm />
  
    <EntityType/>
    <EntityType/>
    <ComplexType/>
  
    <Association/>
    <Association/>
    <Function/>
    <Function/>
    <EntityContainer>
       <EntitySet/>
       <EntitySet/>
  
       <AssociationSet/>
       <AssociationSet/>
  
       <FunctionImport/>
       <FunctionImport/>
    </EntityContainer>
    <EntityContainer/>
 </Schema>
  

Note The previous example is not a detailed specification. It is meant to provide only a visual overview.