mirror of
https://github.com/django/django.git
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Fixed #22603 -- Reorganized classes in django.db.backends.
This commit is contained in:
Tim Graham
parent
737d24923a
commit
28308078f3
69 changed files with 3098 additions and 2990 deletions
542
django/db/backends/base/creation.py
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542
django/db/backends/base/creation.py
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@ -0,0 +1,542 @@
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import hashlib
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import sys
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import time
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import warnings
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from django.apps import apps
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from django.conf import settings
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from django.core import serializers
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from django.db import router
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from django.db.backends.utils import truncate_name
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from django.utils.deprecation import RemovedInDjango20Warning
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from django.utils.encoding import force_bytes
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from django.utils.six import StringIO
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from django.utils.six.moves import input
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# The prefix to put on the default database name when creating
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# the test database.
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TEST_DATABASE_PREFIX = 'test_'
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class BaseDatabaseCreation(object):
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"""
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This class encapsulates all backend-specific differences that pertain to
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database *creation*, such as the column types to use for particular Django
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Fields, the SQL used to create and destroy tables, and the creation and
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destruction of test databases.
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"""
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def __init__(self, connection):
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self.connection = connection
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@property
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def _nodb_connection(self):
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"""
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Used to be defined here, now moved to DatabaseWrapper.
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"""
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return self.connection._nodb_connection
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@classmethod
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def _digest(cls, *args):
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"""
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Generates a 32-bit digest of a set of arguments that can be used to
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shorten identifying names.
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"""
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h = hashlib.md5()
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for arg in args:
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h.update(force_bytes(arg))
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return h.hexdigest()[:8]
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def sql_create_model(self, model, style, known_models=set()):
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"""
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Returns the SQL required to create a single model, as a tuple of:
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(list_of_sql, pending_references_dict)
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"""
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opts = model._meta
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if not opts.managed or opts.proxy or opts.swapped:
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return [], {}
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final_output = []
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table_output = []
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pending_references = {}
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qn = self.connection.ops.quote_name
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for f in opts.local_fields:
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db_params = f.db_parameters(connection=self.connection)
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col_type = db_params['type']
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if db_params['check']:
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col_type = '%s CHECK (%s)' % (col_type, db_params['check'])
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col_type_suffix = f.db_type_suffix(connection=self.connection)
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tablespace = f.db_tablespace or opts.db_tablespace
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if col_type is None:
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# Skip ManyToManyFields, because they're not represented as
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# database columns in this table.
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continue
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# Make the definition (e.g. 'foo VARCHAR(30)') for this field.
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field_output = [style.SQL_FIELD(qn(f.column)),
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style.SQL_COLTYPE(col_type)]
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# Oracle treats the empty string ('') as null, so coerce the null
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# option whenever '' is a possible value.
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null = f.null
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if (f.empty_strings_allowed and not f.primary_key and
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self.connection.features.interprets_empty_strings_as_nulls):
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null = True
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if not null:
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field_output.append(style.SQL_KEYWORD('NOT NULL'))
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if f.primary_key:
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field_output.append(style.SQL_KEYWORD('PRIMARY KEY'))
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elif f.unique:
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field_output.append(style.SQL_KEYWORD('UNIQUE'))
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if tablespace and f.unique:
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# We must specify the index tablespace inline, because we
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# won't be generating a CREATE INDEX statement for this field.
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tablespace_sql = self.connection.ops.tablespace_sql(
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tablespace, inline=True)
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if tablespace_sql:
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field_output.append(tablespace_sql)
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if f.rel and f.db_constraint:
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ref_output, pending = self.sql_for_inline_foreign_key_references(
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model, f, known_models, style)
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if pending:
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pending_references.setdefault(f.rel.to, []).append(
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(model, f))
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else:
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field_output.extend(ref_output)
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if col_type_suffix:
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field_output.append(style.SQL_KEYWORD(col_type_suffix))
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table_output.append(' '.join(field_output))
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for field_constraints in opts.unique_together:
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table_output.append(style.SQL_KEYWORD('UNIQUE') + ' (%s)' %
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", ".join(
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[style.SQL_FIELD(qn(opts.get_field(f).column))
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for f in field_constraints]))
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full_statement = [style.SQL_KEYWORD('CREATE TABLE') + ' ' +
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style.SQL_TABLE(qn(opts.db_table)) + ' (']
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for i, line in enumerate(table_output): # Combine and add commas.
