ContextQMD
Back to Knex

Schema Builder

docs/src/guide/schema-builder.md

016.544.8 KB
Original Source

Schema Builder

The knex.schema is a getter function, which returns a stateful object containing the query. Therefore be sure to obtain a new instance of the knex.schema for every query. These methods return promises.

Dialect badges: [-SQ] = not supported by SQLite. [~SQ] = emulated in SQLite (multiple statements/workarounds).

Essentials

withSchema

knex.schema.withSchema([schemaName])

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

js
// @sql
knex.schema.withSchema('public').createTable('users', function (table) {
  table.increments();
});

createTable

knex.schema.createTable(tableName, callback)

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

js
// @sql
knex.schema.createTable('users', function (table) {
  table.increments();
  table.string('name');
  table.timestamps();
});

createTableLike

knex.schema.createTableLike(tableName, tableNameToCopy, [callback])

Creates a new table on the database based on another table. Copy only the structure : columns, keys and indexes (expected on SQL Server which only copy columns) and not the data. Callback function can be specified to add columns in the duplicated table.

js
// @sql
knex.schema.createTableLike('new_users', 'users');

// "new_users" table contains columns
// of users and two new columns 'age' and 'last_name'.
// @sql
knex.schema.createTableLike('new_users', 'users', (table) => {
  table.integer('age');
  table.string('last_name');
});

dropTable

knex.schema.dropTable(tableName)

Drops a table, specified by tableName.

js
// @sql
knex.schema.dropTable('users');

dropTableIfExists

knex.schema.dropTableIfExists(tableName)

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

js
// @sql
knex.schema.dropTableIfExists('users');

renameTable

knex.schema.renameTable(from, to)

Renames a table from a current tableName to another.

js
// @sql
knex.schema.renameTable('old_users', 'users');

hasTable

knex.schema.hasTable(tableName)

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

js
// @sql
knex.schema.hasTable('users');

hasColumn

knex.schema.hasColumn(tableName, columnName)

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

js
// @sql
knex.schema.hasColumn('users', 'email');

table

knex.schema.table(tableName, callback)

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

js
// @sql
knex.schema.table('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
});

alterTable

knex.schema.alterTable(tableName, callback)

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

js
// @sql
knex.schema.alterTable('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
});

createView

knex.schema.createView(tableName, callback)

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

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.columns(['first_name']);
  view.as(knex('users').select('first_name').where('age', '>', '18'));
});

createViewOrReplace [~SQ]

knex.schema.createViewOrReplace(tableName, callback)

Creates a new view or replace it on the database, with a callback function to modify the view's structure, using the schema-building commands. You need to specify at least the same columns in same order (you can add extra columns). In SQLite, this function generate drop/create view queries (view columns can be different).

js
// @sql
knex.schema.createViewOrReplace('users_view', function (view) {
  view.columns(['first_name']);
  view.as(knex('users').select('first_name').where('age', '>', '18'));
});

createMaterializedView [-MY -SQ -MS]

knex.schema.createMaterializedView(viewName, callback)

Creates a new materialized view on the database, with a callback function to modify the view's structure, using the schema-building commands. Only on PostgreSQL, CockroachDb, Redshift and Oracle.

js
// @sql
knex.schema.createMaterializedView('users_view', function (view) {
  view.columns(['first_name']);
  view.as(knex('users').select('first_name').where('age', '>', '18'));
});

refreshMaterializedView [-MY -SQ -MS]

knex.schema.refreshMaterializedView(viewName)

Refresh materialized view on the database. Only on PostgreSQL, CockroachDb, Redshift and Oracle.

js
// @sql
knex.schema.refreshMaterializedView('users_view');

dropView

knex.schema.dropView(viewName)

Drop view on the database.

js
// @sql
knex.schema.dropView('users_view');

dropViewIfExists

knex.schema.dropViewIfExists(viewName)

Drop view on the database if exists.

js
// @sql
knex.schema.dropViewIfExists('users_view');

dropMaterializedView [-MY -SQ -MS]

knex.schema.dropMaterializedView(viewName)

Drop materialized view on the database. Only on PostgreSQL, CockroachDb, Redshift and Oracle.

js
// @sql
knex.schema.dropMaterializedView('users_view');

dropMaterializedViewIfExists [-MY -SQ -MS]

knex.schema.dropMaterializedViewIfExists(viewName)

Drop materialized view on the database if exists. Only on PostgreSQL, CockroachDb, Redshift and Oracle.

js
// @sql
knex.schema.dropMaterializedViewIfExists('users_view');

renameView [-OR -SQ]

knex.schema.renameView(viewName)

