| """ |
| This overrides the traditional `inspectdb` command so that geographic databases |
| may be introspected. |
| """ |
| |
| from django.core.management.commands.inspectdb import Command as InspectCommand |
| from django.contrib.gis.db.backend import SpatialBackend |
| |
| class Command(InspectCommand): |
| |
| # Mapping from lower-case OGC type to the corresponding GeoDjango field. |
| geofield_mapping = {'point' : 'PointField', |
| 'linestring' : 'LineStringField', |
| 'polygon' : 'PolygonField', |
| 'multipoint' : 'MultiPointField', |
| 'multilinestring' : 'MultiLineStringField', |
| 'multipolygon' : 'MultiPolygonField', |
| 'geometrycollection' : 'GeometryCollectionField', |
| 'geometry' : 'GeometryField', |
| } |
| |
| def geometry_columns(self): |
| """ |
| Returns a datastructure of metadata information associated with the |
| `geometry_columns` (or equivalent) table. |
| """ |
| # The `geo_cols` is a dictionary data structure that holds information |
| # about any geographic columns in the database. |
| geo_cols = {} |
| def add_col(table, column, coldata): |
| if table in geo_cols: |
| # If table already has a geometry column. |
| geo_cols[table][column] = coldata |
| else: |
| # Otherwise, create a dictionary indexed by column. |
| geo_cols[table] = { column : coldata } |
| |
| if SpatialBackend.name == 'postgis': |
| # PostGIS holds all geographic column information in the `geometry_columns` table. |
| from django.contrib.gis.models import GeometryColumns |
| for geo_col in GeometryColumns.objects.all(): |
| table = geo_col.f_table_name |
| column = geo_col.f_geometry_column |
| coldata = {'type' : geo_col.type, 'srid' : geo_col.srid, 'dim' : geo_col.coord_dimension} |
| add_col(table, column, coldata) |
| return geo_cols |
| elif SpatialBackend.name == 'mysql': |
| # On MySQL have to get all table metadata before hand; this means walking through |
| # each table and seeing if any column types are spatial. Can't detect this with |
| # `cursor.description` (what the introspection module does) because all spatial types |
| # have the same integer type (255 for GEOMETRY). |
| from django.db import connection |
| cursor = connection.cursor() |
| cursor.execute('SHOW TABLES') |
| tables = cursor.fetchall(); |
| for table_tup in tables: |
| table = table_tup[0] |
| table_desc = cursor.execute('DESCRIBE `%s`' % table) |
| col_info = cursor.fetchall() |
| for column, typ, null, key, default, extra in col_info: |
| if typ in self.geofield_mapping: add_col(table, column, {'type' : typ}) |
| return geo_cols |
| else: |
| # TODO: Oracle (has incomplete `geometry_columns` -- have to parse |
| # SDO SQL to get specific type, SRID, and other information). |
| raise NotImplementedError('Geographic database inspection not available.') |
| |
| def handle_inspection(self): |
| "Overloaded from Django's version to handle geographic database tables." |
| from django.db import connection |
| import keyword |
| |
| geo_cols = self.geometry_columns() |
| |
| table2model = lambda table_name: table_name.title().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.contrib.gis.db import models' |
| yield '' |
| for table_name in connection.introspection.get_table_list(cursor): |
| # Getting the geographic table dictionary. |
| geo_table = geo_cols.get(table_name, {}) |
| |
| 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)): |
| att_name, iatt_name = row[0].lower(), row[0] |
| comment_notes = [] # Holds Field notes, to be displayed in a Python comment. |
| extra_params = {} # Holds Field parameters such as 'db_column'. |
| |
| if ' ' in att_name: |
| extra_params['db_column'] = att_name |
| att_name = att_name.replace(' ', '') |
| comment_notes.append('Field renamed to remove spaces.') |
| if keyword.iskeyword(att_name): |
| extra_params['db_column'] = att_name |
| att_name += '_field' |
| comment_notes.append('Field renamed because it was a Python reserved word.') |
| |
| 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'] = att_name |
| else: |
| if iatt_name in geo_table: |
| ## Customization for Geographic Columns ## |
| geo_col = geo_table[iatt_name] |
| field_type = self.geofield_mapping[geo_col['type'].lower()] |
| # Adding extra keyword arguments for the SRID and dimension (if not defaults). |
| dim, srid = geo_col.get('dim', 2), geo_col.get('srid', 4326) |
| if dim != 2: extra_params['dim'] = dim |
| if srid != 4326: extra_params['srid'] = srid |
| 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. |
| column_name = extra_params.get('db_column', att_name) |
| 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 |
| if table_name in geo_cols: |
| yield ' objects = models.GeoManager()' |
| yield ' class Meta:' |
| yield ' db_table = %r' % table_name |
| yield '' |
