Fixed #5461 -- Refactored the database backend code to use classes for the creation and introspection modules. Introduces a new validation module for DB-specific validation. This is a backwards incompatible change; see the wiki for details.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8296 bcc190cf-cafb-0310-a4f2-bffc1f526a37

4 files changed, 149 insertions, 128 deletions

diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 1dfe34aceb..4a8d6ebef0 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -4,9 +4,13 @@ PostgreSQL database backend for Django.
 Requires psycopg 1: http://initd.org/projects/psycopg1
 """
 
-from django.utils.encoding import smart_str, smart_unicode
-from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, util
+from django.db.backends import *
+from django.db.backends.postgresql.client import DatabaseClient
+from django.db.backends.postgresql.creation import DatabaseCreation
+from django.db.backends.postgresql.introspection import DatabaseIntrospection
 from django.db.backends.postgresql.operations import DatabaseOperations
+from django.utils.encoding import smart_str, smart_unicode
+
 try:
     import psycopg as Database
 except ImportError, e:
@@ -59,12 +63,7 @@ class UnicodeCursorWrapper(object):
     def __iter__(self):
         return iter(self.cursor)
 
-class DatabaseFeatures(BaseDatabaseFeatures):
-    pass # This backend uses all the defaults.
-
 class DatabaseWrapper(BaseDatabaseWrapper):
-    features = DatabaseFeatures()
-    ops = DatabaseOperations()
     operators = {
         'exact': '= %s',
         'iexact': 'ILIKE %s',
@@ -82,6 +81,16 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         'iendswith': 'ILIKE %s',
     }
 
+    def __init__(self, *args, **kwargs):
+        super(DatabaseWrapper, self).__init__(*args, **kwargs)
+        
+        self.features = BaseDatabaseFeatures()
+        self.ops = DatabaseOperations()
+        self.client = DatabaseClient()
+        self.creation = DatabaseCreation(self)
+        self.introspection = DatabaseIntrospection(self)
+        self.validation = BaseDatabaseValidation()
+
     def _cursor(self, settings):
         set_tz = False
         if self.connection is None:
diff --git a/django/db/backends/postgresql/client.py b/django/db/backends/postgresql/client.py
index 8123ec7848..28daed833a 100644
--- a/django/db/backends/postgresql/client.py
+++ b/django/db/backends/postgresql/client.py
@@ -1,15 +1,17 @@
+from django.db.backends import BaseDatabaseClient
 from django.conf import settings
 import os
 