Rename a existing view in the database. Not supported by Oracle and SQLite.

js
// @sql
knex.schema.renameView('users_view');

alterView [-MY -SQ -OR -CR]

knex.schema.alterView(viewName)

Alter view to rename columns or change default values. Only available on PostgreSQL, MSSQL and Redshift.

js
// @sql
knex.schema.alterView('view_test', function (view) {
  view.column('first_name').rename('name_user');
  view.column('bio').defaultTo('empty');
});

generateDdlCommands

knex.schema.generateDdlCommands()

Generates complete SQL commands for applying described schema changes, without executing anything. Useful when knex is being used purely as a query builder. Generally produces same result as .toSQL(), with a notable exception with SQLite, which relies on asynchronous calls to the database for building part of its schema modification statements

js
// @sql
const ddlCommands = knex.schema
  .alterTable('users', (table) => {
    table
      .foreign('companyId')
      .references('company.companyId')
      .withKeyName('fk_fkey_company');
  })
  .generateDdlCommands();

raw

knex.schema.raw(statement)

Run an arbitrary sql query in the schema builder chain.

js
// @sql
knex.schema.raw("SET sql_mode='TRADITIONAL'").table('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
});

queryContext

knex.schema.queryContext(context)

Allows configuring a context to be passed to the wrapIdentifier hook. The context can be any kind of value and will be passed to wrapIdentifier without modification.

js
// @sql
knex.schema.queryContext({ foo: 'bar' }).table('users', function (table) {
  table.string('first_name');
  table.string('last_name');
});

The context configured will be passed to wrapIdentifier for each identifier that needs to be formatted, including the table and column names. However, a different context can be set for the column names via table.queryContext.

Calling queryContext with no arguments will return any context configured for the schema builder instance.

createSchema [-MY -SQ -MS -OR -CR -RS]

knex.schema.createSchema(schemaName)

Creates a new schema. Only supported by PostgreSQL.

js
//create schema 'public'
knex.schema.createSchema('public');

createSchemaIfNotExists [-MY -SQ -MS -OR -CR -RS]

knex.schema.createSchemaIfNotExists(schemaName)

Creates a new schema conditionally if the schema doesnt exist. Only supported by PostgreSQL.

js
//create schema 'public'
knex.schema.createSchemaIfNotExists('public');

dropSchema [-MY -SQ -MS -OR -CR -RS]

knex.schema.dropSchema(schemaName, [cascade])

Drop a schema, specified by the schema's name, with optional cascade option (default to false). Only supported by PostgreSQL.

js
// @sql
//drop schema 'public'
knex.schema.dropSchema('public');
// @sql
//drop schema 'public' cascade
knex.schema.dropSchema('public', true);

dropSchemaIfExists [-MY -SQ -MS -OR -CR -RS]

knex.schema.dropSchemaIfExists(schemaName, [cascade])

Drop a schema conditionally if the schema exists, specified by the schema's name, with optional cascade option (default to false). Only supported by PostgreSQL.

js
// @sql
//drop schema if exists 'public'
knex.schema.dropSchemaIfExists('public');
// @sql
//drop schema if exists 'public' cascade
knex.schema.dropSchemaIfExists('public', true);

Schema Building

dropColumn [~SQ]

table.dropColumn(name)

Drops a column, specified by the column's name

js
// @sql
knex.schema.table('users', function (table) {
  table.dropColumn('name');
});

dropColumns [~SQ]

table.dropColumns(columns)

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

js
// @sql
knex.schema.table('users', function (table) {
  table.dropColumns('first_name', 'last_name');
});

renameColumn

table.renameColumn(from, to)

Renames a column from one name to another.

js
// @sql
knex.schema.table('users', function (table) {
  table.renameColumn('name', 'username');
});

increments

table.increments(name, options={[primaryKey: boolean = true])

Adds an auto incrementing column. In PostgreSQL this is a serial; in Amazon Redshift an integer identity(1,1). This will be used as the primary key for the table if the column isn't in another primary key. Also available is a bigIncrements if you wish to add a bigint incrementing number (in PostgreSQL bigserial). Note that a primary key is created by default if the column isn't in primary key (with primary function), but you can override this behaviour by passing the primaryKey option. If you use this function with primary function, the column is added to the composite primary key. With SQLite, autoincrement column need to be a primary key, so if primary function is used, primary keys are transformed in unique index. MySQL don't support autoincrement column without primary key, so multiple queries are generated to create int column, add increments column to composite primary key then modify the column to autoincrement column.

js
// @sql
// create table 'users'
// with a primary key using 'increments()'
knex.schema.createTable('users', function (table) {
  table.increments('userId');
  table.string('name');
});

