Regal: An SQL relational algebra builder

[Dylan Knutson via Digitalmars-d-announce]

Hi all,

I'd like to announce the initial version of Regal, an SQL 
relational algebra builder for D. It's intended as a backbone for 
a relational database ORM, in line with how Arel works with 
Rails' ActiveRecord, but nearly any project that generates SQL 
dynamically can benefit from it. The goal of the library is to 
make programmatically generating queries simple (and more robust 
than simple string concatenation), and to be database agnostic 
(it's very easy to write database specific printers for a Regal 
AST).

There are extensive examples available in the Readme about how to 
use the library, from generating very simple queries (SELECT * 
FROM users) to multiple chained joins and nested constraints. 
Here's an example from the documentation: finding a user with ID 
1:

```
auto users = new Table(
   "users", // table name
   "id",    // the rest are columns
   "name",
   "created_at",
   "updated_at");

// SELECT * FROM users WHERE users.id = 1 LIMIT 1
users
   .where(users.id.eq(1))
   .limit(1)
   .project(new Sql("*"))
   .to_sql
```

The library can be found at: https://github.com/dymk/regal
And the dub package: http://code.dlang.org/packages/regal

Please let me know if you find any bugs via the Github tracker!

Regards,
Dylan