better-sqlite3-proxy

Efficiently proxy sqlite tables and access data as typical array of objects. Powered by better-sqlite3🔋

Features

• Type safety support for each table
• auto run sqlite statements, supports:
  • create table (only for key-value proxy)
  • select
  • insert
  • update
  • delete
• auto resolve reference row from foreign key into nested objects like ref-db
• auto convert column values into sqlite3 format
  • convert true/false to 1/0
  • convert Date instance to GMT timestamp
  • support searching null / not null columns
• extra helper functions:
  • toSqliteTimestamp (date): string
  • fromSqliteTimestamp (string_or_date): Date
  • seedRow (table, filter, extra?): number
  • upsert (table, key, date)
  • getId (table, key, value)

Array Operations Mapping

Array Operation	Mapped SQL Operation
array.push(...object)	insert
array[id] = object	insert or update
update(array,id,partial)	update
find(array, filter)	select where filter limit 1
filter(array, filter)	select where filter
count(array, filter)	select count where filter
delete array[id]	delete where id
del(array, filter)	delete where filter
array.length = length	delete where id > length
array.slice(start, end)	select where id >= start and id < end

for-of loop, array.forEach(fn), array.filter(fn) and array.map(fn) are also supported, they will receive proxy-ed rows.

Tips: You can use for-of loop instead of array.forEach(fn) if you may terminate the loop early

Tips: You can use filter(partial) instead of array.filter(fn) if possible for better performance

Tips: You can use update(array,id,partial) instead of Object.assign(row,partial) to update multiple columns in batch

Pro Tips: If you need complex query that can be expressed in sql, use prepared statement will have fastest runtime performance.

Lazy Evaluation

The results from mapped operations are proxy-ed object identified by id. Getting the properties on the object will trigger select on corresponding column, and setting the properties will trigger update on corresponding column.

Usage Example

Remark: @beenotung/better-sqlite3-helper is a fork of better-sqlite3-helper. It updates the dependency on better-sqlite3 to v8+ which includes arm64 prebuilds for macOS.

Proxy Relational Tables (click to expand)

More Examples in schema-proxy.spec.ts

import DB from '@beenotung/better-sqlite3-helper'
import { proxySchema, unProxy, find, filter } from 'better-sqlite3-proxy'

let db = DB({
  path: 'dev.sqlite3',
  migrate: {
    migrations: [
      /* sql */ `
-- Up
create table if not exists user (
  id integer primary key
, username text not null unique
);
-- Down
drop table user;
`,
      /* sql */ `
-- Up
create table if not exists post (
  id integer primary key
, user_id integer not null references user (id)
, content text not null
, created_at timestamp not null default current_timestamp
);
-- Down
drop table post;
`,
    ],
  },
})

type DBProxy = {
  user: User[]
  post: Post[]
}
type User = {
  id?: number
  username: string
}
type Post = {
  id?: number
  user_id: number
  content: string
  created_at?: string
  author?: User
}

let proxy = proxySchema<DBProxy>(db, {
  user: ['id', 'username'], // specify columns explicitly or leave it empty to auto-scan from create-table schema
  post: [
    ['author', { field: 'user_id', table: 'user' }], // link up reference fields
  ],
})

// insert record
proxy.user[1] = { username: 'alice' }
proxy.user.push({ username: 'Bob' })
proxy.post.push({ user_id: 1, content: 'Hello World' })

// select a specific column
console.log(proxy.user[1].username) // 'alice'

// select a specific column from reference table
console.log(proxy.post[1].author?.username) // 'alice'

// select all columns of a record
console.log(unProxy(proxy.post[1])) // { id: 1, user_id: 1, content: 'Hello World', created_at: '2022-04-21 23:30:00'}

// update a specific column
proxy.user[1].username = 'Alice'

// update multiple columns
proxy.post[1] = {
  content: 'Hello SQLite',
  created_at: '2022-04-22 08:30:00',
} as Partial<Post> as Post

// find by columns
console.log(find(proxy.user, { username: 'Alice' })?.id) // 1

// filter by columns
console.log(filter(proxy.post, { user_id: 1 })[0].content) // 'Hello SQLite

// delete record
delete proxy.user[2]
console.log(proxy.user.length) // 1

// truncate table
proxy.post.length = 0
console.log(proxy.post.length) // 0

Proxy Key-Value Records (click to expand)

More Examples in key-value.spec.ts

import DB from '@beenotung/better-sqlite3-helper'
import { proxyKeyValue, find, filter } from 'better-sqlite3-proxy'

export let db = DB({
  path: 'dev.sqlite3',
  migrate: false,
})

type DBProxy = {
  users: {
    id: number
    username: string
  }[]
}

let proxy = proxyKeyValue<DBProxy>(db)

// auto create users table, then insert record
proxy.users[1] = { id: 1, username: 'alice' }
proxy.users.push({ id: 2, username: 'Bob' })

// select from users table
console.log(proxy.users[1]) // { id: 1, username: 'alice' }

// update users table
proxy.users[1] = { id: 1, username: 'Alice' }
console.log(proxy.users[1]) // { id:1, username: 'Alice' }

// find by columns
console.log(find(proxy.users, { username: 'Alice' })?.id) // 1

// filter by columns
console.log(filter(proxy.users, { username: 'Bob' })[0].id) // 2

// delete record
delete proxy.users[2]
console.log(proxy.users.length) // 1

// truncate table
proxy.users.length = 0
console.log(proxy.users.length) // 0

License

This project is licensed with BSD-2-Clause

This is free, libre, and open-source software. It comes down to four essential freedoms [ref]:

• The freedom to run the program as you wish, for any purpose
• The freedom to study how the program works, and change it so it does your computing as you wish
• The freedom to redistribute copies so you can help others
• The freedom to distribute copies of your modified versions to others