title: pgAdmin - When trying to make a foreign key "referencing" gives no options
body: <p>I have three tables: <code>ModelingAgency.clients</code>, <code>ModelingAgency.models</code>, <code>ModelingAgency.Bookings</code>. All three tables have a primary key column called <code>id</code>.</p>
  
  <p>The table <code>bookings</code> has two columns that reference <code>clients</code> and <code>models</code>. In pgAdmin when I try to create a foreign key in <code>bookings</code> to either <code>clients</code> or <code>models</code> I get the following screens:</p>
  
  <p><img src="https://i.stack.imgur.com/gGCZV.png" alt="Screen One"></p>
  
  <p><img src="https://i.stack.imgur.com/rlDos.png" alt="Screen Two"></p>
  
  <p>What am I overlooking here? I am new to PostgreSQL (This is my first test project with PostgreSQL -- I've always used MySQL and occasionally SQL Server) so it's probably something obvious (I just don't see it).</p>
  
  <p><strong>EDIT:</strong> Here is the DDL, as requested:</p>
  
  <pre><code>-- Table: "ModelingAgency.bookings"
  
  -- DROP TABLE "ModelingAgency.bookings";
  
  CREATE TABLE "ModelingAgency.bookings"
  (
    id integer NOT NULL DEFAULT nextval('"ModelingAgency.Bookings_id_seq"'::regclass),
    "clientId" integer NOT NULL,
    "modelId" integer NOT NULL,
    "time" timestamp with time zone NOT NULL DEFAULT now(),
    "location" character varying(100) NOT NULL DEFAULT 'No Location Selected'::character varying,
    CONSTRAINT "bookingId" PRIMARY KEY (id)
  )
  WITH (
    OIDS=FALSE
  );
  ALTER TABLE "ModelingAgency.bookings" OWNER TO "MyBatisTutorial";
  
  
  -- Table: "ModelingAgency.clients"
  
  -- DROP TABLE "ModelingAgency.clients";
  
  CREATE TABLE "ModelingAgency.clients"
  (
    id integer NOT NULL DEFAULT nextval('"ModelAgency.clients_id_seq"'::regclass),
    "name" character varying(45) NOT NULL,
    CONSTRAINT "clientId" PRIMARY KEY (id)
  )
  WITH (
    OIDS=FALSE
  );
  ALTER TABLE "ModelingAgency.clients" OWNER TO "MyBatisTutorial";
  
  
  -- Table: "ModelingAgency.models"
  
  -- DROP TABLE "ModelingAgency.models";
  
  CREATE TABLE "ModelingAgency.models"
  (
    id serial NOT NULL,
    "name" character varying(45) NOT NULL,
    CONSTRAINT "modelId" PRIMARY KEY (id)
  )
  WITH (
    OIDS=FALSE
  );
  ALTER TABLE "ModelingAgency.models" OWNER TO "MyBatisTutorial";
  </code></pre>