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full_statement.append(
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' %s%s' % (line, ',' if i < len(table_output) - 1 else ''))
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full_statement.append(')')
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if opts.db_tablespace:
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tablespace_sql = self.connection.ops.tablespace_sql(
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opts.db_tablespace)
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if tablespace_sql:
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full_statement.append(tablespace_sql)
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full_statement.append(';')
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final_output.append('\n'.join(full_statement))
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if opts.has_auto_field:
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# Add any extra SQL needed to support auto-incrementing primary
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# keys.
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auto_column = opts.auto_field.db_column or opts.auto_field.name
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autoinc_sql = self.connection.ops.autoinc_sql(opts.db_table,
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auto_column)
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if autoinc_sql:
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for stmt in autoinc_sql:
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final_output.append(stmt)
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return final_output, pending_references
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def sql_for_inline_foreign_key_references(self, model, field, known_models, style):
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"""
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Return the SQL snippet defining the foreign key reference for a field.
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"""
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qn = self.connection.ops.quote_name
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rel_to = field.rel.to
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if rel_to in known_models or rel_to == model:
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output = [style.SQL_KEYWORD('REFERENCES') + ' ' +
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style.SQL_TABLE(qn(rel_to._meta.db_table)) + ' (' +
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style.SQL_FIELD(qn(rel_to._meta.get_field(
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field.rel.field_name).column)) + ')' +
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self.connection.ops.deferrable_sql()
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]
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pending = False
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else:
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# We haven't yet created the table to which this field
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# is related, so save it for later.
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output = []
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pending = True
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return output, pending
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def sql_for_pending_references(self, model, style, pending_references):
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"""
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Returns any ALTER TABLE statements to add constraints after the fact.
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"""
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opts = model._meta
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if not opts.managed or opts.swapped:
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return []
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qn = self.connection.ops.quote_name
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final_output = []
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if model in pending_references:
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for rel_class, f in pending_references[model]:
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rel_opts = rel_class._meta
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r_table = rel_opts.db_table
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r_col = f.column
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table = opts.db_table
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col = opts.get_field(f.rel.field_name).column
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# For MySQL, r_name must be unique in the first 64 characters.
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# So we are careful with character usage here.
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r_name = '%s_refs_%s_%s' % (
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r_col, col, self._digest(r_table, table))
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final_output.append(style.SQL_KEYWORD('ALTER TABLE') +
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' %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' %
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(qn(r_table), qn(truncate_name(
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r_name, self.connection.ops.max_name_length())),
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qn(r_col), qn(table), qn(col),
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self.connection.ops.deferrable_sql()))
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del pending_references[model]
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return final_output
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def sql_indexes_for_model(self, model, style):
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"""
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Returns the CREATE INDEX SQL statements for a single model.
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"""
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warnings.warn("DatabaseCreation.sql_indexes_for_model is deprecated, "
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"use the equivalent method of the schema editor instead.",
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RemovedInDjango20Warning)
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if not model._meta.managed or model._meta.proxy or model._meta.swapped:
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return []
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output = []
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for f in model._meta.local_fields:
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output.extend(self.sql_indexes_for_field(model, f, style))
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for fs in model._meta.index_together:
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fields = [model._meta.get_field(f) for f in fs]
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output.extend(self.sql_indexes_for_fields(model, fields, style))
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return output
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def sql_indexes_for_field(self, model, f, style):
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"""
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Return the CREATE INDEX SQL statements for a single model field.
