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inspectdb fixer

Author:
kriberg
Posted:
May 12, 2009
Language:
Python
Version:
1.0
Score:
1 (after 1 ratings)

This snippet parses the output file of inspectdb and does some alterations. Mostly useful for people who regenerates models from constantly changing legacy databases.

The snippet will:

*Add quotes around foreign key classes, so the ordering is not significant

*Append a related_name property to each foreign key with the value model class name + db_column name to evade collisions in reverse queries like:

example.model: Reverse query name for field 'foreignkey' clashes with related field 'model2.foreignkey'. Add a related_name argument to the definition for 'foreignkey'.

There's a slight performance degradation with using quotes class name instead of passing the class though.

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import fileinput
import re
import sys

active_model = ""

for line in fileinput.input():
    if active_model == "" and not line.startswith("class"):
        sys.stdout.write(line)
        continue
    if line.startswith("#"):
        sys.stdout.write(line)
        continue
    if line.startswith("class"):
        active_model = re.findall("class\ (.*)\(models.Model\):", line)[0]
        sys.stdout.write(line)
        continue
    if "models.ForeignKey" in line:
        line = re.sub("ForeignKey\((.*),", "ForeignKey('\\1',", line)
        line = re.sub("''self''", "'self'", line)
        db_column = re.findall("db_column='(.*)'", line)[0]
        line = re.sub("\)$", ", related_name='%s_%s')" % (active_model.lower(), db_column), line)
        sys.stdout.write(line)
        continue
    sys.stdout.write(line)

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Comments

lauri (on April 1, 2010):

Nice idea, but it doesn't work in all cases. In particular it seems to fail in two ways for ForeignKey tables where the primary key ends in _id. Needs better re parsing.

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