schema-evolution:

added new "pk_requires_unique" option to the backend, because sqlite3 requires "UNIQUE" when creating PKs in order to 
_actually_ create the constraint.
fixed "get_known_column_flags" introspection for sqlite3
implemented "get_drop_column_sql" for sqlite3 to work around sqlite's lack of DROP COLUMN support
added partial of the sqlite3 unit tests



git-svn-id: http://code.djangoproject.com/svn/django/branches/schema-evolution@5785 bcc190cf-cafb-0310-a4f2-bffc1f526a37

11 files changed, 135 insertions, 37 deletions

diff --git a/django/core/management.py b/django/core/management.py
index 64857d52e5..815c7a571b 100644
--- a/django/core/management.py
+++ b/django/core/management.py
@@ -170,7 +170,7 @@ def _get_sql_model_create(model, known_models=set()):
         field_output = [style.SQL_FIELD(backend.quote_name(f.column)),
             style.SQL_COLTYPE(col_type)]
         field_output.append(style.SQL_KEYWORD('%sNULL' % (not f.null and 'NOT ' or '')))
-        if f.unique and (not f.primary_key or backend.allows_unique_and_pk):
+        if (f.unique and (not f.primary_key or backend.allows_unique_and_pk)) or (f.primary_key and backend.pk_requires_unique):
             field_output.append(style.SQL_KEYWORD('UNIQUE'))
         if f.primary_key:
             field_output.append(style.SQL_KEYWORD('PRIMARY KEY'))
@@ -569,18 +569,6 @@ def get_sql_evolution_check_for_new_fields(klass, new_table_name):
             data_type = f.get_internal_type()
             col_type = data_types[data_type]
             if col_type is not None:
-#                field_output = []
-#                field_output.append('ALTER TABLE')
-#                field_output.append(db_table)
-#                field_output.append('ADD COLUMN')
-#                field_output.append(backend.quote_name(f.column))
-#                field_output.append(style.SQL_COLTYPE(col_type % rel_field.__dict__))
-#                field_output.append(style.SQL_KEYWORD('%sNULL' % (not f.null and 'NOT ' or '')))
-#                if f.unique:
-#                    field_output.append(style.SQL_KEYWORD('UNIQUE'))
-#                if f.primary_key:
-#                    field_output.append(style.SQL_KEYWORD('PRIMARY KEY'))
-#                output.append(' '.join(field_output) + ';')
                 output.append( backend.get_add_column_sql( db_table, f.column, style.SQL_COLTYPE(col_type % rel_field.__dict__), f.null, f.unique, f.primary_key ) )
     return output
 
@@ -664,7 +652,7 @@ def get_sql_evolution_check_for_changed_field_flags(klass, new_table_name):
                     ( column_flags['unique']!=f.unique and ( settings.DATABASE_ENGINE!='postgresql' or not f.primary_key ) ) or \
                     column_flags['primary_key']!=f.primary_key:
                     #column_flags['foreign_key']!=f.foreign_key:
-#                print 
+#                print 'need to change'
 #                print db_table, f.column, column_flags
 #                print "column_flags['allow_null']!=f.null", column_flags['allow_null']!=f.null
 #                print "not f.primary_key and isinstance(f, CharField) and column_flags['maxlength']!=str(f.maxlength)", not f.primary_key and isinstance(f, CharField) and column_flags['maxlength']!=str(f.maxlength)
@@ -703,9 +691,9 @@ def get_sql_evolution_check_for_dead_fields(klass, new_table_name):
         suspect_fields.discard(f.aka)
         if f.aka: suspect_fields.difference_update(f.aka)
     if len(suspect_fields)>0:
-        output.append( '-- warning: as the following may cause data loss, it/they must be run manually' )
+        output.append( '-- warning: the following may cause data loss' )
         for suspect_field in suspect_fields:
-            output.append( '-- '+ backend.get_drop_column_sql( db_table, suspect_field ) )
+            output.extend( backend.get_drop_column_sql( db_table, suspect_field ) )
         output.append( '-- end warning' )
     return output
 