-def runshell():
-    args = ['psql']
-    if settings.DATABASE_USER:
-        args += ["-U", settings.DATABASE_USER]
-    if settings.DATABASE_PASSWORD:
-        args += ["-W"]
-    if settings.DATABASE_HOST:
-        args.extend(["-h", settings.DATABASE_HOST])
-    if settings.DATABASE_PORT:
-        args.extend(["-p", str(settings.DATABASE_PORT)])
-    args += [settings.DATABASE_NAME]
-    os.execvp('psql', args)
+class DatabaseClient(BaseDatabaseClient):
+    def runshell(self):
+        args = ['psql']
+        if settings.DATABASE_USER:
+            args += ["-U", settings.DATABASE_USER]
+        if settings.DATABASE_PASSWORD:
+            args += ["-W"]
+        if settings.DATABASE_HOST:
+            args.extend(["-h", settings.DATABASE_HOST])
+        if settings.DATABASE_PORT:
+            args.extend(["-p", str(settings.DATABASE_PORT)])
+        args += [settings.DATABASE_NAME]
+        os.execvp('psql', args)
diff --git a/django/db/backends/postgresql/creation.py b/django/db/backends/postgresql/creation.py
index a8877a7d9b..3e537e345e 100644
--- a/django/db/backends/postgresql/creation.py
+++ b/django/db/backends/postgresql/creation.py
@@ -1,28 +1,38 @@
-# This dictionary maps Field objects to their associated PostgreSQL column
-# types, as strings. Column-type strings can contain format strings; they'll
-# be interpolated against the values of Field.__dict__ before being output.
-# If a column type is set to None, it won't be included in the output.
-DATA_TYPES = {
-    'AutoField':         'serial',
-    'BooleanField':      'boolean',
-    'CharField':         'varchar(%(max_length)s)',
-    'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
-    'DateField':         'date',
-    'DateTimeField':     'timestamp with time zone',
-    'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
-    'FileField':         'varchar(%(max_length)s)',
-    'FilePathField':     'varchar(%(max_length)s)',
-    'FloatField':        'double precision',
-    'IntegerField':      'integer',
-    'IPAddressField':    'inet',
-    'NullBooleanField':  'boolean',
-    'OneToOneField':     'integer',
-    'PhoneNumberField':  'varchar(20)',
-    'PositiveIntegerField': 'integer CHECK ("%(column)s" >= 0)',
-    'PositiveSmallIntegerField': 'smallint CHECK ("%(column)s" >= 0)',
-    'SlugField':         'varchar(%(max_length)s)',
-    'SmallIntegerField': 'smallint',
-    'TextField':         'text',
-    'TimeField':         'time',
-    'USStateField':      'varchar(2)',
-}
+from django.conf import settings
+from django.db.backends.creation import BaseDatabaseCreation
+
+class DatabaseCreation(BaseDatabaseCreation):
+    # This dictionary maps Field objects to their associated PostgreSQL column
+    # types, as strings. Column-type strings can contain format strings; they'll
+    # be interpolated against the values of Field.__dict__ before being output.
+    # If a column type is set to None, it won't be included in the output.
+    data_types = {
+        'AutoField':         'serial',
+        'BooleanField':      'boolean',
+        'CharField':         'varchar(%(max_length)s)',
+        'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
+        'DateField':         'date',
+        'DateTimeField':     'timestamp with time zone',
+        'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
+        'FileField':         'varchar(%(max_length)s)',
+        'FilePathField':     'varchar(%(max_length)s)',
+        'FloatField':        'double precision',
+        'IntegerField':      'integer',
+        'IPAddressField':    'inet',
+        'NullBooleanField':  'boolean',
+        'OneToOneField':     'integer',
+        'PhoneNumberField':  'varchar(20)',
+        'PositiveIntegerField': 'integer CHECK ("%(column)s" >= 0)',
+        'PositiveSmallIntegerField': 'smallint CHECK ("%(column)s" >= 0)',
+        'SlugField':         'varchar(%(max_length)s)',
+        'SmallIntegerField': 'smallint',
+        'TextField':         'text',
+        'TimeField':         'time',
+        'USStateField':      'varchar(2)',
+    }
+
+    def sql_table_creation_suffix(self):
+        assert settings.TEST_DATABASE_COLLATION is None, "PostgreSQL does not support collation setting at database creation time."
+        if settings.TEST_DATABASE_CHARSET:
+            return "WITH ENCODING '%s'" % settings.TEST_DATABASE_CHARSET
+        return ''
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
index 982c004569..7b3ab3bb8a 100644
--- a/django/db/backends/postgresql/introspection.py
+++ b/django/db/backends/postgresql/introspection.py
@@ -1,86 +1,86 @@
-from django.db.backends.postgresql.base import DatabaseOperations
+from django.db.backends import BaseDatabaseIntrospection
 
-quote_name = DatabaseOperations().quote_name
+class DatabaseIntrospection(BaseDatabaseIntrospection):
+    # Maps type codes to Django Field types.
+    data_types_reverse = {
+        16: 'BooleanField',
+        21: 'SmallIntegerField',
+        23: 'IntegerField',
+        25: 'TextField',
+        701: 'FloatField',
+        869: 'IPAddressField',
+        1043: 'CharField',
+        1082: 'DateField',
+        1083: 'TimeField',
+        1114: 'DateTimeField',
+        1184: 'DateTimeField',
+        1266: 'TimeField',
+        1700: 'DecimalField',
+    }
+        
+    def get_table_list(self, cursor):
+        "Returns a list of table names in the current database."
+        cursor.execute("""
+            SELECT c.relname
+            FROM pg_catalog.pg_class c
+            LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+            WHERE c.relkind IN ('r', 'v', '')
+                AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
+                AND pg_catalog.pg_table_is_visible(c.oid)""")
+        return [row[0] for row in cursor.fetchall()]
 
-def get_table_list(cursor):
-    "Returns a list of table names in the current database."
-    cursor.execute("""
-        SELECT c.relname
-        FROM pg_catalog.pg_class c
-        LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
-        WHERE c.relkind IN ('r', 'v', '')
-            AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
-            AND pg_catalog.pg_table_is_visible(c.oid)""")
-    return [row[0] for row in cursor.fetchall()]
+    def get_table_description(self, cursor, table_name):
+        "Returns a description of the table, with the DB-API cursor.description interface."
+        cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name))
+        return cursor.description
 
