ER Tools for Curry
==================

This directory contains tools for dealing with database applications
specified by entity-relationship diagrams (ERDs) in Curry programs.

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ERD2CDBI compiler
-----------------

This tool transforms an ERD term into datatypes used in the
Database.CDBI. libraries. It also creates an information file
for the currypp SQL-Parser.
If the tool is invoked with the option -db, it creates a
corresponding sqlite database.

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ERD2Curry compiler
------------------

This is a compiler for database applications
specified by entity-relationship diagrams (ERDs) into Curry programs.
The basic ideas and details about this approach are described in

B. Brassel, M. Hanus, M. Mueller:
High-Level Database Programming in Curry
In Proc. of the Tenth International Symposium on
Practical Aspects of Declarative Languages (PADL 2008),  pp. 316-332,
Springer LNCS 4902, 2008

Usage information:
------------------

Default use without Umbrello UML Modeller but ERD term descriptions:

1. Go to the directory where you want to create your Curry program and
   create an ERD description as a Curry term of type ERD
   (w.r.t. type definition given in module ERD.curry), e.g.,
   stored in "mymodel.erdterm".

2. Compile it into a Curry program with

       erd2curry mymodel.erdterm

   This generates two auxiliary files `ERDGeneric.curry` and
   `KeyDatabase.curry` and a main file `<Model name>.curry>`
   containing the Curry API operations to the database.


Use with Umbrello UML Modeller (no longer actively supported):

1. Create an XML description of the ERD (with Umbrello)
   in xmi format, e.g., stored in "mymodel.xmi".

2. Compile it into a Curry program with

   erd2curry -x myerd.xmi


Visualization:
--------------

To visualize an ERD term file as a graph with dotty, execute

erd2curry -v mymodel.erdterm


Examples:
---------

This directory contains two examples for ERD term files:

* `Blog.erdterm`: a simple ERD model for a blog with entries, comments,
  and tags.
* `Uni.erdterm`: an ERD model for university lectures as
  presented in the original paper cited above.

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Further infos and contact:
Michael Hanus <http://www.informatik.uni-kiel.de/~mh>