diff --git a/django/db/backends/ado_mssql/base.py b/django/db/backends/ado_mssql/base.py
index 0deb6aae64..5ed192114b 100644
--- a/django/db/backends/ado_mssql/base.py
+++ b/django/db/backends/ado_mssql/base.py
@@ -91,6 +91,7 @@ class DatabaseWrapper(local):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = False
 autoindexes_primary_keys = True
 needs_datetime_string_cast = True
 needs_upper_for_iops = False
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 6e9a5f0e46..ebe0c312aa 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -136,6 +136,7 @@ class DatabaseWrapper(local):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = False
 autoindexes_primary_keys = False
 needs_datetime_string_cast = True     # MySQLdb requires a typecast for dates
 needs_upper_for_iops = False
@@ -284,7 +285,7 @@ def get_add_column_sql( table_name, col_name, col_type, null, unique, primary_ke
 def get_drop_column_sql( table_name, col_name ):
     output = []
     output.append( 'ALTER TABLE '+ quote_name(table_name) +' DROP COLUMN '+ quote_name(col_name) + ';' )
-    return '\n'.join(output)
+    return output
     
     
 OPERATOR_MAPPING = {
diff --git a/django/db/backends/mysql_old/base.py b/django/db/backends/mysql_old/base.py
index 0116af53ea..274d27a0be 100644
--- a/django/db/backends/mysql_old/base.py
+++ b/django/db/backends/mysql_old/base.py
@@ -151,6 +151,7 @@ class DatabaseWrapper(local):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = False
 autoindexes_primary_keys = False
 needs_datetime_string_cast = True     # MySQLdb requires a typecast for dates
 needs_upper_for_iops = False
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 0cf8967c7a..7984c13d69 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -117,6 +117,7 @@ class DatabaseWrapper(local):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = False
 autoindexes_primary_keys = True
 needs_datetime_string_cast = True
 needs_upper_for_iops = False
@@ -321,7 +322,7 @@ def get_add_column_sql( table_name, col_name, col_type, null, unique, primary_ke
 def get_drop_column_sql( table_name, col_name ):
     output = []
     output.append( 'ALTER TABLE '+ quote_name(table_name) +' DROP COLUMN '+ quote_name(col_name) + ';' )
-    return '\n'.join(output)
+    return output
 
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
index 602239277a..bbeee184e0 100644
--- a/django/db/backends/postgresql/introspection.py
+++ b/django/db/backends/postgresql/introspection.py
@@ -81,8 +81,8 @@ def get_known_column_flags( cursor, table_name, column_name ):
     dict['foreign_key'] = False
     dict['unique'] = False
     dict['default'] = ''
-            
-#    dict['allow_null'] = False
+    dict['allow_null'] = False
+
     for row in cursor.fetchall():
         if row[0] == column_name:
 
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index c0ecbf80e9..e1687baae8 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -79,6 +79,7 @@ class DatabaseWrapper(local):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = False
 autoindexes_primary_keys = True
 needs_datetime_string_cast = False
 needs_upper_for_iops = False
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 67c56daada..1670c3bc37 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -2,6 +2,7 @@
 SQLite3 backend for django.  Requires pysqlite2 (http://pysqlite.org/).
 """
 
