[求助]字段定义

请问在字段定义时BLOB和GUID分别表示什么类型？

<P>blob 是images or other multimedia。更详细的A BLOB, or binary large object, is simply some data stored in the geodatabase as a long sequence of binary numbers. Items such as images, multimedia, or bits of code can be stored in this type of field。</P><P>GUID是Global identifier fields。更详细的GlobalID and GUID data types store registry style strings that uniquely identify a feature or table row within a geodatabase and across geodatabases. Developers can use them in relationships or in any application requiring globally unique identifiers. In a relationship, if a GlobalID field is the origin key, a GUID field must be the destination key. You must add the GlobalID field programmatically, however, once you add it ArcGIS maintains its values. You can create the GUID field in ArcCatalog but you must maintain its values.</P>