wehub-resource-sync
105 lines
3.5 KiB
Markdown
105 lines
3.5 KiB
Markdown
# Drizzle Seed
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> [!NOTE]
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> `drizzle-seed` can only be used with `drizzle-orm@0.36.4` or higher. Versions lower than this may work at runtime but could have type issues and identity column issues, as this patch was introduced in `drizzle-orm@0.36.4`
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## Documentation
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The full API reference and package overview can be found in our [official documentation](https://orm.drizzle.team/docs/seed-overview)
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## Overview
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`drizzle-seed` is a TypeScript library that helps you generate deterministic, yet realistic,
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fake data to populate your database. By leveraging a seedable pseudorandom number generator (pRNG),
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it ensures that the data you generate is consistent and reproducible across different runs.
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This is especially useful for testing, development, and debugging purposes.
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#### What is Deterministic Data Generation?
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Deterministic data generation means that the same input will always produce the same output.
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In the context of `drizzle-seed`, when you initialize the library with the same seed number,
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it will generate the same sequence of fake data every time. This allows for predictable and repeatable data sets.
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#### Pseudorandom Number Generator (pRNG)
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A pseudorandom number generator is an algorithm that produces a sequence of numbers
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that approximates the properties of random numbers. However, because it's based on an initial value
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called a seed, you can control its randomness. By using the same seed, the pRNG will produce the
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same sequence of numbers, making your data generation process reproducible.
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#### Benefits of Using a pRNG:
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- Consistency: Ensures that your tests run on the same data every time.
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- Debugging: Makes it easier to reproduce and fix bugs by providing a consistent data set.
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- Collaboration: Team members can share seed numbers to work with the same data sets.
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With drizzle-seed, you get the best of both worlds: the ability to generate realistic fake data and the control to reproduce it whenever needed.
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## Getting started
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`npm install drizzle-seed`
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You have to install `drizzle-orm` in order to use `drizzle-seed`.
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`npm install drizzle-orm`
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## Basic Usage
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In this example we will create 10 users with random names and ids
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```ts {12}
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import { pgTable, integer, text } from "drizzle-orm/pg-core";
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import { drizzle } from "drizzle-orm/node-postgres";
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import { seed } from "drizzle-seed";
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const users = pgTable("users", {
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id: integer().primaryKey(),
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name: text().notNull(),
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});
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async function main() {
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const db = drizzle(process.env.DATABASE_URL!);
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await seed(db, { users });
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}
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main();
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```
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## Options
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**`count`**
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By default, the `seed` function will create 10 entities.
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However, if you need more for your tests, you can specify this in the seed options object
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```ts
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await seed(db, schema, { count: 1000 });
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```
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**`seed`**
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If you need a seed to generate a different set of values for all subsequent runs, you can define a different number
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in the `seed` option. Any new number will generate a unique set of values
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```ts
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await seed(db, schema, { seed: 12345 });
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```
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## Reset databases
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With `drizzle-seed`, you can easily reset your database and seed it with new values, for example, in your test suites
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```ts
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// path to a file with schema you want to reset
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import * as schema from "./schema.ts";
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import { reset } from "drizzle-seed";
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async function main() {
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const db = drizzle(process.env.DATABASE_URL!);
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await reset(db, schema);
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}
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main();
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```
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More examples are available in our [official documentation](https://orm.drizzle.team/docs/seed-overview) |