https://github.com/3noch/postgresql-simple-interpolate

Safe interpolated SQL queries in Haskell
https://github.com/3noch/postgresql-simple-interpolate

haskell interpolation postgresql postgresql-database quasiquoter template-haskell

Last synced: 3 months ago
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Safe interpolated SQL queries in Haskell

• Host: GitHub
• URL: https://github.com/3noch/postgresql-simple-interpolate
• Owner: 3noch
• License: bsd-3-clause
• Created: 2019-08-17T21:58:41.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2023-06-16T15:20:01.000Z (over 1 year ago)
• Last Synced: 2024-10-11T23:42:29.369Z (4 months ago)
• Topics: haskell, interpolation, postgresql, postgresql-database, quasiquoter, template-haskell
• Language: Haskell
• Size: 21.5 KB
• Stars: 11
• Watchers: 5
• Forks: 2
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# `postgresql-simple-interpolate`

Write natural SQL statements in Haskell using a QuasiQuotes!

```haskell

{-# LANGUAGE QuasiQuotes #-}

import Data.Char (toLower)

import qualified Database.PostgreSQL.Simple as Pg

import Database.PostgreSQL.Simple.SqlQQ.Interpolated (isql)

import Control.Exception (bracket)

main :: IO ()

main = do

  bracket (Pg.connectPostgreSQL "host=localhost") Pg.close $ \conn -> do

    let limit = 10

    ages <- uncurry (query conn) [isql|SELECT age FROM table WHERE name = ${map toLower "CLIVE"} LIMIT ${limit}|]

    print (ages :: [Pg.Only Int])

|]

```

## Hacking

With Nix you can quickly play around with this using a PostgreSQL database:

```

nix-shell -p '(import ./. {}).haskellPackages.ghcWithPackages (p: [p.gargoyle-postgresql-connect p.postgresql-simple-interpolate])' --run ghci

```

Then run

```haskell

:set -XQuasiQuotes

import Gargoyle.PostgreSQL.Connect (withDb)

import Data.Pool (withResource)

import Database.PostgreSQL.Simple (Only (..), query)

import Database.PostgreSQL.Simple.SqlQQ.Interpolated (isql)

[isql|SELECT ${1 + 1}|]

-- ("SELECT ?",[Plain "2"])

withDb "db" $ \pool -> withResource pool $ \c -> (uncurry (query c) [isql|SELECT ${1 + 1}, ${reverse "HELLO"}::text|] :: IO [(Int, String)])

-- [(2,"OLLEH")]

```

## Acknowledgements

This library is basically just a copy of the [`here` package](https://github.com/tmhedberg/here) by Taylor M. Hedberg with slight modifications!