// create table 'users'
// with a composite primary key ('userId', 'name').
// increments doesn't generate primary key.
// @sql
knex.schema.createTable('users', function (table) {
  table.primary(['userId', 'name']);
  table.increments('userId');
  table.string('name');
});

// reference the 'users' primary key in new table 'posts'
// @sql
knex.schema.createTable('posts', function (table) {
  table.integer('author').unsigned().notNullable();
  table.string('title', 30);
  table.string('content');

  table.foreign('author').references('userId').inTable('users');
});

A primaryKey option may be passed, to disable to automatic primary key creation:

js
// @sql
// create table 'users'
// with a primary key using 'increments()'
// but also increments field 'other_id'
// that does not need primary key
knex.schema.createTable('users', function (table) {
  table.increments('id');
  table.increments('other_id', { primaryKey: false });
});

integer

table.integer(name, length)

Adds an integer column. On PostgreSQL you cannot adjust the length, you need to use other option such as bigInteger, etc

js
// @sql
knex.schema.createTable('integer_example', function (table) {
  table.integer('age');
});

bigInteger

table.bigInteger(name)

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.

js
// @sql
knex.schema.createTable('big_integer_example', function (table) {
  table.bigInteger('total');
});

tinyint

table.tinyint(name, length)

Adds a tinyint column

js
// @sql
knex.schema.createTable('tinyint_example', function (table) {
  table.tinyint('flag');
});

smallint

table.smallint(name)

Adds a smallint column

js
// @sql
knex.schema.createTable('smallint_example', function (table) {
  table.smallint('rank');
});

mediumint

table.mediumint(name)

Adds a mediumint column

js
// @sql
knex.schema.createTable('mediumint_example', function (table) {
  table.mediumint('counter');
});

bigint

table.bigint(name)

Adds a bigint column

js
// @sql
knex.schema.createTable('bigint_example', function (table) {
  table.bigint('counter');
});

text

table.text(name, [textType])

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

js
// @sql
knex.schema.createTable('text_example', function (table) {
  table.text('bio');
});

string

table.string(name, [length])

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

js
// @sql
knex.schema.createTable('string_example', function (table) {
  table.string('name', 100);
});

float

table.float(column, [precision], [scale])

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

js
// @sql
knex.schema.createTable('float_example', function (table) {
  table.float('rating', 5, 2);
});

double

table.double(column, [precision], [scale])

Adds a double column, with optional precision (defaults to 8) and scale (defaults to 2). In SQLite/MSSQL this is a float with no precision/scale; In PostgreSQL this is a double precision; In Oracle this is a number with matching precision/scale.

js
// @sql
knex.schema.createTable('double_example', function (table) {
  table.double('score', 8, 2);
});

decimal

table.decimal(column, [precision], [scale])

Adds a decimal column, with optional precision (defaults to 8) and scale (defaults to 2). Specifying NULL as precision creates a decimal column that can store numbers of any precision and scale. (Only supported for Oracle, SQLite, Postgres)

js
// @sql
knex.schema.createTable('decimal_example', function (table) {
  table.decimal('amount', 8, 2);
});

boolean

table.boolean(name)

Adds a boolean column.

js
// @sql
knex.schema.createTable('boolean_example', function (table) {
  table.boolean('is_active');
});

date

table.date(name)

Adds a date column.

js
// @sql
knex.schema.createTable('date_example', function (table) {
  table.date('birthdate');
});

datetime

table.datetime(name, options={[useTz: boolean], [precision: number]})

Adds a datetime column. By default PostgreSQL creates column with timezone (timestamptz type). This behaviour can be overriden by passing the useTz option (which is by default true for PostgreSQL). MySQL and MSSQL do not have useTz option.

A precision option may be passed:

js
// @sql
knex.schema.createTable('events', (table) => {
  table.datetime('some_time', { precision: 6 }).defaultTo(knex.fn.now(6));
});

time [-RS]

table.time(name, [precision])

Adds a time column, with optional precision for MySQL. Not supported on Amazon Redshift.

