from __future__ import print_function import os.path import sys import re import warnings import cx_Oracle from django.db import connection, models from django.db.backends.util import truncate_name from django.core.management.color import no_style from django.db.models.fields import NOT_PROVIDED from django.db.utils import DatabaseError # In revision r16016 function get_sequence_name has been transformed into # method of DatabaseOperations class. To make code backward-compatible we # need to handle both situations. try: from django.db.backends.oracle.base import get_sequence_name\ as original_get_sequence_name except ImportError: original_get_sequence_name = None from south.db import generic class DatabaseOperations(generic.DatabaseOperations): """ Oracle implementation of database operations. """ backend_name = 'oracle' alter_string_set_type = 'ALTER TABLE %(table_name)s MODIFY %(column)s %(type)s %(nullity)s;' alter_string_set_default = 'ALTER TABLE %(table_name)s MODIFY %(column)s DEFAULT %(default)s;' alter_string_update_nulls_to_default = \ 'UPDATE %(table_name)s SET %(column)s = %(default)s WHERE %(column)s IS NULL;' add_column_string = 'ALTER TABLE %s ADD %s;' delete_column_string = 'ALTER TABLE %s DROP COLUMN %s;' add_constraint_string = 'ALTER TABLE %(table_name)s ADD CONSTRAINT %(constraint)s %(clause)s' allows_combined_alters = False has_booleans = False constraints_dict = { 'P': 'PRIMARY KEY', 'U': 'UNIQUE', 'C': 'CHECK', 'R': 'FOREIGN KEY' } def get_sequence_name(self, table_name): if original_get_sequence_name is None: return self._get_connection().ops._get_sequence_name(table_name) else: return original_get_sequence_name(table_name) #TODO: This will cause very obscure bugs if anyone uses a column name or string value # that looks like a column definition (with 'CHECK', 'DEFAULT' and/or 'NULL' in it) # e.g. "CHECK MATE" varchar(10) DEFAULT 'NULL' def adj_column_sql(self, col): # Syntax fixes -- Oracle is picky about clause order col = re.sub('(?PCHECK \(.*\))(?P.*)(?PDEFAULT \d+)', lambda mo: '%s %s%s'%(mo.group('default'), mo.group('constr'), mo.group('any')), col) #syntax fix for boolean/integer field only col = re.sub('(?P(NOT )?NULL) (?P(.* )?)(?PDEFAULT.+)', lambda mo: '%s %s %s'%(mo.group('default'),mo.group('not_null'),mo.group('misc') or ''), col) #fix order of NULL/NOT NULL and DEFAULT return col def check_meta(self, table_name): return table_name in [ m._meta.db_table for m in models.get_models() ] #caching provided by Django def normalize_name(self, name): """ Get the properly shortened and uppercased identifier as returned by quote_name(), but without the actual quotes. """ nn = self.quote_name(name) if nn[0] == '"' and nn[-1] == '"': nn = nn[1:-1] return nn @generic.invalidate_table_constraints def create_table(self, table_name, fields): qn = self.quote_name(table_name) columns = [] autoinc_sql = '' for field_name, field in fields: field = self._field_sanity(field) # avoid default values in CREATE TABLE statements (#925) field._suppress_default = True col = self.column_sql(table_name, field_name, field) if not col: continue col = self.adj_column_sql(col) columns.append(col) if isinstance(field, models.AutoField): autoinc_sql = connection.ops.autoinc_sql(table_name, field_name) sql = 'CREATE TABLE %s (%s);' % (qn, ', '.join([col for col in columns])) self.execute(sql) if autoinc_sql: self.execute(autoinc_sql[0]) self.execute(autoinc_sql[1]) @generic.invalidate_table_constraints def delete_table(self, table_name, cascade=True): qn = self.quote_name(table_name) # Note: PURGE is not valid syntax for Oracle 9i (it was added in 10) if cascade: self.execute('DROP TABLE %s CASCADE CONSTRAINTS;' % qn) else: self.execute('DROP TABLE %s;' % qn) # If the table has an AutoField a sequence was created. sequence_sql = """ DECLARE i INTEGER; BEGIN SELECT COUNT(*) INTO i FROM USER_CATALOG WHERE TABLE_NAME = '%(sq_name)s' AND TABLE_TYPE = 'SEQUENCE'; IF i = 1 THEN EXECUTE IMMEDIATE 'DROP SEQUENCE "%(sq_name)s"'; END IF; END; /""" % {'sq_name': self.get_sequence_name(table_name)} self.execute(sequence_sql) @generic.invalidate_table_constraints def alter_column(self, table_name, name, field, explicit_name=True, ignore_constraints=False): if self.dry_run: if self.debug: print(' - no dry run output for alter_column() due to dynamic DDL, sorry') return qn = self.quote_name(table_name) # hook for the field to do any resolution prior to it's attributes being queried if hasattr(field, 'south_init'): field.south_init() field = self._field_sanity(field) # Add _id or whatever if we need to field.set_attributes_from_name(name) if not explicit_name: name = field.column qn_col = self.quote_name(name) # First, change the type # This will actually also add any CHECK constraints needed, # since e.g. 