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1 import keyword |
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2 from optparse import make_option |
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3 |
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4 from django.core.management.base import NoArgsCommand, CommandError |
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5 from django.db import connections, DEFAULT_DB_ALIAS |
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6 |
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7 class Command(NoArgsCommand): |
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8 help = "Introspects the database tables in the given database and outputs a Django model module." |
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9 |
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10 option_list = NoArgsCommand.option_list + ( |
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11 make_option('--database', action='store', dest='database', |
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12 default=DEFAULT_DB_ALIAS, help='Nominates a database to ' |
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13 'introspect. Defaults to using the "default" database.'), |
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14 ) |
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15 |
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16 requires_model_validation = False |
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17 |
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18 db_module = 'django.db' |
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19 |
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20 def handle_noargs(self, **options): |
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21 try: |
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22 for line in self.handle_inspection(options): |
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23 print line |
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24 except NotImplementedError: |
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25 raise CommandError("Database inspection isn't supported for the currently selected database backend.") |
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26 |
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27 def handle_inspection(self, options): |
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28 connection = connections[options.get('database', DEFAULT_DB_ALIAS)] |
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29 |
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30 table2model = lambda table_name: table_name.title().replace('_', '').replace(' ', '').replace('-', '') |
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31 |
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32 cursor = connection.cursor() |
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33 yield "# This is an auto-generated Django model module." |
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34 yield "# You'll have to do the following manually to clean this up:" |
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35 yield "# * Rearrange models' order" |
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36 yield "# * Make sure each model has one field with primary_key=True" |
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37 yield "# Feel free to rename the models, but don't rename db_table values or field names." |
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38 yield "#" |
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39 yield "# Also note: You'll have to insert the output of 'django-admin.py sqlcustom [appname]'" |
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40 yield "# into your database." |
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41 yield '' |
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42 yield 'from %s import models' % self.db_module |
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43 yield '' |
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44 for table_name in connection.introspection.get_table_list(cursor): |
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45 yield 'class %s(models.Model):' % table2model(table_name) |
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46 try: |
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47 relations = connection.introspection.get_relations(cursor, table_name) |
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48 except NotImplementedError: |
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49 relations = {} |
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50 try: |
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51 indexes = connection.introspection.get_indexes(cursor, table_name) |
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52 except NotImplementedError: |
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53 indexes = {} |
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54 for i, row in enumerate(connection.introspection.get_table_description(cursor, table_name)): |
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55 column_name = row[0] |
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56 att_name = column_name.lower() |
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57 comment_notes = [] # Holds Field notes, to be displayed in a Python comment. |
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58 extra_params = {} # Holds Field parameters such as 'db_column'. |
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59 |
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60 # If the column name can't be used verbatim as a Python |
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61 # attribute, set the "db_column" for this Field. |
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62 if ' ' in att_name or '-' in att_name or keyword.iskeyword(att_name) or column_name != att_name: |
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63 extra_params['db_column'] = column_name |
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64 |
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65 # Modify the field name to make it Python-compatible. |
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66 if ' ' in att_name: |
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67 att_name = att_name.replace(' ', '_') |
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68 comment_notes.append('Field renamed to remove spaces.') |
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69 if '-' in att_name: |
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70 att_name = att_name.replace('-', '_') |
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71 comment_notes.append('Field renamed to remove dashes.') |
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72 if keyword.iskeyword(att_name): |
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73 att_name += '_field' |
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74 comment_notes.append('Field renamed because it was a Python reserved word.') |
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75 if column_name != att_name: |
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76 comment_notes.append('Field name made lowercase.') |
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77 |
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78 if i in relations: |
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79 rel_to = relations[i][1] == table_name and "'self'" or table2model(relations[i][1]) |
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80 field_type = 'ForeignKey(%s' % rel_to |
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81 if att_name.endswith('_id'): |
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82 att_name = att_name[:-3] |
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83 else: |
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84 extra_params['db_column'] = column_name |
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85 else: |
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86 # Calling `get_field_type` to get the field type string and any |
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87 # additional paramters and notes. |
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88 field_type, field_params, field_notes = self.get_field_type(connection, table_name, row) |
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89 extra_params.update(field_params) |
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90 comment_notes.extend(field_notes) |
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91 |
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92 # Add primary_key and unique, if necessary. |
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93 if column_name in indexes: |
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94 if indexes[column_name]['primary_key']: |
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95 extra_params['primary_key'] = True |
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96 elif indexes[column_name]['unique']: |
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97 extra_params['unique'] = True |
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98 |
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99 field_type += '(' |
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100 |
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101 # Don't output 'id = meta.AutoField(primary_key=True)', because |
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102 # that's assumed if it doesn't exist. |
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103 if att_name == 'id' and field_type == 'AutoField(' and extra_params == {'primary_key': True}: |
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104 continue |
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105 |
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106 # Add 'null' and 'blank', if the 'null_ok' flag was present in the |
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107 # table description. |
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108 if row[6]: # If it's NULL... |
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109 extra_params['blank'] = True |
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110 if not field_type in ('TextField(', 'CharField('): |
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111 extra_params['null'] = True |
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112 |
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113 field_desc = '%s = models.%s' % (att_name, field_type) |
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114 if extra_params: |
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115 if not field_desc.endswith('('): |
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116 field_desc += ', ' |
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117 field_desc += ', '.join(['%s=%r' % (k, v) for k, v in extra_params.items()]) |
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118 field_desc += ')' |
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119 if comment_notes: |
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120 field_desc += ' # ' + ' '.join(comment_notes) |
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121 yield ' %s' % field_desc |
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122 for meta_line in self.get_meta(table_name): |
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123 yield meta_line |
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124 |
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125 def get_field_type(self, connection, table_name, row): |
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126 """ |
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127 Given the database connection, the table name, and the cursor row |
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128 description, this routine will return the given field type name, as |
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129 well as any additional keyword parameters and notes for the field. |
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130 """ |
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131 field_params = {} |
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132 field_notes = [] |
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133 |
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134 try: |
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135 field_type = connection.introspection.get_field_type(row[1], row) |
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136 except KeyError: |
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137 field_type = 'TextField' |
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138 field_notes.append('This field type is a guess.') |
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139 |
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140 # This is a hook for DATA_TYPES_REVERSE to return a tuple of |
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141 # (field_type, field_params_dict). |
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142 if type(field_type) is tuple: |
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143 field_type, new_params = field_type |
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144 field_params.update(new_params) |
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145 |
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146 # Add max_length for all CharFields. |
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147 if field_type == 'CharField' and row[3]: |
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148 field_params['max_length'] = row[3] |
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149 |
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150 if field_type == 'DecimalField': |
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151 field_params['max_digits'] = row[4] |
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152 field_params['decimal_places'] = row[5] |
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153 |
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154 return field_type, field_params, field_notes |
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155 |
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156 def get_meta(self, table_name): |
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157 """ |
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158 Return a sequence comprising the lines of code necessary |
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159 to construct the inner Meta class for the model corresponding |
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160 to the given database table name. |
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161 """ |
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162 return [' class Meta:', |
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163 ' db_table = %r' % table_name, |
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164 ''] |