In MySQL a precision option may be passed:

js
// @sql
knex.schema.createTable('events', (table) => {
  table.time('some_time', { precision: 6 });
});

timestamp

table.timestamp(name, options={[useTz: boolean], [precision: number]})

Adds a timestamp column. By default PostgreSQL creates column with timezone (timestamptz type) and MSSQL does not (datetime2). This behaviour can be overriden by passing the useTz option (which is by default false for MSSQL and true for PostgreSQL). MySQL does not have useTz option.

js
// @sql
knex.schema.createTable('events', (table) => {
  table.timestamp('created_at').defaultTo(knex.fn.now());
});

In PostgreSQL and MySQL a precision option may be passed:

js
// @sql
knex.schema.createTable('events', (table) => {
  table.timestamp('created_at', { precision: 6 }).defaultTo(knex.fn.now(6));
});

In PostgreSQL and MSSQL a timezone option may be passed:

js
// @sql
knex.schema.createTable('events', (table) => {
  table.timestamp('created_at', { useTz: true });
});

timestamps

table.timestamps([useTimestamps], [defaultToNow], [useCamelCase])

Adds created_at and updated_at columns on the database, setting each to datetime types. When true is passed as the first argument a timestamp type is used instead. Both columns default to being not null and using the current timestamp when true is passed as the second argument. Note that on MySQL the .timestamps() only have seconds precision, to get better precision use the .datetime or .timestamp methods directly with precision. If useCamelCase is true, the name of columns are createdAt and updatedAt.

::: info PostgreSQL updated_at field will not automatically be updated. Please see this issue for details :::

js
// @sql
knex.schema.createTable('timestamps_example', function (table) {
  table.timestamps(true, true);
});

dropTimestamps

table.dropTimestamps([useCamelCase])

Drops the columns created_at and updated_at from the table, which can be created via timestamps. If useCamelCase is true, the name of columns are createdAt and updatedAt.

js
// @sql
knex.schema.table('timestamps_example', function (table) {
  table.dropTimestamps();
});

binary

table.binary(name, [length])

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

js
// @sql
knex.schema.createTable('binary_example', function (table) {
  table.binary('payload');
});

enum / enu

table.enu(col, values, [options])

Adds a enum column, (aliased to enu, as enum is a reserved word in JavaScript). Implemented as unchecked varchar(255) on Amazon Redshift. Note that the second argument is an array of values. Example:

js
// @sql
knex.schema.createTable('users', (table) => {
  table.enu('column', ['value1', 'value2']);
});

For Postgres, an additional options argument can be provided to specify whether or not to use Postgres's native TYPE:

js
// @sql
knex.schema.createTable('users', (table) => {
  table.enu('column', ['value1', 'value2'], {
    useNative: true,
    enumName: 'foo_type',
  });
});

It will use the values provided to generate the appropriate TYPE. Example:

sql
CREATE TYPE "foo_type" AS ENUM ('value1', 'value2');

To use an existing native type across columns, specify 'existingType' in the options (this assumes the type has already been created):

::: info Since the enum values aren't utilized for a native && existing type, the type being passed in for values is immaterial. :::

js
// @sql
knex.schema.createTable('users', (table) => {
  table.enu('column', ['value1'], {
    useNative: true,
    existingType: true,
    enumName: 'foo_type',
  });
});

If you want to use existing enums from a schema, different from the schema of your current table, specify 'schemaName' in the options:

js
// @sql
knex.schema.createTable('users', (table) => {
  table.enu('column', ['value1'], {
    useNative: true,
    existingType: true,
    enumName: 'foo_type',
    schemaName: 'public',
  });
});

Knex does not provide any way to alter enumerations after creation. To change an enumeration later on you must use Knex.raw, and the appropriate command for your database.

json

table.json(name)

Adds a json column, using the built-in json type in PostgreSQL, MySQL and SQLite, defaulting to a text column in older versions or in unsupported databases.

For PostgreSQL, due to incompatibility between native array and json types, 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.

js
// @sql
knex
  .table('users')
  .where({ id: 1 })
  .update({ json_data: JSON.stringify(['a', 'b']) });

jsonb

table.jsonb(name)

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

js
// @sql
knex.schema.createTable('jsonb_example', function (table) {
  table.jsonb('metadata');
});

uuid [-RS]

table.uuid(name, options=({[useBinaryUuid:boolean],[primaryKey:boolean]})

Adds a uuid column - this uses the built-in uuid type in PostgreSQL, and falling back to a char(36) in other databases by default. If useBinaryUuid is true, binary(16) is used. See uuidToBin function to convert uuid in binary before inserting and binToUuid to convert binary uuid to uuid. If primaryKey is true, then for PostgreSQL the field will be configured as uuid primary key, for CockroackDB an additional default gen_random_uuid() is set on the type.

