Knex.js is a "batteries included" SQL query builder for Postgres, MSSQL, MySQL, MariaDB, SQLite3, and Oracle designed to be flexible, portable, and fun to use. It features both traditional node style callbacks as well as a promise interface for cleaner async flow control, a stream interface, full featured query and schema builders, transaction support (with savepoints), connection pooling and standardized responses between different query clients and dialects.

The project is hosted on GitHub, and has a comprehensive test suite.

Knex is available for use under the MIT software license.

You can report bugs and discuss features on the GitHub issues page, add pages to the wiki or send tweets to @tgriesser.

Thanks to all of the great contributions to the project.

generic-pool is swapped out for Pool2 for pooling management

Documentation pull requests should be sent to knex/documentation

PG escaping should now be handled the same as it is by the driver

The client created by the configuration initializes a connection pool, using the generic-pool library. This connection pool has a default setting of a min: 2, max: 10 for the MySQL and PG libraries, and a single connection for sqlite3 (due to issues with utilizing multiple connections on a single file). To change the config settings for the pool, pass a pool option as one of the keys in the initialize block.

Checkout the generic-pool library for more information.

The query builder starts off either by specifying a tableName you wish to query against, or by calling any method directly on the knex object. This kicks off a jQuery-like chain, with which you can call additional query builder methods as needed to construct the query, eventually calling any of the interface methods, to either convert toString, or execute the query with a promise, callback, or stream. Optional second argument for passing options: only: if true, the ONLY keyword is used before the tableName to discard inheriting tables' data. *NOTE: only supported in PostgreSQL for now.

Sets a timeout for the query and will throw a TimeoutError if the timeout is exceeded. The error contains information about the query, bindings, and the timeout that was set. Useful for complex queries that you want to make sure are not taking too long to execute. Optional second argument for passing options: cancel: if true, cancel query if timeout is reached. *NOTE: only supported in MySQL and MariaDB for now.

knex.select().from('books').timeout(1000)
Outputs:
select * from `books`

knex.select().from('books').timeout(1000, {cancel: true}) // MySQL and MariaDB only
Outputs:
select * from `books`

Creates a select query, taking an optional array of columns for the query, eventually defaulting to * if none are specified when the query is built. The response of a select call will resolve with an array of objects selected from the database.

knex.select('title', 'author', 'year').from('books')
Outputs:
select `title`, `author`, `year` from `books`

knex.select().table('books')
Outputs:
select * from `books`

Allows for aliasing a subquery, taking the string you wish to name the current query. If the query is not a sub-query, it will be ignored.

knex.avg('sum_column1').from(function() {
  this.sum('column1 as sum_column1').from('t1').groupBy('column1').as('t1')
}).as('ignored_alias')
Outputs:
select avg(`sum_column1`) from (select sum(`column1`) as `sum_column1` from `t1` group by `column1`) as `t1`

Specifically set the columns to be selected on a select query, taking an array or a list of of column names.

knex.column('title', 'author', 'year').select().from('books')
Outputs:
select `title`, `author`, `year` from `books`

knex.column(['title', 'author', 'year']).select().from('books')
Outputs:
select `title`, `author`, `year` from `books`

Specifies the table used in the current query, replacing the current table name if one has already been specified. This is typically used in the sub-queries performed in the advanced where or union methods. Optional second argument for passing options: only: if true, the ONLY keyword is used before the tableName to discard inheriting tables' data. *NOTE: only supported in PostgreSQL for now.

knex.select('*').from('users')
Outputs:
select * from `users`

Add a "with" clause to the query. "With" clauses are supported by PostgreSQL, Oracle, SQLite3 and MSSQL.

knex.with('with_alias', knex.raw('select * from "books" where "author" = ?', 'Test')).select('*').from('with_alias')
Outputs:
with `with_alias` as (select * from "books" where "author" = 'Test') select * from `with_alias`

knex.with('with_alias', (qb) => {
  qb.select('*').from('books').where('author', 'Test')
}).select('*').from('with_alias')
Outputs:
with `with_alias` as (select * from `books` where `author` = 'Test') select * from `with_alias`

Specifies the schema to be used as prefix of table name.

knex.withSchema('public').select('*').from('users')
Outputs:
select * from `public`.`users`

Several methods exist to assist in dynamic where clauses. In many places functions may be used in place of values, constructing subqueries. In most places existing knex queries may be used to compose sub-queries, etc. Take a look at a few of the examples for each method for instruction on use:

Important: Supplying knex with an undefined value to any of the where functions will cause knex to throw an error during sql compilation. This is both for yours and our sake. Knex cannot know what to do with undefined values in a where clause, and generally it would be a programmatic error to supply one to begin with. The error will throw a message containing the type of query and the compiled query-string. Example:

Shorthand for .where('id', 'in', obj), the .whereIn and .orWhereIn methods add a "where in" clause to the query.