-def get_table_description(cursor, table_name):
-    "Returns a description of the table, with the DB-API cursor.description interface."
-    cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name))
-    return cursor.description
+    def get_relations(self, cursor, table_name):
+        """
+        Returns a dictionary of {field_index: (field_index_other_table, other_table)}
+        representing all relationships to the given table. Indexes are 0-based.
+        """
+        cursor.execute("""
+            SELECT con.conkey, con.confkey, c2.relname
+            FROM pg_constraint con, pg_class c1, pg_class c2
+            WHERE c1.oid = con.conrelid
+                AND c2.oid = con.confrelid
+                AND c1.relname = %s
+                AND con.contype = 'f'""", [table_name])
+        relations = {}
+        for row in cursor.fetchall():
+            try:
+                # row[0] and row[1] are like "{2}", so strip the curly braces.
+                relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2])
+            except ValueError:
+                continue
+        return relations
 
-def get_relations(cursor, table_name):
-    """
-    Returns a dictionary of {field_index: (field_index_other_table, other_table)}
-    representing all relationships to the given table. Indexes are 0-based.
-    """
-    cursor.execute("""
-        SELECT con.conkey, con.confkey, c2.relname
-        FROM pg_constraint con, pg_class c1, pg_class c2
-        WHERE c1.oid = con.conrelid
-            AND c2.oid = con.confrelid
-            AND c1.relname = %s
-            AND con.contype = 'f'""", [table_name])
-    relations = {}
-    for row in cursor.fetchall():
-        try:
-            # row[0] and row[1] are like "{2}", so strip the curly braces.
-            relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2])
-        except ValueError:
-            continue
-    return relations
+    def get_indexes(self, cursor, table_name):
+        """
+        Returns a dictionary of fieldname -> infodict for the given table,
+        where each infodict is in the format:
+            {'primary_key': boolean representing whether it's the primary key,
+             'unique': boolean representing whether it's a unique index}
+        """
+        # This query retrieves each index on the given table, including the
+        # first associated field name
+        cursor.execute("""
+            SELECT attr.attname, idx.indkey, idx.indisunique, idx.indisprimary
+            FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
+                pg_catalog.pg_index idx, pg_catalog.pg_attribute attr
+            WHERE c.oid = idx.indrelid
+                AND idx.indexrelid = c2.oid
+                AND attr.attrelid = c.oid
+                AND attr.attnum = idx.indkey[0]
+                AND c.relname = %s""", [table_name])
+        indexes = {}
+        for row in cursor.fetchall():
+            # row[1] (idx.indkey) is stored in the DB as an array. It comes out as
+            # a string of space-separated integers. This designates the field
+            # indexes (1-based) of the fields that have indexes on the table.
+            # Here, we skip any indexes across multiple fields.
+            if ' ' in row[1]:
+                continue
+            indexes[row[0]] = {'primary_key': row[3], 'unique': row[2]}
+        return indexes
 
-def get_indexes(cursor, table_name):
-    """
-    Returns a dictionary of fieldname -> infodict for the given table,
-    where each infodict is in the format:
-        {'primary_key': boolean representing whether it's the primary key,
-         'unique': boolean representing whether it's a unique index}
-    """
-    # This query retrieves each index on the given table, including the
-    # first associated field name
-    cursor.execute("""
-        SELECT attr.attname, idx.indkey, idx.indisunique, idx.indisprimary
-        FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
-            pg_catalog.pg_index idx, pg_catalog.pg_attribute attr
-        WHERE c.oid = idx.indrelid
-            AND idx.indexrelid = c2.oid
-            AND attr.attrelid = c.oid
-            AND attr.attnum = idx.indkey[0]
-            AND c.relname = %s""", [table_name])
-    indexes = {}
-    for row in cursor.fetchall():
-        # row[1] (idx.indkey) is stored in the DB as an array. It comes out as
-        # a string of space-separated integers. This designates the field
-        # indexes (1-based) of the fields that have indexes on the table.
-        # Here, we skip any indexes across multiple fields.
-        if ' ' in row[1]:
-            continue
-        indexes[row[0]] = {'primary_key': row[3], 'unique': row[2]}
-    return indexes
-
-# Maps type codes to Django Field types.
-DATA_TYPES_REVERSE = {
-    16: 'BooleanField',
-    21: 'SmallIntegerField',
-    23: 'IntegerField',
-    25: 'TextField',
-    701: 'FloatField',
-    869: 'IPAddressField',
-    1043: 'CharField',
-    1082: 'DateField',
-    1083: 'TimeField',
-    1114: 'DateTimeField',
-    1184: 'DateTimeField',
-    1266: 'TimeField',
-    1700: 'DecimalField',
-}