17. A method of operating a computer system to create a relational database schema from a semantic object model, comprising the steps of: creating, in response to a user input, one or more semantic objects each of which represents an item about which data is stored in a relational database; creating in response to a user input one or more attributes and associating the attributes with a semantic object, each of the attributes representing data stored in the relational database for the item represented by the semantic object, the attributes including simple value attributes that represent a single data entry in a column of the relational database, group attributes having one or more member attributes that represent a logical collection of attributes and object link attributes that represent relationships between the semantic objects in the semantic object model, wherein the computer system stores for each object link attribute an ID status property that defines whether one semantic object in the semantic object model is uniquely defined by another semantic object in the semantic object model; automatically validating the semantic object model to determine if a modeling error has occurred by performing the steps of: 1) determining if a first semantic object in the object model includes an object link attribute having an ID status property that indicates the first semantic object is uniquely defined by a second semantic object in the object model; and 2) determining if the second semantic object includes an object link attribute having an ID status property that indicates the second semantic object is uniquely defined by the first semantic object; and if conditions 1 and 2 do not occur, translating the semantic objects and their associated attributes in the semantic object model into a relational database schema.
17. A method of operating a computer system to create a relational database schema from a semantic object model, comprising the steps of: creating, in response to a user input, one or more semantic objects each of which represents an item about which data is stored in a relational database; creating in response to a user input one or more attributes and associating the attributes with a semantic object, each of the attributes representing data stored in the relational database for the item represented by the semantic object, the attributes including simple value attributes that represent a single data entry in a column of the relational database, group attributes having one or more member attributes that represent a logical collection of attributes and object link attributes that represent relationships between the semantic objects in the semantic object model, wherein the computer system stores for each object link attribute an ID status property that defines whether one semantic object in the semantic object model is uniquely defined by another semantic object in the semantic object model; automatically validating the semantic object model to determine if a modeling error has occurred by performing the steps of: 1) determining if a first semantic object in the object model includes an object link attribute having an ID status property that indicates the first semantic object is uniquely defined by a second semantic object in the object model; and 2) determining if the second semantic object includes an object link attribute having an ID status property that indicates the second semantic object is uniquely defined by the first semantic object; and if conditions 1 and 2 do not occur, translating the semantic objects and their associated attributes in the semantic object model into a relational database schema. 18. The method of claim 17, wherein the step of validating the semantic object model further comprises the step of: automatically analyzing each semantic object in the semantic object model to determine whether any semantic objects are not associated with any object link attributes.