You may set the default value to the uuid helper function. Not supported by Redshift.

js
// @sql
knex.schema.createTable('uuid_table', (table) => {
  table.uuid('uuidColumn').defaultTo(knex.fn.uuid());
});

geometry [-MY -OR -CR -RS]

table.geometry(name)

Adds a geometry column. Supported by SQLite, MSSQL and PostgreSQL.

js
// @sql
knex.schema.createTable('geo_table', (table) => {
  table.geometry('geometryColumn');
});

geography [-MY -OR -CR -RS]

table.geography(name)

Adds a geography column. Supported by SQLite, MSSQL and PostgreSQL (in PostGIS extension).

js
// @sql
knex.schema.createTable('geo_table', (table) => {
  table.geography('geographyColumn');
});

point [-CR -MS]

table.point(name)

Add a point column. Not supported by CockroachDB and MSSQL.

js
// @sql
knex.schema.createTable('point_table', (table) => {
  table.point('pointColumn');
});

comment

table.comment(value)

Sets the comment for a table.

js
// @sql
knex.schema.createTable('comment_example', function (table) {
  table.increments('id');
  table.comment('Stores example rows');
});

engine [-PG -SQ -MS -OR -CR -RS]

table.engine(val)

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

js
// @sql
knex.schema.createTable('engine_example', function (table) {
  table.increments('id');
  table.engine('InnoDB');
});

charset [-PG -SQ -MS -OR -CR -RS]

table.charset(val)

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

js
// @sql
knex.schema.createTable('charset_example', function (table) {
  table.increments('id');
  table.charset('utf8mb4');
});

collate [-PG -SQ -MS -OR -CR -RS]

table.collate(val)

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

js
// @sql
knex.schema.createTable('collate_example', function (table) {
  table.increments('id');
  table.collate('utf8mb4_unicode_ci');
});

inherits [-MY -SQ -MS -OR -CR -RS]

table.inherits(val)

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

js
// @sql
knex.schema.createTable('inherits_example', function (table) {
  table.increments('id');
  table.inherits('parent_table');
});

specificType

table.specificType(name, type)

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

js
// @sql
knex.schema.createTable('specific_type_example', function (table) {
  table.specificType('ip_address', 'inet');
});

index [-RS]

table.index(columns, [indexName], options=({[indexType: string], [storageEngineIndexType: 'btree'|'hash'], [predicate: QueryBuilder]}))

Adds an index to a table over the given columns. A default index name using the columns is used unless indexName is specified. In MySQL, the storage engine index type may be 'btree' or 'hash' index types, more info in Index Options section : https://dev.mysql.com/doc/refman/8.0/en/create-index.html. The indexType can be optionally specified for PostgreSQL and MySQL. Amazon Redshift does not allow creating an index. In PostgreSQL, SQLite and MSSQL a partial index can be specified by setting a 'where' predicate.

js
// @sql
knex.schema.table('users', function (table) {
  table.index(['name', 'last_name'], 'idx_name_last_name', {
    indexType: 'FULLTEXT',
    storageEngineIndexType: 'hash',
    predicate: knex.whereNotNull('email'),
  });
});

dropIndex [-RS]

table.dropIndex(columns, [indexName])

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). Amazon Redshift does not allow creating an index.

js
// @sql
knex.schema.table('users', function (table) {
  table.dropIndex(['name', 'last_name']);
});

setNullable [~SQ]

table.setNullable(column)

Makes table column nullable.

js
// @sql
knex.schema.table('users', function (table) {
  table.setNullable('email');
});

dropNullable [~SQ]

table.dropNullable(column)

Makes table column not nullable. Note that this operation will fail if there are already null values in this column.

js
// @sql
knex.schema.table('users', function (table) {
  table.dropNullable('email');
});

primary [~SQ]

table.primary(columns, options=({[constraintName:string],[deferrable:'not deferrable'|'deferred'|'immediate']})

Create a primary key constraint on table using input columns. If you need to create a composite primary key, pass an array of columns to columns. Constraint name defaults to tablename_pkey unless constraintName is specified. On Amazon Redshift, all columns included in a primary key must be not nullable. Deferrable primary constraint are supported on Postgres and Oracle and can be set by passing deferrable option to options object.

js
// @sql
knex.schema.createTable('job', function (t) {
  t.string('email');
  t.primary('email', {
    constraintName: 'users_primary_key',
    deferrable: 'deferred',
  });
});

::: info If you want to chain primary() while creating new column you can use primary :::

unique

table.unique(columns, options={[indexName: string], [deferrable:'not deferrable'|'immediate'|'deferred'], [storageEngineIndexType:'btree'|'hash'], [useConstraint:true|false], [predicate: QueryBuilder]})

Adds an unique index to a table over the given columns. In MySQL, the storage engine index type may be 'btree' or 'hash' index types, more info in Index Options section : https://dev.mysql.com/doc/refman/8.0/en/create-index.html. A default index name using the columns is used unless indexName is specified. If you need to create a composite index, pass an array of column to columns. Deferrable unique constraint are supported on Postgres and Oracle and can be set by passing deferrable option to options object. In MSSQL and Postgres, you can set the useConstraint option to true to create a unique constraint instead of a unique index (defaults to false for MSSQL, true for Postgres without predicate, false for Postgres with predicate). In PostgreSQL, SQLite and MSSQL a partial unique index can be specified by setting a 'where' predicate.