'type' for a BooleanField is 'NUMBER(1) CHECK (%(qn_column)s IN (0,1))' params = { 'table_name':qn, 'column': qn_col, 'type': self._db_type_for_alter_column(field), 'nullity': 'NOT NULL', 'default': 'NULL' } if field.null: params['nullity'] = 'NULL' sql_templates = [ (self.alter_string_set_type, params, []), (self.alter_string_set_default, params, []), ] if not field.null and field.has_default(): # Use default for rows that had nulls. To support the case where # the new default does not fit the old type, we need to first change # the column type to the new type, but null=True; then set the default; # then complete the type change. def change_params(**kw): "A little helper for non-destructively changing the params" p = params.copy() p.update(kw) return p sql_templates[:0] = [ (self.alter_string_set_type, change_params(nullity='NULL'),[]), (self.alter_string_update_nulls_to_default, change_params(default="%s"), [field.get_default()]), ] if not ignore_constraints: # drop CHECK constraints. Make sure this is executed before the ALTER TABLE statements # generated above, since those statements recreate the constraints we delete here. check_constraints = self._constraints_affecting_columns(table_name, [name], "CHECK") for constraint in check_constraints: self.execute(self.delete_check_sql % { 'table': self.quote_name(table_name), 'constraint': self.quote_name(constraint), }) # Drop foreign constraints try: self.delete_foreign_key(qn, qn_col) except ValueError: # There weren't any pass for sql_template, params, args in sql_templates: try: self.execute(sql_template % params, args, print_all_errors=False) except DatabaseError as exc: description = str(exc) # Oracle complains if a column is already NULL/NOT NULL if 'ORA-01442' in description or 'ORA-01451' in description: # so we just drop NULL/NOT NULL part from target sql and retry params['nullity'] = '' sql = sql_template % params self.execute(sql) # Oracle also has issues if we try to change a regular column # to a LOB or vice versa (also REF, object, VARRAY or nested # table, but these don't come up much in Django apps) elif 'ORA-22858' in description or 'ORA-22859' in description: self._alter_column_lob_workaround(table_name, name, field) else: self._print_sql_error(exc, sql_template % params) raise if not ignore_constraints: # Add back FK constraints if needed if field.rel: #and self.supports_foreign_keys: self.add_deferred_sql( self.foreign_key_sql( qn[1:-1], # foreign_key_sql uses this as part of constraint name qn_col[1:-1], # foreign_key_sql uses this as part of constraint name field.rel.to._meta.db_table, field.rel.to._meta.get_field(field.rel.field_name).column ) ) def _alter_column_lob_workaround(self, table_name, name, field): """ Oracle refuses to change a column type from/to LOB to/from a regular column. In Django, this shows up when the field is changed from/to a TextField. What we need to do instead is: - Rename the original column - Add the desired field as new - Update the table to transfer values from old to new - Drop old column """ renamed = self._generate_temp_name(name) self.rename_column(table_name, name, renamed) self.add_column(table_name, name, field, keep_default=False) self.execute("UPDATE %s set %s=%s" % ( self.quote_name(table_name), self.quote_name(name), self.quote_name(renamed), )) self.delete_column(table_name, renamed) def _generate_temp_name(self, for_name): suffix = hex(hash(for_name)).upper()[1:] return self.normalize_name(for_name + "_" + suffix) @generic.copy_column_constraints #TODO: Appears to be nulled by the delete decorator below... @generic.delete_column_constraints def rename_column(self, table_name, old, new): if old == new: # Short-circuit out return [] self.execute('ALTER TABLE %s RENAME COLUMN %s TO %s;' % ( self.quote_name(table_name), self.quote_name(old), self.quote_name(new), )) @generic.invalidate_table_constraints def add_column(self, table_name, name, field, keep_default=False): field = self._field_sanity(field) sql = self.column_sql(table_name, name, field) sql = self.adj_column_sql(sql) if sql: params = ( self.quote_name(table_name), sql ) sql = self.add_column_string % params self.execute(sql) # Now, drop the default if we need to if field.default is not None: field.default = NOT_PROVIDED self.alter_column(table_name, name, field, explicit_name=False, ignore_constraints=True) def delete_column(self, table_name, name): return super(DatabaseOperations, self).delete_column(self.quote_name(table_name), name) def lookup_constraint(self, db_name, table_name, column_name=None): if column_name: # Column names in the constraint cache come from the database, # make sure we use the properly shortened/uppercased version # for lookup. column_name = self.normalize_name(column_name) return super(DatabaseOperations, self).lookup_constraint(db_name, table_name, column_name) def _constraints_affecting_columns(self, table_name, columns, type="UNIQUE"): if columns: columns = [self.normalize_name(c) for c in columns] return super(DatabaseOperations, self)._constraints_affecting_columns(table_name, columns, type) def _field_sanity(self, field): """ This particular override stops us sending DEFAULTs for BooleanField. """ if isinstance(field, models.BooleanField) and field.has_default(): field.default = int(field.to_python(field.get_default())) # On Oracle, empty strings are null if isinstance(field, (models.CharField, models.TextField)): field.null = field.empty_strings_allowed return field def _default_value_workaround(self, value): from datetime import date,time,datetime if isinstance(value, (date,time,datetime)): return "'%s'" % value else: return super(DatabaseOperations, self)._default_value_workaround(value) def _fill_constraint_cache(self, db_name, table_name): self._constraint_cache.setdefault(db_name, {}) self._constraint_cache[db_name][table_name] = {} rows = self.execute(""" SELECT user_cons_columns.constraint_name, user_cons_columns.column_name, user_constraints.constraint_type FROM user_constraints JOIN user_cons_columns ON user_constraints.table_name = user_cons_columns.table_name AND user_constraints.constraint_name = user_cons_columns.constraint_name WHERE user_constraints.table_name = '%s' """ % self.normalize_name(table_name)) for constraint, column, kind in rows: self._constraint_cache[db_name][table_name].setdefault(column, set()) self._constraint_cache[db_name][table_name][column].add((self.constraints_dict[kind], constraint)) return