knex

Query Building

Builds a SQL query to select all columns from the 'users' table where the 'id' is 1.

knex.select('*').from('users').where('id', 1)

Schema Building

Creates a new table called 'users' with an auto-incrementing 'id' column, a 'name' column of string type, and timestamp columns for 'created_at' and 'updated_at'.

knex.schema.createTable('users', function(table) { table.increments('id'); table.string('name'); table.timestamps(); })

Transaction Support

Performs a transaction to insert multiple records into the 'books' table. If any part of the transaction fails, all changes are rolled back.

knex.transaction(function(trx) { const books = [{title: 'Canterbury Tales'}, {title: 'Macbeth'}]; return trx.insert(books).into('books'); })

Raw Queries

Executes a raw SQL query, selecting all columns from the 'users' table where the 'id' is 1, with parameter binding.

knex.raw('SELECT * FROM users WHERE id = ?', [1])

Seeding

Defines a seed file that first clears the 'users' table and then inserts new records into it.

exports.seed = function(knex) { return knex('users').del().then(function() { return knex('users').insert([{name: 'Alice'}, {name: 'Bob'}]); }); }

Migrations

Defines a migration file with an 'up' method to create a new 'users' table and a 'down' method to drop the 'users' table.

exports.up = function(knex) { return knex.schema.createTable('users', function(table) { table.increments(); table.string('name'); table.timestamps(); }); }; exports.down = function(knex) { return knex.schema.dropTable('users'); };