 -- Meta data for a production
 -- see http://www.daisy.org/z3986/2005/Z3986-2005.html#PubMed
 CREATE TABLE production (
-  id INTEGER PRIMARY KEY,
-  title TEXT,
+  id INTEGER AUTO_INCREMENT PRIMARY KEY,
+  title TEXT NOT NULL,
   creator TEXT,
   subject TEXT,
   description TEXT,
-  publisher TEXT,
-  date TEXT,
+  publisher TEXT NOT NULL,
+  date TEXT NOT NULL,
   type TEXT,
   format TEXT,
-  identifier TEXT,
+  identifier TEXT NOT NULL,
   source TEXT,
-  language TEXT,
+  language TEXT NOT NULL,
   rights TEXT,
   source_date TEXT,
   source_edition TEXT,

);

CREATE TABLE product (
  id INTEGER PRIMARY KEY,
  identifier TEXT NOT NULL,
  type INTEGER NOT NULL,
  production_id INTEGER NOT NULL,

);

CREATE TABLE role (
  id INTEGER AUTO_INCREMENT PRIMARY KEY,
  name TEXT NOT NULL
);

CREATE TABLE user_role (
  id INTEGER AUTO_INCREMENT PRIMARY KEY,
  user_id INTEGER NOT NULL,
  role_id INTEGER NOT NULL,
  FOREIGN KEY(user_id) REFERENCES user(id),
