Fixed #1286 -- Improved 'inspectdb' so that it introspects primary_key=True and…

Fixed #1286 -- Improved 'inspectdb' so that it introspects primary_key=True and unique=True for MySQL. Thanks, gandalf@owca.info

git-svn-id: http://code.djangoproject.com/svn/django/trunk@2346 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -51,6 +51,7 @@ answer newbie questions, and generally made Django that much better:
     deric@monowerks.com
     Jeremy Dunck <http://dunck.us/>
     Clint Ecker
+    gandalf@owca.info
     Baishampayan Ghose
     Espen Grindhaug <http://grindhaug.org/>
     Gustavo Picon

django/core/db/__init__.py

@@ -37,6 +37,7 @@ get_random_function_sql = dbmod.get_random_function_sql
 get_table_list = dbmod.get_table_list
 get_table_description = dbmod.get_table_description
 get_relations = dbmod.get_relations
+get_indexes = dbmod.get_indexes
 OPERATOR_MAPPING = dbmod.OPERATOR_MAPPING
 DATA_TYPES = dbmod.DATA_TYPES
 DATA_TYPES_REVERSE = dbmod.DATA_TYPES_REVERSE

django/core/db/backends/ado_mssql.py

@@ -118,6 +118,9 @@ def get_table_description(cursor, table_name):
 def get_relations(cursor, table_name):
     raise NotImplementedError
 
+def get_indexes(cursor, table_name):
+    raise NotImplementedError
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',

django/core/db/backends/mysql.py

@@ -135,6 +135,14 @@ def get_table_description(cursor, table_name):
 def get_relations(cursor, table_name):
     raise NotImplementedError
 
+def get_indexes(cursor, table_name):
+    "Returns a dict of indexes for given table"
+    cursor.execute("SHOW INDEX FROM %s" % DatabaseWrapper().quote_name(table_name))
+    indexes = {}
+    for row in cursor.fetchall():
+        indexes[row[4]] = {'keyname': row[2], 'unique': not bool(row[1])}
+    return indexes
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',

django/core/db/backends/postgresql.py

@@ -126,6 +126,9 @@ def get_relations(cursor, table_name):
             continue
     return relations
 
+def get_indexes(cursor, table_name):
+    raise NotImplementedError
+
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
 # use mx.DateTime by default.

django/core/db/backends/sqlite3.py

@@ -134,6 +134,9 @@ def get_table_description(cursor, table_name):
 def get_relations(cursor, table_name):
     raise NotImplementedError
 
+def get_indexes(cursor, table_name):
+    raise NotImplementedError
+
 # Operators and fields ########################################################
 
 # SQLite requires LIKE statements to include an ESCAPE clause if the value

django/core/management.py

@@ -595,23 +595,27 @@ def inspectdb(db_name):
             relations = db.get_relations(cursor, table_name)
         except NotImplementedError:
             relations = {}
+        try:
+            indexes = db.get_indexes(cursor, table_name)
+        except NotImplementedError:
+            indexes = {}
         for i, row in enumerate(db.get_table_description(cursor, table_name)):
-            column_name = row[0]
+            att_name = row[0]
             comment_notes = [] # Holds Field notes, to be displayed in a Python comment.
             extra_params = {}  # Holds Field parameters such as 'db_column'.
 
-            if keyword.iskeyword(column_name):
-                extra_params['db_column'] = column_name
-                column_name += '_field'
+            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 relations.has_key(i):
                 rel_to = relations[i][1] == table_name and "'self'" or table2model(relations[i][1])
                 field_type = 'ForeignKey(%s' % rel_to
-                if column_name.endswith('_id'):
-                    column_name = column_name[:-3]
+                if att_name.endswith('_id'):
+                    att_name = att_name[:-3]
                 else:
-                    extra_params['db_column'] = column_name
+                    extra_params['db_column'] = att_name
             else:
                 try:
                     field_type = db.DATA_TYPES_REVERSE[row[1]]
@@ -625,12 +629,26 @@ def inspectdb(db_name):
                     field_type, new_params = field_type
                     extra_params.update(new_params)
 
+                # Add maxlength for all CharFields.
                 if field_type == 'CharField' and row[3]:
                     extra_params['maxlength'] = row[3]
 
+                # 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]['keyname'] == 'PRIMARY':
+                        extra_params['primary_key'] = True
+                    elif indexes[column_name]['unique']:
+                        extra_params['unique'] = True
+
                 field_type += '('
 
-            field_desc = '%s = meta.%s' % (column_name, 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
+
+            field_desc = '%s = meta.%s' % (att_name, field_type)
             if extra_params:
                 if not field_desc.endswith('('):
                     field_desc += ', '

docs/django-admin.txt

@@ -112,12 +112,13 @@ output:
 
 This feature is meant as a shortcut, not as definitive model generation. After
 you run it, you'll want to look over the generated models yourself to make
-customizations. In particular, you'll need to do this:
+customizations. In particular, you'll need to rearrange models' order, so that
+models that refer to other models are ordered properly.
 
-    * Rearrange models' order, so that models that refer to other models are
-      ordered properly.
-    * Add ``primary_key=True`` to one field in each model. The ``inspectdb``
-      doesn't yet introspect primary keys.
+If you're using Django 0.90 or 0.91, you'll need to add ``primary_key=True`` to
+one field in each model. In the Django development version, primary keys are
+automatically introspected for MySQL, and Django puts in the
+``primary_key=True`` where needed.
 
 ``inspectdb`` works with PostgreSQL, MySQL and SQLite. Foreign-key detection
 only works in PostgreSQL.