knex.select('name').from('users')
.whereIn('id', [1, 2, 3])
.orWhereIn('id', [4, 5, 6])
Outputs:
select `name` from `users` where `id` in (1, 2, 3) or `id` in (4, 5, 6)

knex.select('name').from('users')
.whereIn('account_id', function() {
  this.select('id').from('accounts');
})
Outputs:
select `name` from `users` where `account_id` in (select `id` from `accounts`)

var subquery = knex.select('id').from('accounts');

knex.select('name').from('users')
  .whereIn('account_id', subquery)
Outputs:
select `name` from `users` where `account_id` in (select `id` from `accounts`)

knex('users').whereNotIn('id', [1, 2, 3])
Outputs:
select * from `users` where `id` not in (1, 2, 3)

knex('users').where('name', 'like', '%Test%').orWhereNotIn('id', [1, 2, 3])
Outputs:
select * from `users` where `name` like '%Test%' or `id` not in (1, 2, 3)

knex('users').whereNull('updated_at')
Outputs:
select * from `users` where `updated_at` is null

knex('users').whereNotNull('created_at')
Outputs:
select * from `users` where `created_at` is not null

knex('users').whereExists(function() {
  this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
})
Outputs:
select * from `users` where exists (select * from `accounts` where users.account_id = accounts.id)

knex('users').whereExists(knex.select('*').from('accounts').whereRaw('users.account_id = accounts.id'))
Outputs:
select * from `users` where exists (select * from `accounts` where users.account_id = accounts.id)

knex('users').whereNotExists(function() {
  this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
})
Outputs:
select * from `users` where not exists (select * from `accounts` where users.account_id = accounts.id)

knex('users').whereNotExists(knex.select('*').from('accounts').whereRaw('users.account_id = accounts.id'))
Outputs:
select * from `users` where not exists (select * from `accounts` where users.account_id = accounts.id)

knex('users').whereBetween('votes', [1, 100])
Outputs:
select * from `users` where `votes` between 1 and 100

knex('users').whereNotBetween('votes', [1, 100])
Outputs:
select * from `users` where `votes` not between 1 and 100

Convenience helper for .where(knex.raw(query)).

knex('users').whereRaw('id = ?', [1])
Outputs:
select * from `users` where id = 1

The join builder can be used to specify joins between tables, with the first argument being the joining table, the next three arguments being the first join column, the join operator and the second join column, respectively.

knex('users')
.join('contacts', 'users.id', '=', 'contacts.user_id')
.select('users.id', 'contacts.phone')
Outputs:
select `users`.`id`, `contacts`.`phone` from `users` inner join `contacts` on `users`.`id` = `contacts`.`user_id`

knex('users')
.join('contacts', 'users.id', 'contacts.user_id')
.select('users.id', 'contacts.phone')
Outputs:
select `users`.`id`, `contacts`.`phone` from `users` inner join `contacts` on `users`.`id` = `contacts`.`user_id`

knex.from('users').innerJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` inner join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.table('users').innerJoin('accounts', 'users.id', '=', 'accounts.user_id')
Outputs:
select * from `users` inner join `accounts` on `users`.`id` = `accounts`.`user_id`

knex('users').innerJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` inner join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').leftJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` left join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').leftJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` left join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').leftOuterJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` left outer join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').leftOuterJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` left outer join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').rightJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` right join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').rightJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` right join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').rightOuterJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` right outer join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').rightOuterJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` right outer join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').outerJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` outer join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').outerJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` outer join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').fullOuterJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` full outer join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').fullOuterJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` full outer join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('users').crossJoin('accounts', 'users.id', 'accounts.user_id')
Outputs:
select * from `users` cross join `accounts` on `users`.`id` = `accounts`.`user_id`

knex.select('*').from('users').crossJoin('accounts', function() {
  this.on('accounts.id', '=', 'users.account_id').orOn('accounts.owner_id', '=', 'users.id')
})
Outputs:
select * from `users` cross join `accounts` on `accounts`.`id` = `users`.`account_id` or `accounts`.`owner_id` = `users`.`id`

knex.select('*').from('accounts').joinRaw('natural full join table1').where('id', 1)
Outputs:
select * from `accounts` natural full join table1 where `id` = 1

knex.select('*').from('accounts').join(knex.raw('natural full join table1')).where('id', 1)
Outputs:
select * from `accounts` inner join natural full join table1 where `id` = 1

Adds a onIn clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onIn('contacts.id', [7, 15, 23, 41])
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`id` in (7, 15, 23, 41)

Adds a onNotIn clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onNotIn('contacts.id', [7, 15, 23, 41])
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`id` not in (7, 15, 23, 41)

Adds a onNull clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onNull('contacts.email')
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`email` is null

