From 3bb0f118ca375f25cd0c03a5733ee2ef9d79dfa5 Mon Sep 17 00:00:00 2001 From: Aymeric Augustin Date: Sat, 26 Apr 2014 10:22:48 +0200 Subject: [1.7.x] Fixed #3214 -- Stopped parsing SQL with regex. Avoided introducing a new regex-based SQL splitter in the migrations framework, before we're bound by backwards compatibility. Adapted this change to the legacy "initial SQL data" feature, even though it's already deprecated, in order to facilitate the transition to migrations. sqlparse becomes mandatory for RunSQL on some databases (all but PostgreSQL). There's no API to provide a single statement and tell Django not to attempt splitting. Since we have a more robust splitting implementation, that seems like a good tradeoff. It's easier to add a new keyword argument later if necessary than to remove one. Many people contributed to both tickets, thank you all, and especially Claude for the review. Refs #22401. Backport of 8b5b199 from master --- django/core/management/sql.py | 5 ++-- django/db/backends/__init__.py | 34 ++++++++++++++++++++++ django/db/backends/postgresql_psycopg2/base.py | 1 + .../db/backends/postgresql_psycopg2/operations.py | 3 ++ django/db/migrations/operations/special.py | 28 +++--------------- 5 files changed, 44 insertions(+), 27 deletions(-) (limited to 'django') diff --git a/django/core/management/sql.py b/django/core/management/sql.py index c789701c47..4832f27b07 100644 --- a/django/core/management/sql.py +++ b/django/core/management/sql.py @@ -155,6 +155,7 @@ def sql_all(app_config, style, connection): def _split_statements(content): + # Private API only called from code that emits a RemovedInDjango19Warning. comment_re = re.compile(r"^((?:'[^']*'|[^'])*?)--.*$") statements = [] statement = [] @@ -202,9 +203,7 @@ def custom_sql_for_model(model, style, connection): for sql_file in sql_files: if os.path.exists(sql_file): with codecs.open(sql_file, 'r' if six.PY3 else 'U', encoding=settings.FILE_CHARSET) as fp: - # Some backends can't execute more than one SQL statement at a time, - # so split into separate statements. - output.extend(_split_statements(fp.read())) + output.extend(connection.ops.prepare_sql_script(fp.read(), _allow_fallback=True)) return output diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py index 10836f4651..4556fddd94 100644 --- a/django/db/backends/__init__.py +++ b/django/db/backends/__init__.py @@ -1,5 +1,6 @@ import datetime import time +import warnings try: from django.utils.six.moves import _thread as thread @@ -16,6 +17,7 @@ from django.db.backends.signals import connection_created from django.db.backends import utils from django.db.transaction import TransactionManagementError from django.db.utils import DatabaseError, DatabaseErrorWrapper, ProgrammingError +from django.utils.deprecation import RemovedInDjango19Warning from django.utils.functional import cached_property from django.utils import six from django.utils import timezone @@ -697,6 +699,10 @@ class BaseDatabaseFeatures(object): # Does 'a' LIKE 'A' match? has_case_insensitive_like = True + # Does the backend require the sqlparse library for splitting multi-line + # statements before executing them? + requires_sqlparse_for_splitting = True + def __init__(self, connection): self.connection = connection @@ -972,6 +978,34 @@ class BaseDatabaseOperations(object): """ return 'DEFAULT' + def prepare_sql_script(self, sql, _allow_fallback=False): + """ + Takes a SQL script that may contain multiple lines and returns a list + of statements to feed to successive cursor.execute() calls. + + Since few databases are able to process raw SQL scripts in a single + cursor.execute() call and PEP 249 doesn't talk about this use case, + the default implementation is conservative. + """ + # Remove _allow_fallback and keep only 'return ...' in Django 1.9. + try: + # This import must stay inside the method because it's optional. + import sqlparse + except