SQL query string builder

squel - SQL query string builder

A flexible and powerful SQL query string builder for Javascript.

Full documentation (guide and API) at http://squeljs.org/.

  • Works in node.js and in the browser.
  • Supports the standard SQL queries: SELECT, UPDATE, INSERT and DELETE.
  • Supports non-standard commands for popular DB engines such as MySQL.
  • Can be customized to build any query or command of your choosing.
  • Uses method chaining for ease of use.
  • Small: ~5 KB minified and gzipped
  • And much more, see the guide..

Install using npm:

$ npm install squel

Use bower if you like:

$ bower install squel

WARNING: Do not ever pass queries generated on the client side to your web server for execution. Such a configuration would make it trivial for a casual attacker to execute arbitrary queries—as with an SQL-injection vector, but much easier to exploit and practically impossible to protect against.

  • squel.js - unminified version of Squel with the standard commands and all available non-standard commands added
  • squel.min.js - minified version of squel.js
  • squel-basic.js - unminified version of Squel with only the standard SQL commands
  • squel-basic.min.js - minified version of squel-basic.js

Before running the examples ensure you have squel installed and enabled at the top of your script:

var squel = require("squel");
// SELECT * FROM table 
// SELECT `t1`.`id`, `t1`.`name` as "My name", `t1`.`started` as "Date" FROM table `t1` ORDER BY id ASC LIMIT 20 
squel.select({ autoQuoteFieldNames: true })
    .from("table", "t1")
    .field("t1.name", "My name")
    .field("t1.started", "Date")
// SELECT t1.id, t2.name FROM table `t1` LEFT JOIN table2 `t2` ON (t1.id = t2.id) WHERE (t2.name <> 'Mark') AND (t2.name <> 'John') GROUP BY t1.id 
    .from("table", "t1")
    .left_join("table2", "t2", "t1.id = t2.id")
    .where("t2.name <> 'Mark'")
    .where("t2.name <> 'John'")

You can use nested queries too:

// SELECT s.id FROM (SELECT * FROM students) `s` INNER JOIN (SELECT id FROM marks) `m` ON (m.id = s.id) 
    .from( squel.select().from('students'), 's' )
    .join( squel.select().from('marks').field('id'), 'm', 'm.id = s.id' )
// UPDATE test SET f1 = 1 
    .set("f1", 1)
// UPDATE test, test2, test3 AS `a` SET test.id = 1, test2.val = 1.2, a.name = "Ram", a.email = NULL, a.count = a.count + 1 
    .set("test.id", 1)
    .set("test2.val", 1.2)
        "a.name": "Ram",
        "a.email": null,
        "a.count = a.count + 1": undefined
// INSERT INTO test (f1) VALUES (1) 
    .set("f1", 1)
// INSERT INTO test (name, age) VALUES ('Thomas', 29), ('Jane', 31) 
        { name: "Thomas", age: 29 },
        { name: "Jane", age: 31 }    
// DELETE FROM test 
// DELETE FROM table1 WHERE (table1.id = 2) ORDER BY id DESC LIMIT 2 
    .where("table1.id = ?", 2)
    .order("id", false)

Use the useParam() method to obtain a parameterized query with a separate list of formatted parameter values:

// { text: "INSERT INTO test (f1, f2, f3, f4, f5) VALUES (?, ?, ?, ?, ?)", values: [1, 1.2, "TRUE", "blah", "NULL"] } 
    .set("f1", 1)
    .set("f2", 1.2)
    .set("f3", true)
    .set("f4", "blah")
    .set("f5", null)

There is also an expression builder which allows you to build complex expressions for WHERE and ON clauses:

// test = 3 OR test = 4 
    .or("test = 3")
    .or("test = 4")
// test = 3 AND (inner = 1 OR inner = 2) OR (inner = 3 AND inner = 4 OR (inner IN ('str1, 'str2', NULL))) 
    .and("test = 3")
        .or("inner = 1")
        .or("inner = 2")
        .and("inner = ?", 3)
        .and("inner = ?", 4)
            .and("inner IN ?", ['str1', 'str2', null])
// SELECT * FROM test INNER JOIN test2 ON (test.id = test2.id) WHERE (test = 3 OR test = 4) 
    .join( "test2", null, squel.expr().and("test.id = test2.id") )
    .where( squel.expr().or("test = 3").or("test = 4") )

By default Squel does not support the use of object instances as field values. Instead it lets you tell it how you want specific object types to be handled:

// handler for objects of type Date 
squel.registerValueHandler(Date, function(date) {
  return date.getFullYear() + '/' + (date.getMonth() + 1) + '/' + date.getDate();
  .set('start_date', new Date(2013, 5, 1))
// UPDATE students SET start_date = '2013/6/1' 

Note that custom value handlers can be overridden on a per-instance basis (see the docs)

Squel allows you to override the built-in query builders with your own as well as create your own types of queries:

// ------------------------------------------------------ 
// Setup the PRAGMA query builder 
// ------------------------------------------------------ 
var util = require('util');   // to use util.inherits() from node.js 
var CommandBlock = function() {};
util.inherits(CommandBlock, squel.cls.Block);
// private method - will not get exposed within the query builder 
CommandBlock.prototype._command = function(_command) {
  this._command = _command;
// public method - will get exposed within the query builder 
CommandBlock.prototype.compress = function() {
CommandBlock.prototype.buildStr = function() {
  return this._command.toUpperCase();
// generic parameter block 
var ParamBlock = function() {};
util.inherits(ParamBlock, squel.cls.Block);
ParamBlock.prototype.param = function(p) {
  this._p = p;
ParamBlock.prototype.buildStr = function() {
  return this._p;
// pragma query builder 
var PragmaQuery = function(options) {
  squel.cls.QueryBuilder.call(this, options, [
      new squel.cls.StringBlock(options, 'PRAGMA'),
      new CommandBlock(),
      new ParamBlock()
util.inherits(PragmaQuery, squel.cls.QueryBuilder);
// convenience method (we can override built-in squel methods this way too) 
squel.pragma = function(options) {
  return new PragmaQuery(options)
// ------------------------------------------------------ 
// Build a PRAGMA query 
// ------------------------------------------------------ 

Examples of custom queries in the wild:

Squel supports the standard SQL commands and reserved words. However a number of database engines provide their own non-standard commands. To make things easy Squel allows for different 'flavours' of SQL to be loaded and used.

At the moment Squel provides mysql, mssql and postgres flavours which augment query builders with additional commands (e.g. INSERT ... RETURNING for use with Postgres).

To use this in node.js:

var squel = require('squel').useFlavour('postgres');

For the browser:

<script type="text/javascript" src="https://rawgithub.com/hiddentao/squel/master/squel.min.js"></script>
<script type="text/javascript">
  squel = squel.useFlavour('postgres');

(Internally the flavour setup method simply utilizes the custom query mechanism to effect changes).

Read the the API docs to find out available commands. Flavours of SQL which get added to Squel in the future will be usable in the above manner.

To build the code and run the tests:

$ npm install -g grunt-cli
$ npm install
$ grunt <-- this will build the code and run the tests

Contributions are welcome! Please see CONTRIBUTING.md.

MIT - see LICENSE.md