Adds a onNotNull clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onNotNull('contacts.email')
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`email` is not null

Adds a onExists clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onExists(function() {
    this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
  })
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and exists (select * from `accounts` where users.account_id = accounts.id)

Adds a onNotExists clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onNotExists(function() {
    this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
  })
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and not exists (select * from `accounts` where users.account_id = accounts.id)

Adds a onBetween clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onBetween('contacts.id', [5, 30])
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`id` between 5 and 30

Adds a onNotBetween clause to the query.

knex.select('*').from('users').join('contacts', function() {
  this.on('users.id', '=', 'contacts.id').onNotBetween('contacts.id', [5, 30])
})
Outputs:
select * from `users` inner join `contacts` on `users`.`id` = `contacts`.`id` and `contacts`.`id` not between 5 and 30

Clears all select clauses from the query, excluding subqueries.

knex.select('email', 'name').from('users').clearSelect()
Outputs:
select * from `users`

Clears all where clauses from the query, excluding subqueries.

knex.select('email', 'name').from('users').where('id', 1).clearWhere()
Outputs:
select `email`, `name` from `users`

Sets a distinct clause on the query.

// select distinct 'first_name' from customers
knex('customers')
  .distinct('first_name', 'last_name')
  .select()
Outputs:
select distinct `first_name`, `last_name` from `customers`

Adds a group by clause to the query.

knex('users').groupBy('count')
Outputs:
select * from `users` group by `count`

Adds a raw group by clause to the query.

knex.select('year', knex.raw('SUM(profit)')).from('sales').groupByRaw('year WITH ROLLUP')
Outputs:
select `year`, SUM(profit) from `sales` group by year WITH ROLLUP

Adds an order by clause to the query.

knex('users').orderBy('name', 'desc')
Outputs:
select * from `users` order by `name` desc

Adds an order by raw clause to the query.

knex.select('*').from('table').orderByRaw('col DESC NULLS LAST')
Outputs:
select * from `table` order by col DESC NULLS LAST

Adds a having clause to the query.

knex('users')
.groupBy('count')
.orderBy('name', 'desc')
.having('count', '>', 100)
Outputs:
select * from `users` group by `count` having `count` > 100 order by `name` desc

Adds a havingIn clause to the query.

knex.select('*').from('users').havingIn('id', [5, 3, 10, 17])
Outputs:
select * from `users` having `id` in (5, 3, 10, 17)

Adds a havingNotIn clause to the query.

knex.select('*').from('users').havingNotIn('id', [5, 3, 10, 17])
Outputs:
select * from `users` having `id` not in (5, 3, 10, 17)

Adds a havingNull clause to the query.

knex.select('*').from('users').havingNull('email')
Outputs:
select * from `users` having `email` is null

Adds a havingNotNull clause to the query.

knex.select('*').from('users').havingNotNull('email')
Outputs:
select * from `users` having `email` is not null

Adds a havingExists clause to the query.

knex.select('*').from('users').havingExists(function() {
  this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
})
Outputs:
select * from `users` having exists (select * from `accounts` where users.account_id = accounts.id)

Adds a havingNotExists clause to the query.

knex.select('*').from('users').havingNotExists(function() {
  this.select('*').from('accounts').whereRaw('users.account_id = accounts.id');
})
Outputs:
select * from `users` having not exists (select * from `accounts` where users.account_id = accounts.id)

Adds a havingBetween clause to the query.

knex.select('*').from('users').havingBetween('id', [5, 10])
Outputs:
select * from `users` having `id` between 5 and 10

Adds a havingNotBetween clause to the query.

knex.select('*').from('users').havingNotBetween('id', [5, 10])
Outputs:
select * from `users` having `id` not between 5 and 10

Adds a havingRaw clause to the query.

knex('users')
.groupBy('count')
.orderBy('name', 'desc')
.havingRaw('count > ?', [100])
Outputs:
select * from `users` group by `count` having count > 100 order by `name` desc

Adds an offset clause to the query.

knex.select('*').from('users').offset(10)
Outputs:
select * from `users` limit 18446744073709551615 offset 10

Adds a limit clause to the query.

knex.select('*').from('users').limit(10).offset(30)
Outputs:
select * from `users` limit 10 offset 30

Creates a union query, taking an array or a list of callbacks to build the union statement, with optional boolean wrap. The queries will be individually wrapped in parentheses with a true wrap parameter.

knex.select('*').from('users').whereNull('last_name').union(function() {
  this.select('*').from('users').whereNull('first_name');
})
Outputs:
select * from `users` where `last_name` is null union select * from `users` where `first_name` is null

Creates a union all query, with the same method signature as the union method.

knex.select('*').from('users').whereNull('last_name').unionAll(function() {
  this.select('*').from('users').whereNull('first_name');
})
Outputs:
select * from `users` where `last_name` is null union all select * from `users` where `first_name` is null

Creates an insert query, taking either a hash of properties to be inserted into the row, or an array of inserts, to be executed as a single insert command. Resolves the promise / fulfills the callback with an array containing the first insert id of the inserted model, or an array containing all inserted ids for postgresql.