ImportError: + if _allow_fallback: + # Without sqlparse, fall back to the legacy (and buggy) logic. + warnings.warn( + "Providing intial SQL data on a %s database will require " + "sqlparse in Django 1.9." % self.connection.vendor, + RemovedInDjango19Warning) + from django.core.management.sql import _split_statements + return _split_statements(sql) + else: + raise + else: + return [sqlparse.format(statement, strip_comments=True) + for statement in sqlparse.split(sql) if statement] + def process_clob(self, value): """ Returns the value of a CLOB column, for backends that return a locator diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py index cc44075ba7..91a183e8b5 100644 --- a/django/db/backends/postgresql_psycopg2/base.py +++ b/django/db/backends/postgresql_psycopg2/base.py @@ -59,6 +59,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): nulls_order_largest = True closed_cursor_error_class = InterfaceError has_case_insensitive_like = False + requires_sqlparse_for_splitting = False class DatabaseWrapper(BaseDatabaseWrapper): diff --git a/django/db/backends/postgresql_psycopg2/operations.py b/django/db/backends/postgresql_psycopg2/operations.py index 9285e6eeca..b9d0231768 100644 --- a/django/db/backends/postgresql_psycopg2/operations.py +++ b/django/db/backends/postgresql_psycopg2/operations.py @@ -93,6 +93,9 @@ class DatabaseOperations(BaseDatabaseOperations): def no_limit_value(self): return None + def prepare_sql_script(self, sql, _allow_fallback=False): + return [sql] + def quote_name(self, name): if name.startswith('"') and name.endswith('"'): return name # Quoting once is enough. diff --git a/django/db/migrations/operations/special.py b/django/db/migrations/operations/special.py index 4f0c494f33..f87585f0db 100644 --- a/django/db/migrations/operations/special.py +++ b/django/db/migrations/operations/special.py @@ -1,4 +1,3 @@ -import re from .base import Operation @@ -43,20 +42,16 @@ class SeparateDatabaseAndState(Operation): class RunSQL(Operation): """ - Runs some raw SQL - a single statement by default, but it will attempt - to parse and split it into multiple statements if multiple=True. - - A reverse SQL statement may be provided. + Runs some raw SQL. A reverse SQL statement may be provided. Also accepts a list of operations that represent the state change effected by this SQL change, in case it's custom column/table creation/deletion. """ - def __init__(self, sql, reverse_sql=None, state_operations=None, multiple=False): + def __init__(self, sql, reverse_sql=None, state_operations=None): self.sql = sql self.reverse_sql = reverse_sql self.state_operations = state_operations or [] - self.multiple = multiple @property def reversible(self): @@ -66,30 +61,15 @@ class RunSQL(Operation): for state_operation in self.state_operations: state_operation.state_forwards(app_label, state) - def _split_sql(self, sql): - regex = r"(?mx) ([^';]* (?:'[^']*'[^';]*)*)" - comment_regex = r"(?mx) (?:^\s*$)|(?:--.*$)" - # First, strip comments - sql = "\n".join([x.strip().replace("%", "%%") for x in re.split(comment_regex, sql) if x.strip()]) - # Now get each statement - for st in re.split(regex, sql)[1:][::2]: - yield st - def database_forwards(self, app_label, schema_editor, from_state, to_state): - if self.multiple: - statements = self._split_sql(self.sql) - else: - statements = [self.sql] + statements = schema_editor.connection.ops.prepare_sql_script(self.sql) for statement in statements: schema_editor.execute(statement) def database_backwards(self, app_label, schema_editor, from_state, to_state): if self.reverse_sql is None: raise NotImplementedError("You cannot reverse this operation") - if self.multiple: - statements = self._split_sql(self.reverse_sql) - else: - statements = [self.reverse_sql] + statements = schema_editor.connection.ops.prepare_sql_script(self.reverse_sql) for statement in statements: schema_editor.execute(statement) -- cgit v1.3