sqlite-tables-handler

SQLite Tables Handler

A simple helper for SQLite tables development that makes fields re-definition a deadly simple operation.

import sqlite3 from 'sqlite3';
import sqliteHandler from 'sqlite-tables-handler';

const db = new sqlite3.Database(':memory:');
const whenTables = sqliteHandler(db, {
  // tables as keys and fields definition
  person: {
    id: 'INTEGER NOT NULL PRIMARY KEY',
    name: 'TEXT NOT NULL DEFAULT "anonymous"',
    age: 'NUMBER',
    // if we forgot something else we can change it later on
    // age: 'NUMBER NOT NULL DEFAULT 0'
  },
  // fields can change during development
  company: {
    id: 'INTEGER NOT NULL PRIMARY KEY',
    name: 'TEXT NOT NULL',
    // if we forget the employee field we can add it later on
    // employee: 'INTEGER NOT NULL'
  }
});

whenTables.then(() => {
  // ready to go
  // ...
  db.close();
});

Too many times, during development, I forget some field, or I decide that the type isn't right, or something else.

With this super basic helper, that's not an issue anymore, as I can change types, add, or remove fields, as I go.

API

• db, an sqlite3.Database instance
• object, an object with tables as keys, and fields as their values

Any more complex table/field operation can be performed a part, but behind the module, a PRAGMA check is performed to be sure current fields are the same specified in the existent table, if any, and an automatic upgrade/migration is performed when that's not the case.

Please note renaming fields is not supported, as it'd be impossible to guess what's a new name value should be taken from, so for these operations, please alter manually the table and then update the literal object definition to use the same name.

About Clusters

If multiple forks try simulatenously to migrate one or more tables from one schema to another, disasters might happen.

To prevent such situation, I suggest the usage of id-promise.

import sqlite3 from 'sqlite3';
import sqliteHandler from 'sqlite-tables-handler';

import idPromise from 'id-promise';

const dbPath = './db.sqlite';
const db = new sqlite3.Database(dbPath);

const whenTables = idPromise(
  'sqlite-tables-handler:' + dbPath,
  (resolve, reject) => {
    sqliteHandler(db, {
      my_table: {
        id: 'INTEGER NOT NULL PRIMARY KEY'
      }
    })
    .then(resolve, reject);
  }
);

whenTables.then(() => {
  console.log('SQLite Ready');
  // ...
});

Using id-promise helper at least to be sure tables are ready will ensure no concurrent migrations should ever happen across forks.

See test/multi.js file as example.