// Returns [1] in "mysql", "sqlite", "oracle"; [] in "postgresql" unless the 'returning' parameter is set.
knex('books').insert({title: 'Slaughterhouse Five'})
Outputs:
insert into `books` (`title`) values ('Slaughterhouse Five')

// Normalizes for empty keys on multi-row insert:
knex('coords').insert([{x: 20}, {y: 30},  {x: 10, y: 20}])
Outputs:
insert into `coords` (`x`, `y`) values (20, DEFAULT), (DEFAULT, 30), (10, 20)

// Returns [2] in "mysql", "sqlite"; [2, 3] in "postgresql"
knex.insert([{title: 'Great Gatsby'}, {title: 'Fahrenheit 451'}], 'id').into('books')
Outputs:
insert into `books` (`title`) values ('Great Gatsby'), ('Fahrenheit 451')

Utilized by PostgreSQL, MSSQL, and Oracle databases, the returning method specifies which column should be returned by the insert and update methods. Passed column parameter may be a string or an array of strings. When passed in a string, makes the SQL result be reported as an array of values from the specified column. When passed in an array of strings, makes the SQL result be reported as an array of objects, each containing a single property for each of the specified columns.

// Returns [1]
knex('books')
  .returning('id')
  .insert({title: 'Slaughterhouse Five'})
Outputs:
insert into `books` (`title`) values ('Slaughterhouse Five')

// Returns [2] in "mysql", "sqlite"; [2, 3] in "postgresql"
knex('books')
  .returning('id')
  .insert([{title: 'Great Gatsby'}, {title: 'Fahrenheit 451'}])
Outputs:
insert into `books` (`title`) values ('Great Gatsby'), ('Fahrenheit 451')

// Returns [ { id: 1, title: 'Slaughterhouse Five' } ]
knex('books')
  .returning(['id','title'])
  .insert({title: 'Slaughterhouse Five'})
Outputs:
insert into `books` (`title`) values ('Slaughterhouse Five')

Creates an update query, taking a hash of properties or a key/value pair to be updated based on the other query constraints. Resolves the promise / fulfills the callback with the number of affected rows for the query. If a key to be updated has value undefined it is ignored.

knex('books')
.where('published_date', '<', 2000)
.update({
  status: 'archived',
  thisKeyIsSkipped: undefined
})
Outputs:
update `books` set `status` = 'archived' where `published_date` < 2000

// Returns [1] in "mysql", "sqlite", "oracle"; [] in "postgresql" unless the 'returning' parameter is set.
knex('books').update('title', 'Slaughterhouse Five')
Outputs:
update `books` set `title` = 'Slaughterhouse Five'

Aliased to del as delete is a reserved word in JavaScript, this method deletes one or more rows, based on other conditions specified in the query. Resolves the promise / fulfills the callback with the number of affected rows for the query.

knex('accounts')
.where('activated', false)
.del()
Outputs:
delete from `accounts` where `activated` = false

Used by knex.transaction, the transacting method may be chained to any query and passed the object you wish to join the query as part of the transaction for.

var Promise = require('bluebird');
knex.transaction(function(trx) {
  knex('books').transacting(trx).insert({name: 'Old Books'})
    .then(function(resp) {
      var id = resp[0];
      return someExternalMethod(id, trx);
    })
    .then(trx.commit)
    .catch(trx.rollback);
})
.then(function(resp) {
  console.log('Transaction complete.');
})
.catch(function(err) {
  console.error(err);
});

Dynamically added after a transaction is specified, the forUpdate adds a FOR UPDATE in PostgreSQL and MySQL during a select statement.

knex('tableName')
.transacting(trx)
.forUpdate()
.select('*')
Outputs:
select * from `tableName` for update

Dynamically added after a transaction is specified, the forShare adds a FOR SHARE in PostgreSQL and a LOCK IN SHARE MODE for MySQL during a select statement.

knex('tableName')
.transacting(trx)
.forShare()
.select('*')
Outputs:
select * from `tableName` lock in share mode

Performs a count on the specified column. Note that in Postgres, count returns a bigint type which will be a String and not a Number (more info).

knex('users').count('active')
Outputs:
select count(`active`) from `users`

knex('users').count('active as a')
Outputs:
select count(`active`) as `a` from `users`

Gets the minimum value for the specified column.

knex('users').min('age')
Outputs:
select min(`age`) from `users`

knex('users').min('age as a')
Outputs:
select min(`age`) as `a` from `users`

Gets the maximum value for the specified column.

