ODBC
When an XML Schema is generated from an ODBC database (DB), the ODBC DB datatypes are converted to XML Schema datatypes as listed in the table below.
ODBC Datatype  | XML Schema Datatype  | 
SQL_GUID  | xs:ID  | 
SQL_CHAR  | xs:string  | 
SQL_VARCHAR  | xs:string  | 
SQL_LONGVARCHAR  | xs:string  | 
SQL_BIT  | xs:boolean  | 
SQL_REAL  | xs:float  | 
SQL_DOUBLE  | xs:double  | 
SQL_DECIMAL  | xs:decimal  | 
SQL_TIMESTAMP  | xs:dateTime  | 
SQL_DATE  | xs:date  | 
SQL_BINARY  | xs:base64Binary  | 
SQL_VARBINARY  | xs:base64Binary  | 
SQL_LONGVARBINARY  | xs:base64Binary  | 
SQL_INTEGER  | xs:integer  | 
SQL_SMALLINT  | xs:short  | 
SQL_BIGINT  | xs:long  | 
SQL_TINYINT  | xs:byte  |