js
// @sql
knex.schema.alterTable('users', function (t) {
  t.unique('email');
});
// @sql
knex.schema.alterTable('job', function (t) {
  t.unique(['account_id', 'program_id'], {
    indexName: 'job_composite_index',
    deferrable: 'deferred',
    storageEngineIndexType: 'hash',
  });
});
// @sql
knex.schema.alterTable('job', function (t) {
  t.unique(['account_id', 'program_id'], {
    indexName: 'job_composite_index',
    useConstraint: true,
  });
});
// @sql
knex.schema.alterTable('job', function (t) {
  t.unique(['account_id', 'program_id'], {
    indexName: 'job_composite_index',
    predicate: knex.whereNotNull('account_id'),
  });
});

::: info If you want to chain unique() while creating new column you can use unique :::

foreign [~SQ]

table.foreign(columns, [foreignKeyName])[.onDelete(statement).onUpdate(statement).withKeyName(foreignKeyName).deferrable(type)]

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).inTable(table).

A default key name using the columns is used unless foreignKeyName is specified.

You can also chain onDelete() and/or onUpdate() to set the reference option (RESTRICT, CASCADE, SET NULL, NO ACTION) for the operation. You can also chain withKeyName() to override default key name that is generated from table and column names (result is identical to specifying second parameter to function foreign()).

Deferrable foreign constraints are supported on Postgres, Oracle, and SQLite; calling .deferrable(type) will throw on MySQL, MSSQL, and Redshift.

Note that using foreign() is the same as column.references(column) but it works for existing columns.

js
// @sql
knex.schema.table('users', function (table) {
  table.integer('user_id').unsigned();
  table.foreign('user_id').references('Items.user_id_in_items');
});

Deferrable example:

js
// @sql
knex.schema.table('users', function (table) {
  table
    .foreign('user_id')
    .references('Items.user_id_in_items')
    .deferrable('deferred');
});

dropForeign [~SQ]

table.dropForeign(columns, [foreignKeyName])

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).

js
// @sql
knex.schema.table('users', function (table) {
  table.dropForeign('companyId');
});

dropForeignIfExists

table.dropForeignIfExists(columns, [foreignKeyName])

Like dropForeign, but does not error if the constraint does not exist. Supported on PostgreSQL and other Postgres-based dialects that accept DROP CONSTRAINT IF EXISTS (including CockroachDB). For Redshift, MySQL, MSSQL, Oracle, and SQLite (including better-sqlite3) this method throws “not supported” because those engines do not provide an IF EXISTS form.

js
// @sql
knex.schema.table('users', function (table) {
  table.dropForeignIfExists('companyId');
});

dropUnique

table.dropUnique(columns, [indexName])

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).

js
// @sql
knex.schema.table('job', function (table) {
  table.dropUnique(['account_id', 'program_id'], 'job_composite_index');
});

dropUniqueIfExists

table.dropUniqueIfExists(columns, [indexName])

Like dropUnique, but does not error if the constraint does not exist. Supported in PostgreSQL, CockroachDB, MariaDB, MSSQL, and SQLite/better-sqlite3. Not supported in MySQL, Oracle, or Redshift; calling it there throws a “not supported” error.

js
// @sql
knex.schema.table('job', function (table) {
  table.dropUniqueIfExists(['account_id', 'program_id'], 'job_composite_index');
});

dropPrimary [~SQ]

table.dropPrimary([constraintName])

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

js
// @sql
knex.schema.table('users', function (table) {
  table.dropPrimary();
});

dropPrimaryIfExists

table.dropPrimaryIfExists([constraintName])

Like dropPrimary, but does not error if the constraint does not exist. Supported on PostgreSQL and other Postgres-based dialects that accept DROP CONSTRAINT IF EXISTS (including CockroachDB). Not supported in Redshift, MySQL, MSSQL, Oracle, or SQLite (including better-sqlite3); calling it there throws a “not supported” error.

js
// @sql
knex.schema.table('users', function (table) {
  table.dropPrimaryIfExists();
});

queryContext

table.queryContext(context)

Allows configuring a context to be passed to the wrapIdentifier hook for formatting table builder identifiers. The context can be any kind of value and will be passed to wrapIdentifier without modification.

js
// @sql
knex.schema.table('users', function (table) {
  table.queryContext({ foo: 'bar' });
  table.string('first_name');
  table.string('last_name');
});

This method also enables overwriting the context configured for a schema builder instance via schema.queryContext:

js
// @sql
knex.schema.queryContext('schema context').table('users', function (table) {
  table.queryContext('table context');
  table.string('first_name');
  table.string('last_name');
});

Note that it's also possible to overwrite the table builder context for any column in the table definition:

js
// @sql
knex.schema.queryContext('schema context').table('users', function (table) {
  table.queryContext('table context');
  table.string('first_name').queryContext('first_name context');
  table.string('last_name').queryContext('last_name context');
});

Calling queryContext with no arguments will return any context configured for the table builder instance.

