Scala SQL DSL

Scala implementation of a really small subset of the SQL language

To understand how to write DSLs (internal/external) in Scala I started implementing a small subset of the SQL language.

Implemented:

select operation with fields
where clause with (typed) equals, in, and, or
order
A ‘renderer’ to create a SQL String from the given Query object

Scala SQL DSL lets you write stuff like:

scala> val q = select ("*") from ("user") where (("name","peter") and (("active", true) or ("role", "admin")))
scala> q.sql
res0: java.lang.String = select * from user where (name = 'peter' and (active = true or role = 'admin'))

Or using the parser:

scala> val sql = """select name,age from users where name = "peter" and (active = true or age = 30)"""
scala> val query = p.parse(sql).get
scala> AnsiSqlRenderer.sql(query)
res0: java.lang.String = select name,age from users where (name = 'peter' and (active = true or age = 30))

Prerequisites for building / running tests

maven2
maven uses the maven-scala-test plugin of which I have a for here: [http://github.com/p3t0r/maven-scalatest-plugin/] for running the specs

Usage

The spec contains various examples on how to write queries. But basically you start by:

Import all functions/implicits in the QueryBuilder object: import QueryBuilder._
Import the AnsiSqlRenderer object: AnsiSqlRenderer._

Author

Written by Peter Maas

License