node/doc/api/sqlite.md

SQLite

Stability: 1.1 - Active development.

The node:sqlite module facilitates working with SQLite databases. To access it:

import sqlite from 'node:sqlite';

const sqlite = require('node:sqlite');

This module is only available under the node: scheme.

The following example shows the basic usage of the node:sqlite module to open an in-memory database, write data to the database, and then read the data back.

import { DatabaseSync } from 'node:sqlite';
const database = new DatabaseSync(':memory:');

// Execute SQL statements from strings.
database.exec(`
  CREATE TABLE data(
    key INTEGER PRIMARY KEY,
    value TEXT
  ) STRICT
`);
// Create a prepared statement to insert data into the database.
const insert = database.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
// Execute the prepared statement with bound values.
insert.run(1, 'hello');
insert.run(2, 'world');
// Create a prepared statement to read data from the database.
const query = database.prepare('SELECT * FROM data ORDER BY key');
// Execute the prepared statement and log the result set.
console.log(query.all());
// Prints: [ { key: 1, value: 'hello' }, { key: 2, value: 'world' } ]

'use strict';
const { DatabaseSync } = require('node:sqlite');
const database = new DatabaseSync(':memory:');

// Execute SQL statements from strings.
database.exec(`
  CREATE TABLE data(
    key INTEGER PRIMARY KEY,
    value TEXT
  ) STRICT
`);
// Create a prepared statement to insert data into the database.
const insert = database.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
// Execute the prepared statement with bound values.
insert.run(1, 'hello');
insert.run(2, 'world');
// Create a prepared statement to read data from the database.
const query = database.prepare('SELECT * FROM data ORDER BY key');
// Execute the prepared statement and log the result set.
console.log(query.all());
// Prints: [ { key: 1, value: 'hello' }, { key: 2, value: 'world' } ]

Class: DatabaseSync

This class represents a single connection to a SQLite database. All APIs exposed by this class execute synchronously.

new DatabaseSync(location[, options])

• location {string} The location of the database. A SQLite database can be stored in a file or completely in memory. To use a file-backed database, the location should be a file path. To use an in-memory database, the location should be the special name ':memory:'.
• options {Object} Configuration options for the database connection. The following options are supported:
  • open {boolean} If true, the database is opened by the constructor. When this value is false, the database must be opened via the open() method. Default: true.
  • readOnly {boolean} If true, the database is opened in read-only mode. If the database does not exist, opening it will fail. Default: false.
  • enableForeignKeyConstraints {boolean} If true, foreign key constraints are enabled. This is recommended but can be disabled for compatibility with legacy database schemas. The enforcement of foreign key constraints can be enabled and disabled after opening the database using PRAGMA foreign_keys. Default: true.
  • enableDoubleQuotedStringLiterals {boolean} If true, SQLite will accept double-quoted string literals. This is not recommended but can be enabled for compatibility with legacy database schemas. Default: false.

Constructs a new DatabaseSync instance.

database.close()

Closes the database connection. An exception is thrown if the database is not open. This method is a wrapper around sqlite3_close_v2().

database.exec(sql)

• sql {string} A SQL string to execute.

This method allows one or more SQL statements to be executed without returning any results. This method is useful when executing SQL statements read from a file. This method is a wrapper around sqlite3_exec().

database.open()

Opens the database specified in the location argument of the DatabaseSync constructor. This method should only be used when the database is not opened via the constructor. An exception is thrown if the database is already open.

database.prepare(sql)

• sql {string} A SQL string to compile to a prepared statement.
• Returns: {StatementSync} The prepared statement.

Compiles a SQL statement into a prepared statement. This method is a wrapper around sqlite3_prepare_v2().

database.createSession([options])

• options {Object} The configuration options for the session.
  • table {string} A specific table to track changes for. By default, changes to all tables are tracked.
  • db {string} Name of the database to track. This is useful when multiple databases have been added using ATTACH DATABASE. Default: 'main'.
• Returns: {Session} A session handle.

Creates and attaches a session to the database. This method is a wrapper around sqlite3session_create() and sqlite3session_attach().

database.applyChangeset(changeset[, options])

• changeset {Uint8Array} A binary changeset or patchset.
• options {Object} The configuration options for how the changes will be applied.
  • filter {Function} Skip changes that, when targeted table name is supplied to this function, return a truthy value. By default, all changes are attempted.
  • onConflict {number} Determines how conflicts are handled. Default: SQLITE_CHANGESET_ABORT.
    • SQLITE_CHANGESET_OMIT: conflicting changes are omitted.
    • SQLITE_CHANGESET_REPLACE: conflicting changes replace existing values.
    • SQLITE_CHANGESET_ABORT: abort on conflict and roll back databsase.
• Returns: {boolean} Whether the changeset was applied succesfully without being aborted.

An exception is thrown if the database is not open. This method is a wrapper around sqlite3changeset_apply().

const sourceDb = new DatabaseSync(':memory:');
const targetDb = new DatabaseSync(':memory:');

sourceDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
targetDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');

const session = sourceDb.createSession();

const insert = sourceDb.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
insert.run(1, 'hello');
insert.run(2, 'world');

const changeset = session.changeset();
targetDb.applyChangeset(changeset);
// Now that the changeset has been applied, targetDb contains the same data as sourceDb.

Class: Session

session.changeset()

• Returns: {Uint8Array} Binary changeset that can be applied to other databases.

Retrieves a changeset containing all changes since the changeset was created. Can be called multiple times. An exception is thrown if the database or the session is not open. This method is a wrapper around sqlite3session_changeset().

session.patchset()

• Returns: {Uint8Array} Binary patchset that can be applied to other databases.

