Database alteration
The folder for all alteration files.
Format
The alteration files are named in the format of <version>-<timestamp>-name.js
where <timestamp>
is the unix timestamp of when the alteration was created and name
is the name of the alteration, version
is this npm package's version number.
As for development, the version
is "next" until the package is released.
Note that, you SHOULD NOT change the content of the alteration files after they are created. If you need to change the alteration, you should create a new alteration file with the new content.
Deploy unreleased alterations
To deploy scripts with the next
version, run pnpm alteration deploy next
. This is helpful if you want to test your alteration scripts.
Typing
type AlterationScript = {
up: (connection: DatabaseTransactionConnection) => Promise<void>;
down: (connection: DatabaseTransactionConnection) => Promise<void>;
};
When the alteration script is executed, the up
function is called to alter the database schema.
The down
function is designed for the future downgrade feature.
Example
export const up = async (connection) => {
await connection.query(`
alter table "user"
add column "email" varchar(255) not null;
`);
};
export const down = async (connection) => {
await connection.query(`
alter table "user"
drop column "email";
`);
};