knex('users').max('age')
Outputs:
select max(`age`) from `users`

knex('users').max('age as a')
Outputs:
select max(`age`) as `a` from `users`

Retrieve the sum of the values of a given column.

knex('users').sum('products')
Outputs:
select sum(`products`) from `users`

knex('users').sum('products as p')
Outputs:
select sum(`products`) as `p` from `users`

Retrieve the average of the values of a given column.

knex('users').avg('age')
Outputs:
select avg(`age`) from `users`

knex('users').avg('age as a')
Outputs:
select avg(`age`) as `a` from `users`

Increments a column value by the specified amount.

knex('accounts')
.where('userid', '=', 1)
.increment('balance', 10)
Outputs:
update `accounts` set `balance` = `balance` + 10 where `userid` = 1

Decrements a column value by the specified amount.

knex('accounts').where('userid', '=', 1).decrement('balance', 5)
Outputs:
update `accounts` set `balance` = `balance` - 5 where `userid` = 1

Truncates the current table.

knex('accounts').truncate()
Outputs:
truncate `accounts`

This will pluck the specified column from each row in your results, yielding a promise which resolves to the array of values selected.

knex.table('users').pluck('id').then(function(ids) { console.log(ids); });

Similar to select, but only retrieves & resolves with the first record from the query.

knex.table('users').first('id', 'name').then(function(row) { console.log(row); });

Clones the current query chain, useful for re-using partial query snippets in other queries without mutating the original.

Allows encapsulating and re-using query snippets and common behaviors as functions. The callback function should receive the query builder as its first argument, followed by the rest of the (optional) parameters passed to modify.

var withUserName = function(queryBuilder, foreignKey) {
  queryBuilder.leftJoin('users', foreignKey, 'users.id').select('users.user_name');
};
knex.table('articles').select('title', 'body').modify(withUserName, 'articles_user.id').then(function(article) {
  console.log(article.user_name);
});

Returns an object with the column info about the current table, or an individual column if one is passed, returning an object with the following keys: defaultValue: the default value for the column type: the column type maxLength: the max length set for the column nullable: whether the column may be null

knex('users').columnInfo().then(function(info) { // ... });

Overrides the global debug setting for the current query chain. If enabled is omitted, query debugging will be turned on.

(incomplete) - This feature was incorrectly documented as functional.
If implemented, the method would set the db connection to use for the query without using the connection pool.

Allows for mixing in additional options as defined by database client specific libraries:

knex('accounts as a1')
.leftJoin('accounts as a2', function() {
  this.on('a1.email', '<>', 'a2.email');
})
.select(['a1.email', 'a2.email'])
.where(knex.raw('a1.id = 1'))
.option({ nestTables: true, rowMode: 'array' })
.limit(2)
.then(...

Transactions are an important feature of relational databases, as they allow correct recovery from failures and keep a database consistent even in cases of system failure. All queries within a transaction are executed on the same database connection, and run the entire set of queries as a single unit of work. Any failure will mean the database will rollback any queries executed on that connection to the pre-transaction state.

Transactions are handled by passing a handler function into knex.transaction. The handler function accepts a single argument, an object which may be used in two ways:

1. As the "promise aware" knex connection
2. As an object passed into a query with and eventually call commit or rollback.

Throwing an error directly from the transaction handler function automatically rolls back the transaction, same as returning a rejected promise.

Notice that if a promise is not returned within the handler, it is up to you to ensure trx.commit, or trx.rollback are called, otherwise the transaction connection will hang.

Specifies the schema to be used when using the schema-building commands.

knex.schema.withSchema('public').createTable('users', function (table) {
  table.increments();
})
Outputs:
create table `public`.`users` (`id` int unsigned not null auto_increment primary key)

Creates a new table on the database, with a callback function to modify the table's structure, using the schema-building commands.

knex.schema.createTable('users', function (table) {
  table.increments();
  table.string('name');
  table.timestamps();
})
Outputs:
create table `users` (`id` int unsigned not null auto_increment primary key, `name` varchar(255), `created_at` datetime, `updated_at` datetime)

Creates a new table on the database if it doesn't exists on database, with a callback function to modify the table's structure, using the schema-building commands.

knex.schema.createTableIfNotExists('users', function (table) {
  table.increments();
  table.string('name');
  table.timestamps();
})
Outputs:
create table if not exists `users` (`id` int unsigned not null auto_increment primary key, `name` varchar(255), `created_at` datetime, `updated_at` datetime)

Renames a table from a current tableName to another.

knex.schema.renameTable('users', 'old_users')
Outputs:
rename table `users` to `old_users`

Drops a table, specified by tableName.

knex.schema.dropTable('users')
Outputs:
drop table `users`

Checks for a table's existence by tableName, resolving with a boolean to signal if the table exists.

knex.schema.hasTable('users').then(function(exists) {
  if (!exists) {
    return knex.schema.createTable('users', function(t) {
      t.increments('id').primary();
      t.string('first_name', 100);
      t.string('last_name', 100);
      t.text('bio');
    });
  }
});

Checks if a column exists in the current table, resolves the promise with a boolean, true if the column exists, false otherwise.