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"""
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if f.db_index and not f.unique:
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return self.sql_indexes_for_fields(model, [f], style)
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else:
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return []
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def sql_indexes_for_fields(self, model, fields, style):
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if len(fields) == 1 and fields[0].db_tablespace:
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tablespace_sql = self.connection.ops.tablespace_sql(fields[0].db_tablespace)
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elif model._meta.db_tablespace:
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tablespace_sql = self.connection.ops.tablespace_sql(model._meta.db_tablespace)
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else:
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tablespace_sql = ""
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if tablespace_sql:
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tablespace_sql = " " + tablespace_sql
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field_names = []
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qn = self.connection.ops.quote_name
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for f in fields:
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field_names.append(style.SQL_FIELD(qn(f.column)))
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index_name = "%s_%s" % (model._meta.db_table, self._digest([f.name for f in fields]))
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return [
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style.SQL_KEYWORD("CREATE INDEX") + " " +
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style.SQL_TABLE(qn(truncate_name(index_name, self.connection.ops.max_name_length()))) + " " +
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style.SQL_KEYWORD("ON") + " " +
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style.SQL_TABLE(qn(model._meta.db_table)) + " " +
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"(%s)" % style.SQL_FIELD(", ".join(field_names)) +
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"%s;" % tablespace_sql,
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]
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def sql_destroy_model(self, model, references_to_delete, style):
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"""
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Return the DROP TABLE and restraint dropping statements for a single
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model.
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"""
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if not model._meta.managed or model._meta.proxy or model._meta.swapped:
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return []
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# Drop the table now
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qn = self.connection.ops.quote_name
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output = ['%s %s;' % (style.SQL_KEYWORD('DROP TABLE'),
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style.SQL_TABLE(qn(model._meta.db_table)))]
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if model in references_to_delete:
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output.extend(self.sql_remove_table_constraints(
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model, references_to_delete, style))
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if model._meta.has_auto_field:
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ds = self.connection.ops.drop_sequence_sql(model._meta.db_table)
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if ds:
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output.append(ds)
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return output
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def sql_remove_table_constraints(self, model, references_to_delete, style):
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if not model._meta.managed or model._meta.proxy or model._meta.swapped:
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return []
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output = []
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qn = self.connection.ops.quote_name
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for rel_class, f in references_to_delete[model]:
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table = rel_class._meta.db_table
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col = f.column
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r_table = model._meta.db_table
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r_col = model._meta.get_field(f.rel.field_name).column
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r_name = '%s_refs_%s_%s' % (
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col, r_col, self._digest(table, r_table))
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output.append('%s %s %s %s;' % (
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style.SQL_KEYWORD('ALTER TABLE'),
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style.SQL_TABLE(qn(table)),
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style.SQL_KEYWORD(self.connection.ops.drop_foreignkey_sql()),
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style.SQL_FIELD(qn(truncate_name(
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r_name, self.connection.ops.max_name_length())))
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))
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del references_to_delete[model]
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return output
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def sql_destroy_indexes_for_model(self, model, style):
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"""
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Returns the DROP INDEX SQL statements for a single model.
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"""
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if not model._meta.managed or model._meta.proxy or model._meta.swapped:
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return []
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output = []
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for f in model._meta.local_fields:
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output.extend(self.sql_destroy_indexes_for_field(model, f, style))
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for fs in model._meta.index_together:
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fields = [model._meta.get_field(f) for f in fs]
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output.extend(self.sql_destroy_indexes_for_fields(model, fields, style))
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return output
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def sql_destroy_indexes_for_field(self, model, f, style):
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"""
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Return the DROP INDEX SQL statements for a single model field.
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"""
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if f.db_index and not f.unique:
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return self.sql_destroy_indexes_for_fields(model, [f], style)
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else:
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return []
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def sql_destroy_indexes_for_fields(self, model, fields, style):
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if len(fields) == 1 and fields[0].db_tablespace:
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tablespace_sql = self.connection.ops.tablespace_sql(fields[0].db_tablespace)
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elif model._meta.db_tablespace:
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tablespace_sql = self.connection.ops.tablespace_sql(model._meta.db_tablespace)
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else:
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tablespace_sql = ""
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if tablespace_sql:
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tablespace_sql = " " + tablespace_sql
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field_names = []
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qn = self.connection.ops.quote_name
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for f in fields:
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field_names.append(style.SQL_FIELD(qn(f.column)))
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index_name = "%s_%s" % (model._meta.db_table, self._digest([f.name for f in fields]))
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return [
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style.SQL_KEYWORD("DROP INDEX") + " " +
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style.SQL_TABLE(qn(truncate_name(index_name, self.connection.ops.max_name_length()))) + " " +
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";",
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]
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def create_test_db(self, verbosity=1, autoclobber=False, serialize=True, keepdb=False):
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"""
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Creates a test database, prompting the user for confirmation if the
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database already exists. Returns the name of the test database created.