+from django.core import management
 from django.db.backends import util
 try:
     try:
@@ -102,6 +103,7 @@ class SQLiteCursorWrapper(Database.Cursor):
 
 allows_group_by_ordinal = True
 allows_unique_and_pk = True
+pk_requires_unique = True # or else the constraint is never created
 autoindexes_primary_keys = True
 needs_datetime_string_cast = True
 needs_upper_for_iops = False
@@ -227,13 +229,16 @@ def get_change_column_name_sql( table_name, indexes, old_col_name, new_col_name,
     output.append( 'ALTER TABLE '+ quote_name(table_name) +' ADD COLUMN '+ quote_name(new_col_name) +' '+ col_def + ';' )
     output.append( 'UPDATE '+ quote_name(table_name) +' SET '+ new_col_name +' = '+ old_col_name +' WHERE '+ pk_name +'=(select '+ pk_name +' from '+ table_name +');' )
     output.append( '-- FYI: sqlite does not support deleting columns, so  '+ quote_name(old_col_name) +' remains as cruft' )
-    # use the following when sqlite gets drop support
-    #output.append( 'ALTER TABLE '+ quote_name(table_name) +' DROP COLUMN '+ quote_name(old_col_name) )
     return '\n'.join(output)
 
-def get_change_column_def_sql( table_name, col_name, col_def ):
+def get_change_column_def_sql( table_name, col_name, col_type, null, unique, primary_key ):
     # sqlite doesn't support column modifications, so we fake it
     output = []
+    col_def = col_type +' '+ ('%sNULL' % (not null and 'NOT ' or ''))
+    if unique or primary_key:
+        col_def += ' '+ 'UNIQUE'
+    if primary_key:
+        col_def += ' '+ 'PRIMARY KEY'
     # TODO: fake via renaming the table, building a new one and deleting the old
     output.append('-- sqlite does not support column modifications '+ quote_name(table_name) +'.'+ quote_name(col_name) +' to '+ col_def)
     return '\n'.join(output)
@@ -247,7 +252,7 @@ def get_add_column_sql( table_name, col_name, col_type, null, unique, primary_ke
     field_output.append(quote_name(col_name))
     field_output.append(col_type)
     field_output.append(('%sNULL' % (not null and 'NOT ' or '')))
-    if unique:
+    if unique or primary_key:
         field_output.append(('UNIQUE'))
     if primary_key:
         field_output.append(('PRIMARY KEY'))
@@ -255,11 +260,28 @@ def get_add_column_sql( table_name, col_name, col_type, null, unique, primary_ke
     return '\n'.join(output)
 
 def get_drop_column_sql( table_name, col_name ):
+    model = get_model_from_table_name(table_name)
     output = []
-    output.append( '-- FYI: sqlite does not support deleting columns, so  '+ quote_name(old_col_name) +' remains as cruft' )
-    # use the following when sqlite gets drop support
-    # output.append( '-- ALTER TABLE '+ quote_name(table_name) +' DROP COLUMN '+ quote_name(col_name) )
-    return '\n'.join(output)
+    output.append( '-- FYI: sqlite does not support deleting columns, so we create a new '+ quote_name(col_name) +' and delete the old  (ie, this could take a while)' )
+    tmp_table_name = table_name + '_1337_TMP' # unlikely to produce a namespace conflict
+    output.append( get_change_table_name_sql( tmp_table_name, table_name ) )
+    output.extend( management._get_sql_model_create(model, set())[0] )
+    new_cols = []
+    for f in model._meta.fields:
+        new_cols.append( quote_name(f.column) )
+    output.append( 'INSERT INTO '+ quote_name(table_name) +' SELECT '+ ','.join(new_cols) +' FROM '+ quote_name(tmp_table_name) +';' )
+    output.append( 'DROP TABLE '+ quote_name(tmp_table_name) +';' )
+    return output
+
+def get_model_from_table_name(table_name):
+    from django.db import models
+    for app in models.get_apps():
+        app_name = app.__name__.split('.')[-2]
+        if app_name == table_name.split('_')[0] or app_name == '_'.join(table_name.split('_')[0:1]) or app_name == '_'.join(table_name.split('_')[0:2]):
+            for model in models.get_models(app):
+                if model._meta.db_table == table_name:
+                    return model
+    return None
     