Chainable Methods

The following three methods may be chained on the schema building methods, as modifiers to the column.

alter [~SQ -RS]

column.alter(options={[alterNullable: boolean = true, alterType: boolean = true])

Marks the column as an alter / modify, instead of the default add.

::: warning This only works in .alterTable(). SQLite emulates this by rebuilding the table, and Amazon Redshift does not support it. Alter is not done incrementally over older column type so if you like to add notNullable and keep the old default value, the alter statement must contain both .notNullable().defaultTo(1).alter(). If one just tries to add .notNullable().alter() the old default value will be dropped. Nullable alterations are done only if alterNullable is true. Type alterations are done only if alterType is true. :::

js
// @sql
knex.schema.alterTable('user', function (t) {
  t.increments().primary(); // add
  // drops previous default value from column,
  // change type to string and add not nullable constraint
  t.string('username', 35).notNullable().alter();
  // drops both not null constraint and the default value
  t.integer('age').alter();
  // if alterNullable is false, drops only the default value
  t.integer('age').alter({ alterNullable: false });
  // if alterType is false, type of column is not altered.
  t.integer('age').alter({ alterType: false });
});

index

column.index([indexName], options=({[indexType: string], [storageEngineIndexType: 'btree'|'hash'], [predicate: QueryBuilder]}))

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. In MySQL, the storage engine index type may be 'btree' or 'hash' index types, more info in Index Options section : https://dev.mysql.com/doc/refman/8.0/en/create-index.html. The indexType can be optionally specified for PostgreSQL and MySQL. No-op if this is chained off of a field that cannot be indexed. In PostgreSQL, SQLite and MSSQL a partial index can be specified by setting a 'where' predicate.

js
// @sql
knex.schema.createTable('index_example', function (table) {
  table.string('email').index('idx_email');
});

primary

column.primary(options=({[constraintName:string],[deferrable:'not deferrable'|'deferred'|'immediate']}));

Sets a primary key constraint on column. Constraint name defaults to tablename_pkey unless constraintName is specified. On Amazon Redshift, all columns included in a primary key must be not nullable. Deferrable primary constraint are supported on Postgres and Oracle and can be set by passing deferrable option to options object.

js
// @sql
knex.schema.createTable('users_primary', function (table) {
  table.integer('user_id').primary({
    constraintName: 'users_primary_key',
    deferrable: 'deferred',
  });
});

::: info If you want to create primary constraint on existing column use primary :::

unique

column.unique(options={[indexName:string],[deferrable:'not deferrable'|'immediate'|'deferred']})

Sets the column as unique. On Amazon Redshift, this constraint is not enforced, but it is used by the query planner. Deferrable unique constraint are supported on Postgres and Oracle and can be set by passing deferrable option to options object.

js
// @sql
knex.schema.table('users', function (table) {
  table
    .integer('user_id')
    .unique({ indexName: 'user_unique_id', deferrable: 'immediate' });
});

::: info If you want to create unique constraint on existing column use unique :::

references

column.references(column)

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.

js
// @sql
knex.schema.createTable('references_example', function (table) {
  table.integer('company_id').references('company.companyId');
});

inTable

column.inTable(table)

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

js
// @sql
knex.schema.createTable('in_table_example', function (table) {
  table.integer('company_id').references('companyId').inTable('company');
});

onDelete

column.onDelete(command)

Sets the SQL command to be run "onDelete".

js
// @sql
knex.schema.createTable('on_delete_example', function (table) {
  table
    .integer('company_id')
    .references('company.companyId')
    .onDelete('CASCADE');
});

onUpdate

column.onUpdate(command)

Sets the SQL command to be run "onUpdate".

js
// @sql
knex.schema.createTable('on_update_example', function (table) {
  table
    .integer('company_id')
    .references('company.companyId')
    .onUpdate('CASCADE');
});

defaultTo

column.defaultTo(value, options={[constraintName: string = undefined]))

Sets the default value for the column on an insert.

