title: Syntax error: missing expression (ORA-00936)
body: <p>I have 2 tables, <code>Facilities</code> and <code>Services</code>. </p>
  
  <pre><code>CREATE TABLE Facilities (
  facility_id NUMBER(2) NOT NULL,
  facility_name VARCHAR2(20) NOT NULL,
  CONSTRAINT pk_facil_id PRIMARY KEY (facility_id)
  );
  
  CREATE TABLE Services (
  service_id NUMBER(2) NOT NULL,
  service_name VARCHAR(20) NOT NULL,
  service_facility NUMBER(2) NOT NULL,
  CONSTRAINT pk_serviceid PRIMARY KEY (service_id)
  );
  
  ALTER TABLE Services
  add CONSTRAINT fk_servicefacility FOREIGN KEY(service_facility) 
  REFERENCES Facilities(facility_id);
  </code></pre>
  
  <p>If I try entering records into the 'Services' table like so:</p>
  
  <pre><code>INSERT INTO Services (service_id, service_name, service_facility) 
  SELECT 06, 'Rooms', 
  (SELECT facility_id, FROM Facilities WHERE facility_name = 'Hotel') 
  FROM Dual;
  </code></pre>
  
  <p>I get an error "missing expression" for 3 out of the 7 insert statements. What expression is missing?</p>