The esqueleto package

[Tags:bsd3, library, test]

persistent is a library for type-safe data serialization. It has many kinds of backends, such as SQL backends (persistent-mysql, persistent-postgresql, persistent-sqlite) and NoSQL backends (persistent-mongoDB).

While persistent is a nice library for storing and retrieving records, currently it has a poor interface for SQL backends compared to SQL itself. For example, it's extremely hard to do a type-safe JOIN on a many-to-one relation, and simply impossible to do any other kinds of JOINs (including for the very common many-to-many relations). Users have the option of writing raw SQL, but that's error prone and not type-checked.

esqueleto is a bare bones, type-safe EDSL for SQL queries that works with unmodified persistent SQL backends. Its language closely resembles SQL, so (a) you don't have to learn new concepts, just new syntax, and (b) it's fairly easy to predict the generated SQL and optimize it for your backend. Most kinds of errors committed when writing SQL are caught as compile-time errors---although it is possible to write type-checked esqueleto queries that fail at runtime.

Currently, SELECTs, UPDATEs, INSERTs and DELETEs are supported. Not all SQL features are available, but most of them can be easily added (especially functions), so please open an issue or send a pull request if you need anything that is not covered by esqueleto on

The name of this library means "skeleton" in Portuguese and contains all three SQL letters in the correct order =). It was inspired by Scala's Squeryl but created from scratch.


Versions 0.1, 0.2, 0.2.1, 0.2.2, 0.2.3, 0.2.4, 0.2.5, 0.2.6, 0.2.7, 0.2.8, 0.2.9, 1.0, 1.0.1, 1.0.2, 1.0.3, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.2, 1.2.1, 1.2.2,, 1.2.3, 1.2.4, 1.3, 1.3.1, 1.3.2, 1.3.3, 1.3.4,,,,,, 1.3.5, 1.3.6, 1.3.7, 1.3.8, 1.3.9, 1.3.10, 1.3.11, 1.3.12, 1.4, 1.4.1,,,, 1.4.2, 1.4.3, 1.4.4, 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.1.0, 2.1.1, 2.1.2,,,, 2.1.3, 2.2, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 2.2.6, 2.2.7, 2.2.8, 2.2.9, 2.2.10, 2.2.11, 2.2.12, 2.3.0, 2.4.0, 2.4.1, 2.4.2, 2.4.3, 2.5.0, 2.5.1, 2.5.2, 2.5.3 (info)
Dependencies base (>=4.5 && <4.8), conduit, monad-logger, persistent (==1.3.*), resourcet, tagged (>=0.2), text (>=0.11), transformers (>=0.2), unordered-containers (>=0.2) [details]
License BSD3
Copyright (c) 2012-2014 Felipe Almeida Lessa
Author Felipe Lessa
Category Database
Home page
Source repository head: git clone git://
Uploaded Wed Apr 2 16:25:45 UTC 2014 by FelipeLessa
Distributions Arch:2.5.3, Debian:2.4.1, FreeBSD:2.4.1, LTSHaskell:2.5.3, NixOS:2.5.3, Stackage:2.5.3, Tumbleweed:2.5.3
Downloads 29727 total (502 in the last 30 days)
1 []
Status Docs available [build log]
Successful builds reported [all 1 reports]
Hackage Matrix CI





test postgresql. default is to test sqlite.


test MySQL/MariaDB. default is to test sqlite.


Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info


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