+;;; Database backend capabilities
+
+(defgeneric database-underlying-type (database)
+ (:method (database)
+ (database-type database))
+ (:documentation "Returns the type of the underlying database. For ODBC, needs to query ODBC driver."))
+
+(defgeneric db-type-use-column-on-drop-index? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ nil)
+ (:documentation "NIL [default] if database-type does not use column name on DROP INDEX."))
+
+(defgeneric db-type-has-views? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ ;; SQL92 has views
+ t)
+ (:documentation "T [default] if database-type supports views."))
+
+(defgeneric db-type-default-case (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ ;; By default, CommonSQL converts identifiers to UPPER case.
+ :upper)
+ (:documentation ":upper [default] if means identifiers mapped to UPPER case SQL like CommonSQL API. However, Postgresql maps identifiers to lower case, so PostgreSQL uses a value of :lower for this result."))
+
+(defgeneric db-type-has-fancy-math? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ nil)
+ (:documentation "NIL [default] if database-type does not have fancy math."))
+
+(defgeneric db-type-has-subqueries? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ t)
+ (:documentation "T [default] if database-type supports views."))
+
+(defgeneric db-type-has-boolean-where? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ ;; SQL99 has boolean where
+ t)
+ (:documentation "T [default] if database-type supports boolean WHERE clause, such as 'WHERE MARRIED'."))
+
+(defgeneric db-backend-has-create/destroy-db? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ t)
+ (:documentation "T [default] if backend can destroy and create databases."))
+
+(defgeneric db-type-transaction-capable? (db database)
+ (:method (db database)
+ (declare (ignore db database))
+ t)
+ (:documentation "T [default] if database can supports transactions."))