Readme
Tiny migrations "framework" that makes using sqlite in vals a little easier.
Not great yet, so far can only run "up" for migrations you haven't run yet or down for all the ones you have run.
See https://www.val.town/v/saolsen/sqlite_migrations_example for usage.
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import { sqlite } from "https://esm.town/v/std/sqlite";
export type Migration = {
name: string;
up: string;
down: string;
};
export type Migrations = {
name: string;
migrations: Migration[];
};
export async function migrate(migrations) {
console.log("Running Migrations");
await sqlite.execute(`
create table if not exists migrations (
id integer primary key autoincrement,
name text not null,
step integer not null
) strict;
`);
let rs = await sqlite.execute({
sql: "select step from migrations where name = :name",
args: { name: migrations.name },
});
let step: number = 0;
if (rs.rows.length === 0) {
await sqlite.execute({
sql: "insert into migrations(name, step) values (:name, :step)",
args: { name: migrations.name, step: 0 },
});
} else {
step = Number(rs.rows[0][0]);
}
let batch = [];
let i = 0;
for (i = 0; i < migrations.migrations.length; i++) {
let migration = migrations.migrations[i];
let migration_step = Number(i) + 1;
if (migration_step > step) {
batch.push(migration.up);
console.log(" ", migration_step, migration.name);
}
}
batch.push({
sql: `update migrations set step = :step where name = :name`,
args: { name: migrations.name, step: i },
});
await sqlite.batch(batch);
console.log("Done");
}
export async function undo(migrations) {
console.log("Undoing Migrations");
await sqlite.execute(`
create table if not exists migrations (
id integer primary key autoincrement,
name text not null,
step integer not null
) strict;
`);
let rs = await sqlite.execute({
sql: "select step from migrations where name = :name",
args: { name: migrations.name },
});
let step: number = 0;
if (rs.rows.length === 0) {
console.log("No migrations have been run.");
return;
} else {
step = Number(rs.rows[0][0]);
}
if (step > 0) {
let batch = [];
let i: number = step;
for (i = step - 1; i >= 0; i--) {
let migration = migrations.migrations[i];
let migration_step = i + 1;
batch.push(migration.down);
console.log(" ", migration_step, migration.name);
}
batch.push({
sql: `update migrations set step = :step where name = :name`,
args: { name: migrations.name, step: i },
});
await sqlite.batch(batch);
}
console.log("Done");
}
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