title: Foreign Key Constraint does not exist ERROR
body: <p>I keep getting this error in my psql database;</p>
  
  <pre><code>bikefacility=# ERROR:  syntax error at or near "c"
  bikefacility-# LINE 1: c
  bikefacility-#         ^
  bikefacility-# bikefacility=# ALTER TABLE bicycle ADD CONSTRAINT fk_maintenance_contact_person FOREIGN KEY (maintenance_contact_person) REFERENCES maintenance(maintenance_contact_person);
  ERROR:  syntax error at or near "ERROR"
  LINE 1: ERROR:  syntax error at or near "c"
          ^
  bikefacility=# ERROR:  column "maintenance_contact_person" referenced in foreign key constraint does not exist
  bikefacility-# bikefacility=# ALTER TABLE bicycle ADD CONSTRAINT fk_rental_period FOREIGN KEY (rental_period) REFERENCES rental(rental_period);
  ERROR:  syntax error at or near "ERROR"
  LINE 1: ERROR:  column "maintenance_contact_person" referenced in fo...
          ^
  bikefacility=# ERROR:  column "rental_period" referenced in foreign key constraint does not exist
  bikefacility-# bikefacility=# ALTER TABLE bicycle ADD CONSTRAINT fk_terminal_id FOREIGN KEY (terminal_id) REFERENCES terminal(terminal_id);
  ERROR:  syntax error at or near "ERROR"
  LINE 1: ERROR:  column "rental_period" referenced in foreign key con...
          ^
  bikefacility=# ERROR:  column "terminal_id" referenced in foreign key constraint does not exist
  
  </code></pre>
  
  <p>This is my code. I've created the same style of foreign keys within the code as you can see here.</p>
  
  <pre><code>CREATE TABLE member (
    member_id INTEGER PRIMARY KEY,
    member_fname VARCHAR(15) NOT NULL,
    member_lname VARCHAR(15) NOT NULL,
    member_status VARCHAR(15) NOT NULL,
    member_address VARCHAR(10) NOT NULL,
    member_email VARCHAR(30) NOT NULL
  );
  
  CREATE TABLE bicycle (
    bicycle_id INTEGER PRIMARY KEY,
    bicycle_brand VARCHAR(25) NOT NULL,
    bicycle_model VARCHAR(25) NOT NULL,
    bicycle_colour VARCHAR(15) NOT NULL,
    bicycle_type VARCHAR(20) NOT NULL,
    bicycle_size VARCHAR(10) NOT NULL,
    bicycle_availability VARCHAR(20) NOT NULL
  
  );
  
  ALTER TABLE bicycle ADD CONSTRAINT fk_bicycle_pickup_date FOREIGN KEY (bicycle_pickup_date) REFERENCES rental(bicycle_pickup_date) &gt;MATCH FULL;
  ALTER TABLE bicycle ADD CONSTRAINT fk_maintenance_contact_person FOREIGN KEY (maintenance_contact_person) REFERENCES maintenance(maintenance_contact_person);
  ALTER TABLE bicycle ADD CONSTRAINT fk_terminal_id FOREIGN KEY (terminal_id) REFERENCES terminal(terminal_id);
  ALTER TABLE bicycle ADD CONSTRAINT fk_rental_period FOREIGN KEY (rental_period) REFERENCES rental(rental_period);
  
  CREATE TABLE sponsor (
    sponsor_id INTEGER PRIMARY KEY,
    sponsor_name VARCHAR(15) NOT NULL,
    sponsor_contact VARCHAR(30) NOT NULL,
    sponsor_period DATE NOT NULL,
    sponsor_address VARCHAR(50) NOT NULL,
    sponsor_fee DECIMAL (6, 2) NOT NULL
  );
  
  CREATE TABLE terminal (
    terminal_id INTEGER PRIMARY KEY,
    terminal_address VARCHAR(50) NOT NULL,
    terminal_minstorage VARCHAR(50) NOT NULL,
    terminal_maxstorage VARCHAR(50) NOT NULL
  );
  
  CREATE TABLE rental (
    rental_no INTEGER PRIMARY KEY,
    rental_period DATE NOT NULL,
    bicycle_pickup_date DATE NOT NULL
  );
  
  
  
  </code></pre>
  
  <p>It says that the columns don't exist but I know they do because they're right there! Can someone help me out, please? Thanks in advance! </p>