This package provides a parser for a simplified SQL where clause conditional grammer, along with basic typechecking against a set of columns and the ability to emit clean SQL code for use in a query. It is intended to help support users in creating custom conditional filter statements in applications such as an analytics dashboard, with the knowledge that those filter statements are free from SQL injections or go beyond the capabilities of the grammer.
import pysqlfilter
columns = {'s': 'text', 'b': 'bool', 'i': 'int', 'f': 'real'}
pysqlfilter.parser.build_sql('s + \'lit\' > 1 and not b', columns=columns)
# (((s + \'lit\') > 1) and (not b))
pysqlfilter.parser.build_sql('1 + i / f > -0.1', columns=columns)
# ((1 + (i / f)) > (- 0.1))'
pysqlfilter.parser.build_sql('1 - s = f', columns=columns)
# throws: pysqlfilter.TypecheckError: expected integer, got varcharFor now all code lives in the sqlfilter.py file, and you can run a simple set of tests with python sqlfilter.py. You should see ----- Passed ----- at the end of the output if the tests work. (I'll switch this to pytest or something eventually)
Running python sqlfilter.py will also regenerate the railroad.svg file with any changes.
