[Option] ReadSchema [Description] 
Reads any inline schema and loads the data and schema. If the DataSet already contains a schema, new tables are added from the inline schema to the existing schema in the DataSet. If any tables in the inline schema already exist in the DataSet, an exception is thrown. You will not be able to modify the schema of an existing table using XmlReadMode.ReadSchema. If the DataSet does not contain a schema, and there is no inline schema, no data is read. Inline schema can be defined using XML Schema definition language (XSD) schema. For details about writing inline schema as XML Schema, see Deriving DataSet Relational Structure from XML Schema (XSD).