Database-agnostic types and a composable SQL query builder for Gleam.
based provides a unified interface for interacting with SQL databases.
Adapter packages for specific database backends (e.g. PostgreSQL, MariaDB)
conform to the types and functions defined here.
gleam add basedBuild type-safe SQL queries using based/sql:
import database as db
import based/sql
let query =
sql.from(sql.table("users"))
|> sql.select([sql.column("id"), sql.column("name")])
|> sql.where([sql.column("id") |> sql.eq(db.int(1), of: sql.val)])
|> sql.to_query(adapter)
// query.sql == "SELECT id, name FROM users WHERE id = ?"
// query.values == [db.Int(1)]import based/sql
let inserter =
sql.rows([#("John", "john@example.com")])
|> sql.value("name", fn(user) { db.text(user.0) })
|> sql.value("email", fn(user) { db.text(user.1) })
let query =
sql.insert(into: sql.table("users"))
|> sql.values(inserter)
|> sql.to_query(adapter)
// query.sql == "INSERT INTO users (name, email) VALUES (?, ?)"import based/sql
let query =
sql.table("users")
|> sql.update([sql.set("name", db.text("Jane"), of: sql.val)])
|> sql.where([sql.column("id") |> sql.eq(db.int(1), of: sql.val)])
|> sql.to_query(adapter)
// query.sql == "UPDATE users SET name = ? WHERE id = ?"import based/sql
let query =
sql.from(sql.table("users"))
|> sql.delete()
|> sql.where([sql.column("id") |> sql.eq(db.int(1), of: sql.val)])
|> sql.to_query(adapter)
// query.sql == "DELETE FROM users WHERE id = ?"Use based.query, based.all, or based.one with a configured Db from an
adapter package:
import based
import gleam/dynamic/decode
let user_decoder = {
use id <- decode.field("id", decode.int)
use name <- decode.field("name", decode.string)
decode.success(User(id:, name:))
}
// `database` is provided by an adapter package
let assert Ok(users) = based.all(query, database, user_decoder)Adapter packages configure an sql.Adapter to control placeholder formatting,
identifier escaping, and value type mapping:
import based/sql
import gleam/int
let mysql_adapter =
sql.adapter()
|> sql.on_placeholder(with: fn(_) { "?" })
|> sql.on_identifier(with: fn(name) { "`" <> name <> "`" })
|> sql.on_value(with: my_value_to_string)
|> sql.on_null(with: fn() { MyNull })
|> sql.on_int(with: fn(i) { MyInt(i) })
|> sql.on_text(with: fn(s) { MyText(s) })Further documentation can be found at https://hexdocs.pm/based.
gleam test # Run the tests