Drops a table conditionally if the table exists, specified by tableName.

knex.schema.dropTableIfExists('users')
Outputs:
drop table if exists `users`

Chooses a database table, and then modifies the table, using the Schema Building functions inside of the callback.

knex.schema.table('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
})
Outputs:
alter table `users` add `first_name` varchar(255), add `last_name` varchar(255);
alter table `users` drop `name`

Run an arbitrary sql query in the schema builder chain.

knex.schema.raw("SET sql_mode='TRADITIONAL'")
.table('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
})
Outputs:
SET sql_mode='TRADITIONAL';
alter table `users` add `first_name` varchar(255), add `last_name` varchar(255);
alter table `users` drop `name`

Drops a column, specified by the column's name

Drops multiple columns, taking a variable number of column names.

Renames a column from one name to another.

Adds an auto incrementing column, in PostgreSQL this is a serial. This will be used as the primary key for the table. Also available is a bigIncrements if you wish to add a bigint incrementing number (in PostgreSQL bigserial).

Adds an integer column.

In MySQL or PostgreSQL, adds a bigint column, otherwise adds a normal integer. Note that bigint data is returned as a string in queries because JavaScript may be unable to parse them without loss of precision.

Adds a text column, with optional textType for MySql text datatype preference. textType may be mediumtext or longtext, otherwise defaults to text.

Adds a string column, with optional length defaulting to 255.

Adds a float column, with optional precision (defaults to 8) and scale (defaults to 2).

Adds a decimal column, with optional precision (defaults to 8) and scale (defaults to 2).

Adds a boolean column.

Adds a date column.

Adds a dateTime column.

Adds a time column.

Adds a timestamp column, defaults to timestamptz in PostgreSQL, unless true is passed as the second argument. For Example:

table.timestamp('created_at').defaultTo(knex.fn.now());

Adds a created_at and updated_at column on the database, setting these each to dateTime types. When true is passed as the first argument a timestamp type is used. Both colums default to being not null and the current timestamp when true is passed as the second argument.

Drops the columns created_at and updated_at from the table, which can be created via timestamps.

Adds a binary column, with optional length argument for MySQL.

Adds a enum column, (aliased to enu, as enum is a reserved word in JavaScript). Note that the second argument is an array of values. Example:

table.enu('column', ['value1', 'value2'])

Adds a json column, using the built-in json type in postgresql, defaulting to a text column in older versions of postgresql or in unsupported databases. Note that when setting an array (or a value that could be an array) as the value of a json or jsonb column, you should use JSON.stringify() to convert your value to a string prior to passing it to the query builder, e.g.

knex.table('users')
.where({id: 1})
.update({json_data: JSON.stringify(mightBeAnArray)});

This is because postgresql has a native array type which uses a syntax incompatible with json; knex has no way of knowing which syntax to use, and calling JSON.stringify() forces json-style syntax.

Adds a jsonb column. Works similar to table.json(), but uses native jsonb type if possible.

Adds a uuid column - this uses the built-in uuid type in postgresql, and falling back to a char(36) in other databases.

Sets the comment for a table.

Sets the engine for the database table, only available within a createTable call, and only applicable to MySQL.

Sets the charset for the database table, only available within a createTable call, and only applicable to MySQL.

Sets the collation for the database table, only available within a createTable call, and only applicable to MySQL.

Sets the tables that this table inherits, only available within a createTable call, and only applicable to PostgreSQL.

Sets a specific type for the column creation, if you'd like to add a column type that isn't supported here.

Adds an index to a table over the given columns. A default index name using the columns is used unless indexName is specified. The indexType can be optionally specified for PostgreSQL.

Drops an index from a table. A default index name using the columns is used unless indexName is specified (in which case columns is ignored).

Adds an unique index to a table over the given columns

knex.schema.alterTable('users', function(t) {
  t.unique('email')
})
knex.schema.alterTable('job', function(t) {
  t.unique(['account_id', 'program_id'])
})

Adds a foreign key constraint to a table for an existing column using table.foreign(column).references(column) or multiple columns using table.foreign(columns).references(columns). You can also chain onDelete and/or onUpdate to set the reference option (RESTRICT, CASCADE, SET NULL, NO ACTION) for the operation. Note, this is the same as column.references(column) but works for existing columns.

knex.schema.table('users', function (table) {
  table.integer('user_id').unsigned()
  table.foreign('user_id').references('Items.user_id_in_items')
})

Drops a foreign key constraint from a table. A default foreign key name using the columns is used unless foreignKeyName is specified (in which case columns is ignored).