 
 # SQLite requires LIKE statements to include an ESCAPE clause if the value
diff --git a/django/db/backends/sqlite3/introspection.py b/django/db/backends/sqlite3/introspection.py
index ce033757c9..b59ba70312 100644
--- a/django/db/backends/sqlite3/introspection.py
+++ b/django/db/backends/sqlite3/introspection.py
@@ -53,17 +53,38 @@ def get_columns(cursor, table_name):
 def get_known_column_flags( cursor, table_name, column_name ):
     cursor.execute("PRAGMA table_info(%s)" % quote_name(table_name))
     dict = {}
+    dict['primary_key'] = False
+    dict['foreign_key'] = False
+    dict['unique'] = False
+    dict['default'] = ''
+    dict['allow_null'] = True
+
     for row in cursor.fetchall():
+#        print row
         if row[1] == column_name:
+            col_type = row[2]
 
             # maxlength check goes here
             if row[2][0:7]=='varchar':
                 dict['maxlength'] = row[2][8:len(row[2])-1]
             
             # default flag check goes here
-            #if row[2]=='YES': dict['allow_null'] = True
-            #else: dict['allow_null'] = False
+            dict['allow_null'] = row[3]==0
             
+            # default value check goes here
+            dict['default'] = row[4]
+
+    cursor.execute("PRAGMA index_list(%s)" % quote_name(table_name))
+    index_names = []
+    for row in cursor.fetchall():
+        index_names.append(row[1])
+    for index_name in index_names:
+        cursor.execute("PRAGMA index_info(%s)" % quote_name(index_name))
+        for row in cursor.fetchall():
+            if row[2]==column_name:
+                if col_type=='integer': dict['primary_key'] = True  # sqlite3 does not distinguish between unique and pk; all 
+                else: dict['unique'] = True                         # unique integer columns are treated as part of the pk.
+
             # primary/foreign/unique key flag check goes here
             #if row[3]=='PRI': dict['primary_key'] = True
             #else: dict['primary_key'] = False
@@ -72,12 +93,8 @@ def get_known_column_flags( cursor, table_name, column_name ):
             #if row[3]=='UNI': dict['unique'] = True
             #else: dict['unique'] = False
             
-            # default value check goes here
-            # if row[4]=='NULL': dict['default'] = None
-            # else: dict['default'] = row[4]
-            #dict['default'] = row[4]
-            
-    print table_name, column_name, dict
+
+#    print dict
     return dict
     
 def _table_info(cursor, name):
diff --git a/django/test/simple.py b/django/test/simple.py
index 9730a0df1d..e2d2359569 100644
--- a/django/test/simple.py
+++ b/django/test/simple.py
@@ -98,4 +98,4 @@ def run_tests(module_list, verbosity=1, extra_tests=[]):
     teardown_test_environment()
     
     return len(result.failures) + len(result.errors)
-    
\ No newline at end of file
+    
diff --git a/tests/modeltests/schema_evolution/models.py b/tests/modeltests/schema_evolution/models.py
index b401881714..7f9e59c255 100644
--- a/tests/modeltests/schema_evolution/models.py
+++ b/tests/modeltests/schema_evolution/models.py
@@ -141,3 +141,69 @@ if settings.DATABASE_ENGINE == 'postgresql':
 
 """
 
