django1/django/core/management/commands/inspectdb.py

128 lines
6.0 KiB
Python

from django.core.management.base import NoArgsCommand, CommandError
class Command(NoArgsCommand):
help = "Introspects the database tables in the given database and outputs a Django model module."
requires_model_validation = False
def handle_noargs(self, **options):
try:
for line in self.handle_inspection():
print line
except NotImplementedError:
raise CommandError("Database inspection isn't supported for the currently selected database backend.")
def handle_inspection(self):
from django.db import connection
import keyword
table2model = lambda table_name: table_name.title().replace('_', '').replace(' ', '').replace('-', '')
cursor = connection.cursor()
yield "# This is an auto-generated Django model module."
yield "# You'll have to do the following manually to clean this up:"
yield "# * Rearrange models' order"
yield "# * Make sure each model has one field with primary_key=True"
yield "# Feel free to rename the models, but don't rename db_table values or field names."
yield "#"
yield "# Also note: You'll have to insert the output of 'django-admin.py sqlcustom [appname]'"
yield "# into your database."
yield ''
yield 'from django.db import models'
yield ''
for table_name in connection.introspection.get_table_list(cursor):
yield 'class %s(models.Model):' % table2model(table_name)
try:
relations = connection.introspection.get_relations(cursor, table_name)
except NotImplementedError:
relations = {}
try:
indexes = connection.introspection.get_indexes(cursor, table_name)
except NotImplementedError:
indexes = {}
for i, row in enumerate(connection.introspection.get_table_description(cursor, table_name)):
column_name = row[0]
att_name = column_name.lower()
comment_notes = [] # Holds Field notes, to be displayed in a Python comment.
extra_params = {} # Holds Field parameters such as 'db_column'.
# If the column name can't be used verbatim as a Python
# attribute, set the "db_column" for this Field.
if ' ' in att_name or '-' in att_name or keyword.iskeyword(att_name) or column_name != att_name:
extra_params['db_column'] = column_name
# Modify the field name to make it Python-compatible.
if ' ' in att_name:
att_name = att_name.replace(' ', '_')
comment_notes.append('Field renamed to remove spaces.')
if '-' in att_name:
att_name = att_name.replace('-', '_')
comment_notes.append('Field renamed to remove dashes.')
if keyword.iskeyword(att_name):
att_name += '_field'
comment_notes.append('Field renamed because it was a Python reserved word.')
if column_name != att_name:
comment_notes.append('Field name made lowercase.')
if i in relations:
rel_to = relations[i][1] == table_name and "'self'" or table2model(relations[i][1])
field_type = 'ForeignKey(%s' % rel_to
if att_name.endswith('_id'):
att_name = att_name[:-3]
else:
extra_params['db_column'] = column_name
else:
try:
field_type = connection.introspection.data_types_reverse[row[1]]
except KeyError:
field_type = 'TextField'
comment_notes.append('This field type is a guess.')
# This is a hook for DATA_TYPES_REVERSE to return a tuple of
# (field_type, extra_params_dict).
if type(field_type) is tuple:
field_type, new_params = field_type
extra_params.update(new_params)
# Add max_length for all CharFields.
if field_type == 'CharField' and row[3]:
extra_params['max_length'] = row[3]
if field_type == 'DecimalField':
extra_params['max_digits'] = row[4]
extra_params['decimal_places'] = row[5]
# Add primary_key and unique, if necessary.
if column_name in indexes:
if indexes[column_name]['primary_key']:
extra_params['primary_key'] = True
elif indexes[column_name]['unique']:
extra_params['unique'] = True
field_type += '('
# Don't output 'id = meta.AutoField(primary_key=True)', because
# that's assumed if it doesn't exist.
if att_name == 'id' and field_type == 'AutoField(' and extra_params == {'primary_key': True}:
continue
# Add 'null' and 'blank', if the 'null_ok' flag was present in the
# table description.
if row[6]: # If it's NULL...
extra_params['blank'] = True
if not field_type in ('TextField(', 'CharField('):
extra_params['null'] = True
field_desc = '%s = models.%s' % (att_name, field_type)
if extra_params:
if not field_desc.endswith('('):
field_desc += ', '
field_desc += ', '.join(['%s=%r' % (k, v) for k, v in extra_params.items()])
field_desc += ')'
if comment_notes:
field_desc += ' # ' + ' '.join(comment_notes)
yield ' %s' % field_desc
yield ' class Meta:'
yield ' db_table = %r' % table_name
yield ''