cd6bd42a2b
This uses the CallableString object only in the final step and not during all the intermediate ones. Since str is a native object, it is faster to use than a normal object. This is a very marginal optimization that will not yield any gains :)
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.