add new example 'qsqlite': use SQL from Lisp, load QML images from DB

examples/qsqlite/lisp/db.lisp

@@ -0,0 +1,34 @@
+(in-package :db)
+
+(defvar *file* nil)
+
+(defun query (query &rest values)
+  (let ((rows (and (x:starts-with "select" query)
+                   (1+ (count #\, (subseq query 0 (search "from" query)))))))
+    (qrun* (qt:sql-query qt:*cpp* query values rows))))
+
+(defun ini ()
+  (setf *file* (app:in-data-path "db"))
+  (ensure-directories-exist *file*)
+  (qt:ini-db qt:*cpp* (namestring *file*) *quick-view*)
+  (query "create table if not exists images (id integer primary key autoincrement, name text, data blob)"))
+
+(defun size ()
+  (first (query "select count(*) from images")))
+
+(defun save-image (name data)
+  "Inserts image NAME, DATA (vector of octets) and returns the new image ID."
+  (first (query "insert into images (name, data) values (?, ?)"
+                name data)))
+
+(defun load-images ()
+  (query "select name, data from images order by id"))
+
+(defun delete-image (id)
+  (query "delete from images where id = ?"
+         id)
+  (values))
+
+(defun delete-all-images ()
+  (query "delete from images"))
+