a30aac5f5b
It was not really easy to write the name for the result in a separate box, and it would create a lot of garbage results, by creating a new one per every query. Now single lines queries can contain assignments, and if not a default relation named 'last_' is used to hold the last result.
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.