Question

Given a Postgresql table schema:

create table thing (
    id serial primary key,
    key text,
    type int references thing,   
    latest_revision int default 1,
    created timestamp default(current_timestamp at time zone 'utc'),
    last_modified timestamp default(current_timestamp at time zone 'utc')
);
$for name in ['key', 'type', 'latest_revision', 'last_modified', 'created']:
    create index thing_${name}_idx ON thing($name);

There are two lines i do not understand and am wondering if it is even possible to convert them to a MySql table schema? Can the following line be converted to something MySql would understand, as it seems to be referencing itself:

type int references thing,

Plus, is there a MySql equivalent for the last line:

$for name in ['key', 'type', 'latest_revision', 'last_modified', 'created']:
    create index thing_${name}_idx ON thing($name);

Answer 1

The references line is a foreign key, you can use something like this in MySQL:

CREATE TABLE thing (
   ...
   type int,
   FOREIGN KEY (type) REFERENCES thing (id),
   ...
);

The last two lines are not in SQL, it’s some scripting language. It simply creates indexes on the mentioned columns:

CREATE INDEX thing_key_idx ON thing (key);
CREATE INDEX thing_type_idx ON thing (type);
...