Drops a unique key constraint from a table. A default unique key name using the columns is used unless indexName is specified (in which case columns is ignored).

Drops the primary key constraint on a table. Defaults to tablename_pkey unless constraintName is specified.

Marks the column as an alter / modify, instead of the default add. Note: This only works in .alterTable() and is not supported by SQlite. Alter is not done incrementally over older column type so if you like to add notNull and keep the old default value, the alter statement must contain both .notNull().defaultTo(1).alter(). If one just tries to add .notNull().alter() the old default value will be dropped.

Specifies a field as an index. If an indexName is specified, it is used in place of the standard index naming convention of tableName_columnName. The indexType can be optionally specified for PostgreSQL. No-op if this is chained off of a field that cannot be indexed.

  When called on a single column it will set that column as the primary key for a table.
  To create a compound primary key, pass an array of column names:
  `table.primary(['column1', 'column2'])`.
  Constraint name defaults to `tablename_pkey` unless `constraintName` is specified.

Sets the column as unique.

Sets the "column" that the current column references as a foreign key. "column" can either be "." syntax, or just the column name followed up with a call to inTable to specify the table.

Sets the "table" where the foreign key column is located after calling column.references.

Sets the SQL command to be run "onDelete".

Sets the SQL command to be run "onUpdate".

Sets the default value for the column on an insert.

Specifies an integer as unsigned. No-op if this is chained off of a non-integer field.

Adds a not null on the current column being created.

Default on column creation, this explicitly sets a field to be nullable.

Sets the column to be inserted on the first position, only used in MySQL alter tables.

Sets the column to be inserted after another, only used in MySQL alter tables.

Sets the comment for a column.

Sets the collation for a column (only works in MySQL). Here is a list of all available collations: https://dev.mysql.com/doc/refman/5.5/en/charset-charsets.html

The batchInsert utility will insert a batch of rows wrapped inside a transaction (which is automatically created unless explicitly given a transaction using transacting), at a given chunkSize.

It's primarily designed to be used when you have thousands of rows to insert into a table.

By default, the chunkSize is set to 1000.

BatchInsert also allows for returning values and supplying transactions using transacting.

Coerces the current query builder chain into a promise state, accepting the resolve and reject handlers as specified by the Promises/A+ spec. As stated in the spec, more than one call to the then method for the current query chain will resolve with the same value, in the order they were called; the query will not be executed multiple times.

knex.select('*')
.from('users')
.where({name: 'Tim'})
.then(function(rows) {
  return knex.insert({user_id: rows[0].id, name: 'Test'}, 'id').into('accounts');
})
.then(function(id) {
  console.log('Inserted Account ' + id);
})
.catch(function(error) { console.error(error); });

Coerces the current query builder into a promise state, catching any error thrown by the query, the same as calling .then(null, onRejected).

return knex.insert({id: 1, name: 'Test'}, 'id')
.into('accounts')
.catch(function(error) {
  console.error(error);
}).then(function() {
  return knex.select('*')
    .from('accounts')
    .where('id', 1);
}).then(function(rows) {
  console.log(rows[0]);
})
.catch(function(error) {
  console.error(error);
});

Executes side effects on the resolved response, ultimately returning a promise that fulfills with the original value. A thrown error or rejected promise will cause the promise to transition into a rejected state.

// Using only .then()
query.then(function(x) {
  doSideEffectsHere(x);
  return x;
});

// Using .tap()
promise.tap(doSideEffectsHere);

A passthrough to Bluebird's map implementation with the result set.

knex.select('name').from('users').limit(10).map(function(row) {
  return row.name;
})
.then(function(names) { console.log(names); })
.catch(function(e) { console.error(e); });

A passthrough to Bluebird's reduce implementation with the result set.

knex.select('name').from('users').limit(10).reduce(function(memo, row) {
  memo.names.push(row.name);
  memo.count++;
  return memo;
}, {count: 0, names: []})
.then(function(obj) { console.log(obj); })
.catch(function(e) { console.error(e); });

A passthrough to Bluebird's bind method which sets the context value (this) for the returned promise.

knex.select('name').from('users')
.limit(10)
.bind(console)
.then(console.log)
.catch(console.error)

Shorthand for calling .then(function() { return value }).

// Without return:
knex.insert(values).into('users')
  .then(function() {
    return {inserted: true};
  });

knex.insert(values).into('users').return({inserted: true});

If you'd prefer a callback interface over promises, the asCallback function accepts a standard node style callback for executing the query chain. Note that as with the then method, subsequent calls to the same query chain will return the same result.

knex.select('name').from('users')
.where('id', '>', 20)
.andWhere('id', '<', 200)
.limit(10)
.offset(x)
.asCallback(function(err, rows) {
  if (err) return console.error(err);
  knex.select('id').from('nicknames')
    .whereIn('nickname', _.pluck(rows, 'name'))
    .asCallback(function(err, rows) {
      if (err) return console.error(err);
      console.log(rows);
    });
});

If called with a callback, the callback is passed the stream and a promise is returned. Otherwise, the readable stream is returned.