+if settings.DATABASE_ENGINE == 'sqlite3':
+    __test__['API_TESTS'] += """
+# the table as it is supposed to be
+>>> create_table_sql = management.get_sql_all(app)
+>>> print create_table_sql
+['CREATE TABLE "schema_evolution_person" (\\n    "id" integer NOT NULL UNIQUE PRIMARY KEY,\\n    "name" varchar(20) NOT NULL,\\n    "gender" varchar(1) NOT NULL,\\n    "gender2" varchar(1) NOT NULL\\n)\\n;']
+
+# make sure we don't evolve an unedited table
+>>> management.get_sql_evolution(app)
+[]
+
+# delete a column, so it looks like we've recently added a field
+>>> cursor.execute( 'DROP TABLE "schema_evolution_person";' ).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> cursor.execute( 'CREATE TABLE "schema_evolution_person" ( "id" integer NOT NULL UNIQUE PRIMARY KEY, "name" varchar(20) NOT NULL, "gender" varchar(1) NOT NULL );' ).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> management.get_sql_evolution(app)
+['ALTER TABLE "schema_evolution_person" ADD COLUMN "gender2" varchar(1) NOT NULL;']
+
+# reset the db
+>>> cursor.execute('DROP TABLE schema_evolution_person;').__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> cursor.execute(create_table_sql[0]).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+
+# add a column, so it looks like we've recently deleted a field
+>>> cursor.execute( 'DROP TABLE "schema_evolution_person";' ).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> cursor.execute( 'CREATE TABLE "schema_evolution_person" ( "id" integer NOT NULL UNIQUE PRIMARY KEY, "name" varchar(20) NOT NULL, "gender" varchar(1) NOT NULL, "gender2" varchar(1) NOT NULL, "gender_new" varchar(1) NOT NULL );' ).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> management.get_sql_evolution(app)
+['-- warning: the following may cause data loss', u'-- FYI: sqlite does not support deleting columns, so we create a new "gender_new" and delete the old  (ie, this could take a while)', 'ALTER TABLE "schema_evolution_person" RENAME TO "schema_evolution_person_1337_TMP";', 'CREATE TABLE "schema_evolution_person" (\\n    "id" integer NOT NULL UNIQUE PRIMARY KEY,\\n    "name" varchar(20) NOT NULL,\\n    "gender" varchar(1) NOT NULL,\\n    "gender2" varchar(1) NOT NULL\\n)\\n;', 'INSERT INTO "schema_evolution_person" SELECT "id","name","gender","gender2" FROM "schema_evolution_person_1337_TMP";', 'DROP TABLE "schema_evolution_person_1337_TMP";', '-- end warning']
+
+# reset the db
+>>> cursor.execute('DROP TABLE schema_evolution_person;').__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+>>> cursor.execute(create_table_sql[0]).__class__
+<class 'django.db.backends.sqlite3.base.SQLiteCursorWrapper'>
+
+"""
+
+crap = """
+
+# rename column, so it looks like we've recently renamed a field
+>>> cursor.execute( backend.get_change_column_name_sql( 'schema_evolution_person', {}, 'gender2', 'gender_old', 'varchar(1)' ) )
+>>> management.get_sql_evolution(app)
+['ALTER TABLE "schema_evolution_person" RENAME COLUMN "gender_old" TO "gender2";']
+
+# reset the db
+>>> cursor.execute('DROP TABLE schema_evolution_person;'); cursor.execute(create_table_sql[0])
+
+# rename table, so it looks like we've recently renamed a model
+>>> cursor.execute( backend.get_change_table_name_sql( 'schema_evolution_personold', 'schema_evolution_person' ) )
+>>> management.get_sql_evolution(app)
+['ALTER TABLE "schema_evolution_personold" RENAME TO "schema_evolution_person";']
+
+# reset the db
+>>> cursor.execute(create_table_sql[0])
+
+# change column flags, so it looks like we've recently changed a column flag
+>>> cursor.execute( backend.get_change_column_def_sql( 'schema_evolution_person', 'name', 'varchar(10)', True, False, False ) )
+>>> management.get_sql_evolution(app)
+['ALTER TABLE "schema_evolution_person" ADD COLUMN "name_tmp" varchar(20);\\nUPDATE "schema_evolution_person" SET "name_tmp" = "name";\\nALTER TABLE "schema_evolution_person" DROP COLUMN "name";\\nALTER TABLE "schema_evolution_person" RENAME COLUMN "name_tmp" TO "name";\\nALTER TABLE "schema_evolution_person" ALTER COLUMN "name" SET NOT NULL;']
+
+"""
+