In MSSQL a constraintName option may be passed to ensure a specific constraint name:

js
// @sql
knex.schema.createTable('users', function (table) {
  table
    .string('column')
    .defaultTo('value', { constraintName: 'df_table_value' });
});

unsigned

column.unsigned()

Specifies a number as unsigned. Only for numeric values.

js
// @sql
knex.schema.createTable('unsigned_example', function (table) {
  table.integer('age').unsigned();
});

notNullable

column.notNullable()

Adds a not null on the current column being created.

js
// @sql
knex.schema.createTable('not_nullable_example', function (table) {
  table.string('email').notNullable();
});

nullable

column.nullable()

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

js
// @sql
knex.schema.createTable('nullable_example', function (table) {
  table.string('nickname').nullable();
});

first

column.first()

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

js
// @sql
knex.schema.table('users', function (table) {
  table.string('nickname').first();
});

after

column.after(field)

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

js
// @sql
knex.schema.table('users', function (table) {
  table.string('nickname').after('email');
});

comment

column.comment(value)

Sets the comment for a column.

js
// @sql
knex.schema.createTable('accounts', function (t) {
  t.increments().primary();
  t.string('email').unique().comment('This is the email field');
});

collate

column.collate(collation)

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

js
// @sql
knex.schema.createTable('users', function (t) {
  t.increments();
  t.string('email').unique().collate('utf8_unicode_ci');
});

View

columns

view.columns([columnNames])

Specify the columns of the view.

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.columns(['first_name', 'last_name']);
  view.as(knex('users').select('first_name').where('age', '>', '18'));
});

as

view.as(selectQuery)

Specify the select query of the view.

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.as(knex('users').select('first_name'));
});

checkOption [-SQ -MS -CR]

view.checkOption()

Add check option on the view definition. On OracleDb, MySQL, PostgreSQL and Redshift.

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.checkOption();
  view.as(knex('users').select('first_name'));
});

localCheckOption [-SQ -MS -OR -CR]

view.localCheckOption()

Add local check option on the view definition. On MySQL, PostgreSQL and Redshift.

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.localCheckOption();
  view.as(knex('users').select('first_name'));
});

cascadedCheckOption [-SQ -MS -OR -CR]

view.cascadedCheckOption()

Add cascaded check option on the view definition. On MySQL, PostgreSQL and Redshift.

js
// @sql
knex.schema.createView('users_view', function (view) {
  view.cascadedCheckOption();
  view.as(knex('users').select('first_name'));
});

Checks

check

table.check(checkPredicate, [bindings], [constraintName]))

Specify a check on table or column with raw predicate.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.integer('price_min');
  table.integer('price');
  table.check('?? >= ??', ['price', 'price_min']);
});

checkPositive

column.checkPositive([constraintName])

Specify a check on column that test if the value of column is positive.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.integer('price').checkPositive();
});

checkNegative

column.checkNegative([constraintName])

Specify a check on column that test if the value of column is negative.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.integer('price_decrease').checkNegative();
});

checkIn

column.checkIn(values, [constraintName])

Specify a check on column that test if the value of column is contained in a set of specified values.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.string('type').checkIn(['table', 'chair', 'sofa']);
});

checkNotIn

column.checkNotIn(values, [constraintName])

Specify a check on column that test if the value of column is not contains in a set of specified values.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.string('type').checkNotIn(['boot', 'shoe']);
});

checkBetween

column.checkBetween(values, [constraintName])

Specify a check on column that test if the value of column is within a range of values.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.integer('price').checkBetween([0, 100]);
});
// You can add checks on multiple intervals
// @sql
knex.schema.createTable('product', function (table) {
  table.integer('price').checkBetween([
    [0, 20],
    [30, 40],
  ]);
});

checkLength

column.checkLength(operator, length, [constraintName])

Specify a check on column that test if the length of a string match the predicate.

js
// @sql
knex.schema.createTable('product', function (table) {
  // operator can be =, !=, <=, >=, <, >
  table.string('phone').checkLength('=', 8);
});

checkRegex

column.checkRegex(regex, [constraintName])

Specify a check on column that test if the value match the specified regular expression. In MSSQL only simple pattern matching in supported but not regex syntax.

js
// @sql
knex.schema.createTable('product', function (table) {
  table.string('phone').checkRegex('[0-9]{8}');
  // In MSSQL, {8} syntax don't work,
  // you need to duplicate [0-9].
  table.string('phone').checkRegex('[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]');
});

dropChecks

table.dropChecks([checkConstraintNames])

Drop checks constraint given an array of constraint names.

js
// @sql
knex.schema.alterTable('product', function (table) {
  table.dropChecks(['price_check', 'price_proportion_check']);
});