Question

Imagine

CREATE TABLE titles (
  bookTitle varchar(80)
);

CREATE TABLE borrowers (
  name varchar(80), --borrower's name
  checkedOut varchar(80)[] references titles(bookTitle) --list of checked out
);

Of course that’s not working, but it (hopefully) gets across to you the human reader what I want: I want borrowers to have in one column an array (since more than one title could be checked out at a time) and I want to be sure that only titles that are in the titles table are possible in the borrower’s list of checked out titles. What is the syntax for this?

Answer 1

Why not introduce a third table and store all the checkedOut for that borrower name in there? Forcing an array into a database field is apples and oranges in my opinion.

CREATE TABLE titles (
  bookTitle varchar(80)
);

CREATE TABLE borrowers (
  name varchar(80) --borrower's name
);

CREATE TABLE checkedout (
  name      varchar(80),
  bookTitle varchar(80)
);