relational/README.md

Relational an educational tool to provide a workspace for experimenting with *relational* *algebra*, an offshoot of first-order logic.

It provides GUI that can be used for executing relational queries, and also provides a command line interface.

Provides a standalone Python module that can be used for executing relational queries, parsing relational expressions and optimizing them.

Official website
================

More documentation can be found here http://ltworf.github.io/relational/


Install
=======

Binary download for Windows can be obtained from the website.

For Linux, check your distribution's packages, relational is available on Debian and Ubuntu.


Syntax
======

These are some valid queries

```
σage > 25 and rank == weight(A)
σ (name.upper().startswith('J') and age>21 )(people)
Q ⋈ π a,b(A) ⋈ B
ρid➡i,name➡n(A) - π a,b(π a,b(A)) ∩ σage > 25 or rank = weight(A)
π a,b(π a,b(A))
ρid➡i,name➡n(π a,b(A))
A ⋈ B
```


Run from sources
================
If it needs some dependencies:
 * Qt5
 * Python 3.4 or greater
 * PyQt5
 * pyuic5 and pyrcc5

You will need to run
```
make
```
to generate some .py files.

To launch the application, run

```
./relational_gui.py
```

Running on osx
==============

You can probably follow the instructions on running from sources to
rut on osx.

If you encounter problems, don't ask me for help.

If you encounter problems and overcome them, please tell me how to update this
README.