|
|
Relational an educational tool to provide a workspace for experimenting with *relational* *algebra*, an offshoot of first-order logic.
|
|
|
|
|
|
It works on GNU/Linux, Windows and OS X.
|
|
|
|
|
|
It provides:
|
|
|
* A GUI that can be used for executing relational queries
|
|
|
* A standalone Python module that can be used for executing relational queries, parsing relational expressions and optimizing them
|
|
|
* A command line interface
|
|
|
|
|
|
|
|
|
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))
|
|
|
ρ id➡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
|
|
|
```
|
|
|
|
|
|
or
|
|
|
|
|
|
```
|
|
|
python3 relational_gui.py
|
|
|
```
|
|
|
|
|
|
Running on OS X
|
|
|
===============
|
|
|
You can follow the instructions on running from sources to
|
|
|
run on OS X.
|
|
|
|
|
|
If you encounter problems, don't ask me for help. I don't have an Apple.
|
|
|
|
|
|
If you encounter problems and overcome them, please tell me how to update this
|
|
|
README.
|
|
|
|