Similar to the method above, but generates a more compact patchset. See Changesets and Patchsets in the documentation of SQLite. An exception is thrown if the database or the session is not open. This method is a wrapper around sqlite3session_patchset().

session.close().

Closes the session. An exception is thrown if the database or the session is not open. This method is a wrapper around sqlite3session_delete().

Class: StatementSync

This class represents a single prepared statement. This class cannot be instantiated via its constructor. Instead, instances are created via the database.prepare() method. All APIs exposed by this class execute synchronously.

A prepared statement is an efficient binary representation of the SQL used to create it. Prepared statements are parameterizable, and can be invoked multiple times with different bound values. Parameters also offer protection against SQL injection attacks. For these reasons, prepared statements are preferred over hand-crafted SQL strings when handling user input.

statement.all([namedParameters][, ...anonymousParameters])

• namedParameters {Object} An optional object used to bind named parameters. The keys of this object are used to configure the mapping.
• ...anonymousParameters {null|number|bigint|string|Buffer|Uint8Array} Zero or more values to bind to anonymous parameters.
• Returns: {Array} An array of objects. Each object corresponds to a row returned by executing the prepared statement. The keys and values of each object correspond to the column names and values of the row.

This method executes a prepared statement and returns all results as an array of objects. If the prepared statement does not return any results, this method returns an empty array. The prepared statement parameters are bound using the values in namedParameters and anonymousParameters.

statement.expandedSQL

• {string} The source SQL expanded to include parameter values.

The source SQL text of the prepared statement with parameter placeholders replaced by the values that were used during the most recent execution of this prepared statement. This property is a wrapper around sqlite3_expanded_sql().

statement.get([namedParameters][, ...anonymousParameters])

• namedParameters {Object} An optional object used to bind named parameters. The keys of this object are used to configure the mapping.
• ...anonymousParameters {null|number|bigint|string|Buffer|Uint8Array} Zero or more values to bind to anonymous parameters.
• Returns: {Object|undefined} An object corresponding to the first row returned by executing the prepared statement. The keys and values of the object correspond to the column names and values of the row. If no rows were returned from the database then this method returns undefined.

This method executes a prepared statement and returns the first result as an object. If the prepared statement does not return any results, this method returns undefined. The prepared statement parameters are bound using the values in namedParameters and anonymousParameters.

statement.run([namedParameters][, ...anonymousParameters])

• namedParameters {Object} An optional object used to bind named parameters. The keys of this object are used to configure the mapping.
• ...anonymousParameters {null|number|bigint|string|Buffer|Uint8Array} Zero or more values to bind to anonymous parameters.
• Returns: {Object}
  • changes: {number|bigint} The number of rows modified, inserted, or deleted by the most recently completed INSERT, UPDATE, or DELETE statement. This field is either a number or a BigInt depending on the prepared statement's configuration. This property is the result of sqlite3_changes64().
  • lastInsertRowid: {number|bigint} The most recently inserted rowid. This field is either a number or a BigInt depending on the prepared statement's configuration. This property is the result of sqlite3_last_insert_rowid().

This method executes a prepared statement and returns an object summarizing the resulting changes. The prepared statement parameters are bound using the values in namedParameters and anonymousParameters.

statement.setAllowBareNamedParameters(enabled)

• enabled {boolean} Enables or disables support for binding named parameters without the prefix character.

The names of SQLite parameters begin with a prefix character. By default, node:sqlite requires that this prefix character is present when binding parameters. However, with the exception of dollar sign character, these prefix characters also require extra quoting when used in object keys.

To improve ergonomics, this method can be used to also allow bare named parameters, which do not require the prefix character in JavaScript code. There are several caveats to be aware of when enabling bare named parameters:

• The prefix character is still required in SQL.
• The prefix character is still allowed in JavaScript. In fact, prefixed names will have slightly better binding performance.
• Using ambiguous named parameters, such as $k and @k, in the same prepared statement will result in an exception as it cannot be determined how to bind a bare name.

statement.setReadBigInts(enabled)

• enabled {boolean} Enables or disables the use of BigInts when reading INTEGER fields from the database.

When reading from the database, SQLite INTEGERs are mapped to JavaScript numbers by default. However, SQLite INTEGERs can store values larger than JavaScript numbers are capable of representing. In such cases, this method can be used to read INTEGER data using JavaScript BigInts. This method has no impact on database write operations where numbers and BigInts are both supported at all times.

statement.sourceSQL

• {string} The source SQL used to create this prepared statement.

The source SQL text of the prepared statement. This property is a wrapper around sqlite3_sql().

Type conversion between JavaScript and SQLite

When Node.js writes to or reads from SQLite it is necessary to convert between JavaScript data types and SQLite's data types. Because JavaScript supports more data types than SQLite, only a subset of JavaScript types are supported. Attempting to write an unsupported data type to SQLite will result in an exception.

SQLite	JavaScript
NULL	{null}
INTEGER	{number} or {bigint}
REAL	{number}
TEXT	{string}
BLOB	{Uint8Array}

SQLite constants

The following constants are exported by the node:sqlite module.

SQLite Session constants

Conflict-resolution constants

The following constants are meant for use with database.applyChangeset().

Constant	Description
SQLITE_CHANGESET_OMIT	Conflicting changes are omitted.
SQLITE_CHANGESET_REPLACE	Conflicting changes replace existing values.
SQLITE_CHANGESET_ABORT	Abort when a change encounters a conflict and roll back databsase.