// Retrieve the stream:
var stream = knex.select('*').from('users').stream();
stream.pipe(writableStream);

// With options:
var stream = knex.select('*').from('users').stream({highWaterMark: 5});
stream.pipe(writableStream);

// Use as a promise:
var stream = knex.select('*').from('users')
  .where(knex.raw('id = ?', [1]))
  .stream(function(stream) {
    stream.pipe(writableStream);
  })
  .then(function() { // ... })
  .catch(function(e) { console.error(e); });

Pipe a stream for the current query to a writableStream.

var stream = knex.select('*').from('users').pipe(writableStream);

A query event is fired just before a query takes place, providing data about the query, including the connection's __cid property and any other information about the query as described in toSQL. Useful for logging all queries throughout your application.

knex.select('*')
.from('users')
.on('query', function(data) {
  app.log(data);
})
.then(function() {
  // ...
});

A query-error event is fired when an error occurs when running a query, providing the error object and data about the query, including the connection's __cid property and any other information about the query as described in toSQL. Useful for logging all query errors throughout your application.

knex.select(['NonExistentColumn'])
.from('users')
.on('query-error', function(error, obj) {
  app.log(error);
})
.then(function() { // ... })
.catch(function(error) {
  // Same error object as the query-error event provides.
});

A query-response event is fired when a successful query has been run, providing the response of the query and data about the query, including the connection's __cid property and any other information about the query as described in toSQL, and finally the query builder used for the query.

knex.select('*')
.from('users')
.on('query-response', function(response, obj, builder) {
  // ...
})
.then(function(response) {
  // Same response as the emitted event
})
.catch(function(error) { });

Returns an array of query strings filled out with the correct values based on bindings, etc. Useful for debugging.

knex.select('*').from('users').where(knex.raw('id = ?', [1])).toString()
Outputs:
select * from `users` where id = 1

Returns an array of query strings filled out with the correct values based on bindings, etc. Useful for debugging.

knex.select('*').from('users').where(knex.raw('id = ?', [1])).toSQL()

// Ouputs: { bindings: [1], method: 'select', sql: 'select * from "users" where id = ?', options: undefined, }

If no seeds.directory is defined, files are created in ./seeds. Note that the seed directory needs to be a relative path. Absolute paths are not supported (nor is it good practice).

To run seed files, execute:

knex.migrate is the class utilized by the knex migrations cli.

Each method takes an optional config object, which may specify the following properties:

Creates a new migration, with the name of the migration being added.

Runs all migrations that have not yet been run.

Rolls back the latest migration group.

Retrieves and returns the current migration version, as a promise. If there aren't any migrations run yet, returns "none" as the value for the currentVersion.

Creates a new seed file, with the name of the seed file being added.

Runs all seed files for the current environment.

How do I help contribute?
Glad you ask! Pull requests, or feature requests, though not always implemented, are a great way to help make Knex even better than it is now. If you're looking for something specific to help out with, there's a number of unit tests that aren't implemented yet, the library could never have too many of those. If you want to submit a fix or feature, take a look at the Contributing readme in the Github and go ahead and open a ticket.

How do I debug?
Knex is beginning to make use of the debug module internally, so you can set the DEBUG environment variable to knex:* to see all debugging, or select individual namespaces DEBUG=knex:query,knex:tx to constrain a bit.

If you pass {debug: true} as one of the options in your initialize settings, you can see all of the query calls being made. Sometimes you need to dive a bit further into the various calls and see what all is going on behind the scenes. I'd recommend node-inspector, which allows you to debug code with debugger statements like you would in the browser.

At the start of your application code will catch any errors not otherwise caught in the normal promise chain handlers, which is very helpful in debugging.

How do I run the test suite?
The test suite looks for an environment variable called KNEX_TEST for the path to the database configuration. If you run the following command:

replacing with the path to your config file, and the config file is valid, the test suite should run properly.

My tests are failing because slow DB connection and short test timeouts! How to extend test timeouts?
Sometimes, e.g. when running CI on travis, test suite's default timeout of 5 seconds might be too short. In such cases an alternative test timeout value in milliseconds can be specified using the KNEX_TEST_TIMEOUT environment variable.

• Multiple concurrent migration runners blocks instead of throwing error when possible #1962
• Fixed transaction promise mutation issue #1991

• Allow passing version of connected db in configuration file #1993
• Bugfixes on batchInsert and transactions for mysql/maria #1992
• Add fetchAsString optional parameter to oracledb dialect #1998
• fix: escapeObject parameter order for Postgres dialect. #2003