Commit d61b6224 authored by Loic Bistuer's avatar Loic Bistuer Committed by Tim Graham
Browse files

[1.7.x] Fixed #22424 -- Fixed handling of default values for TextField/BinaryField on MySQL.

Thanks syphar for the review and suggestions.

Backport of 1d3d01b4 from master
parent 1a29675d
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+25 −1
Original line number Diff line number Diff line
from django.db.backends.schema import BaseDatabaseSchemaEditor
from django.db.models import NOT_PROVIDED


class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
@@ -28,4 +29,27 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
    def quote_value(self, value):
        # Inner import to allow module to fail to load gracefully
        import MySQLdb.converters

        if isinstance(value, six.string_types):
            return '"%s"' % six.text_type(value)
        else:
            return MySQLdb.escape(value, MySQLdb.converters.conversions)

    def skip_default(self, field):
        """
        MySQL doesn't accept default values for longtext and longblob
        and implicitly treats these columns as nullable.
        """
        return field.db_type(self.connection) in {'longtext', 'longblob'}

    def add_field(self, model, field):
        super(DatabaseSchemaEditor, self).add_field(model, field)

        # Simulate the effect of a one-off default.
        if self.skip_default(field) and field.default not in {None, NOT_PROVIDED}:
            effective_default = self.effective_default(field)
            self.execute('UPDATE %(table)s SET %(column)s=%(default)s' % {
                'table': self.quote_name(model._meta.db_table),
                'column': self.quote_name(field.column),
                'default': self.quote_value(effective_default),
            })
+9 −1
Original line number Diff line number Diff line
@@ -118,6 +118,7 @@ class BaseDatabaseSchemaEditor(object):
        null = field.null
        # If we were told to include a default value, do so
        default_value = self.effective_default(field)
        include_default = include_default and not self.skip_default(field)
        if include_default and default_value is not None:
            if self.connection.features.requires_literal_defaults:
                # Some databases can't take defaults as a parameter (oracle)
@@ -148,6 +149,13 @@ class BaseDatabaseSchemaEditor(object):
        # Return the sql
        return sql, params

    def skip_default(self, field):
        """
        Some backends don't accept default values for certain columns types
        (i.e. MySQL longtext and longblob).
        """
        return False

    def prepare_default(self, value):
        """
        Only used for backends which have requires_literal_defaults feature
@@ -398,7 +406,7 @@ class BaseDatabaseSchemaEditor(object):
        self.execute(sql, params)
        # Drop the default if we need to
        # (Django usually does not use in-database defaults)
        if field.default is not None:
        if not self.skip_default(field) and field.default is not None:
            sql = self.sql_alter_column % {
                "table": self.quote_name(model._meta.db_table),
                "changes": self.sql_alter_column_no_default % {
+111 −0
Original line number Diff line number Diff line
from __future__ import unicode_literals

import unittest

try:
@@ -312,6 +314,115 @@ class OperationTests(MigrationTestBase):
            operation.database_backwards("test_adfl", editor, new_state, project_state)
        self.assertColumnNotExists("test_adfl_pony", "height")

    def test_add_charfield(self):
        """
        Tests the AddField operation on TextField.
        """
        project_state = self.set_up_test_model("test_adchfl")

        new_apps = project_state.render()
        Pony = new_apps.get_model("test_adchfl", "Pony")
        pony = Pony.objects.create(weight=42)

        new_state = self.apply_operations("test_adchfl", project_state, [
            migrations.AddField(
                "Pony",
                "text",
                models.CharField(max_length=10, default="some text"),
            ),
            migrations.AddField(
                "Pony",
                "empty",
                models.CharField(max_length=10, default=""),
            ),
            # If not properly quoted digits would be interpreted as an int.
            migrations.AddField(
                "Pony",
                "digits",
                models.CharField(max_length=10, default="42"),
            ),
        ])

        new_apps = new_state.render()
        Pony = new_apps.get_model("test_adchfl", "Pony")
        pony = Pony.objects.get(pk=pony.pk)
        self.assertEqual(pony.text, "some text")
        self.assertEqual(pony.empty, "")
        self.assertEqual(pony.digits, "42")

    def test_add_textfield(self):
        """
        Tests the AddField operation on TextField.
        """
        project_state = self.set_up_test_model("test_adtxtfl")

        new_apps = project_state.render()
        Pony = new_apps.get_model("test_adtxtfl", "Pony")
        pony = Pony.objects.create(weight=42)

        new_state = self.apply_operations("test_adtxtfl", project_state, [
            migrations.AddField(
                "Pony",
                "text",
                models.TextField(default="some text"),
            ),
            migrations.AddField(
                "Pony",
                "empty",
                models.TextField(default=""),
            ),
            # If not properly quoted digits would be interpreted as an int.
            migrations.AddField(
                "Pony",
                "digits",
                models.TextField(default="42"),
            ),
        ])

        new_apps = new_state.render()
        Pony = new_apps.get_model("test_adtxtfl", "Pony")
        pony = Pony.objects.get(pk=pony.pk)
        self.assertEqual(pony.text, "some text")
        self.assertEqual(pony.empty, "")
        self.assertEqual(pony.digits, "42")

    def test_add_binaryfield(self):
        """
        Tests the AddField operation on TextField/BinaryField.
        """
        project_state = self.set_up_test_model("test_adbinfl")

        new_apps = project_state.render()
        Pony = new_apps.get_model("test_adbinfl", "Pony")
        pony = Pony.objects.create(weight=42)

        new_state = self.apply_operations("test_adbinfl", project_state, [
            migrations.AddField(
                "Pony",
                "blob",
                models.BinaryField(default=b"some text"),
            ),
            migrations.AddField(
                "Pony",
                "empty",
                models.BinaryField(default=b""),
            ),
            # If not properly quoted digits would be interpreted as an int.
            migrations.AddField(
                "Pony",
                "digits",
                models.BinaryField(default=b"42"),
            ),
        ])

        new_apps = new_state.render()
        Pony = new_apps.get_model("test_adbinfl", "Pony")
        pony = Pony.objects.get(pk=pony.pk)
        # SQLite returns buffer/memoryview, cast to bytes for checking.
        self.assertEqual(bytes(pony.blob), b"some text")
        self.assertEqual(bytes(pony.empty), b"")
        self.assertEqual(bytes(pony.digits), b"42")

    def test_column_name_quoting(self):
        """
        Column names that are SQL keywords shouldn't cause problems when used