# Empolyee table
table employees (
    id serial for 'employee number';
    name text /[A-Z][a-z]{2,5} [A-Z][a-z]{2,7}/ not null unique;
    age integer 18..60 not null;
    tel text /1[35]8\d{8}/ for 'telephone number';
    birthday date;
    height real 1.50 .. 1.90 not null;
    grades text {'A','B','C','D','E'} not null for '分数';
    department references departments.id;
)

# Department table
table departments (
    id serial;
    name text /\w{2,10}/ not null;
)

10 employees;
2 departments;