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"""
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# Don't import django.core.management if it isn't needed.
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from django.core.management import call_command
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test_database_name = self._get_test_db_name()
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if verbosity >= 1:
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test_db_repr = ''
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action = 'Creating'
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if verbosity >= 2:
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test_db_repr = " ('%s')" % test_database_name
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if keepdb:
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action = "Using existing"
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print("%s test database for alias '%s'%s..." % (
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action, self.connection.alias, test_db_repr))
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# We could skip this call if keepdb is True, but we instead
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# give it the keepdb param. This is to handle the case
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# where the test DB doesn't exist, in which case we need to
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# create it, then just not destroy it. If we instead skip
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# this, we will get an exception.
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self._create_test_db(verbosity, autoclobber, keepdb)
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self.connection.close()
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settings.DATABASES[self.connection.alias]["NAME"] = test_database_name
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self.connection.settings_dict["NAME"] = test_database_name
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# We report migrate messages at one level lower than that requested.
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# This ensures we don't get flooded with messages during testing
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# (unless you really ask to be flooded).
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call_command(
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'migrate',
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verbosity=max(verbosity - 1, 0),
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interactive=False,
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database=self.connection.alias,
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test_flush=True,
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)
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# We then serialize the current state of the database into a string
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# and store it on the connection. This slightly horrific process is so people
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# who are testing on databases without transactions or who are using
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# a TransactionTestCase still get a clean database on every test run.
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if serialize:
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self.connection._test_serialized_contents = self.serialize_db_to_string()
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call_command('createcachetable', database=self.connection.alias)
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# Ensure a connection for the side effect of initializing the test database.
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self.connection.ensure_connection()
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return test_database_name
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def serialize_db_to_string(self):
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"""
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Serializes all data in the database into a JSON string.
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Designed only for test runner usage; will not handle large
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amounts of data.
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"""
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# Build list of all apps to serialize
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from django.db.migrations.loader import MigrationLoader
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loader = MigrationLoader(self.connection)
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app_list = []
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for app_config in apps.get_app_configs():
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if (
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app_config.models_module is not None and
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app_config.label in loader.migrated_apps and
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app_config.name not in settings.TEST_NON_SERIALIZED_APPS
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):
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app_list.append((app_config, None))
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# Make a function to iteratively return every object
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def get_objects():
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for model in serializers.sort_dependencies(app_list):
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if (not model._meta.proxy and model._meta.managed and
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router.allow_migrate(self.connection.alias, model)):
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queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)
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for obj in queryset.iterator():
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yield obj
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# Serialise to a string
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out = StringIO()
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serializers.serialize("json", get_objects(), indent=None, stream=out)
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return out.getvalue()
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def deserialize_db_from_string(self, data):
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"""
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Reloads the database with data from a string generated by
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the serialize_db_to_string method.
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"""
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data = StringIO(data)
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for obj in serializers.deserialize("json", data, using=self.connection.alias):
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obj.save()
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def _get_test_db_name(self):
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"""
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Internal implementation - returns the name of the test DB that will be
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created. Only useful when called from create_test_db() and
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_create_test_db() and when no external munging is done with the 'NAME'
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or 'TEST_NAME' settings.
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"""
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if self.connection.settings_dict['TEST']['NAME']:
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return self.connection.settings_dict['TEST']['NAME']
|
||||
return TEST_DATABASE_PREFIX + self.connection.settings_dict['NAME']
|
||||
|
||||
def _create_test_db(self, verbosity, autoclobber, keepdb=False):
|
||||
"""
|
||||
Internal implementation - creates the test db tables.
|
||||
"""
|
||||
suffix = self.sql_table_creation_suffix()
|
||||
|
||||
test_database_name = self._get_test_db_name()
|
||||
|
||||
qn = self.connection.ops.quote_name
|
||||
|
||||
# Create the test database and connect to it.
|
||||
with self._nodb_connection.cursor() as cursor:
|
||||
try:
|
||||
cursor.execute(
|
||||
"CREATE DATABASE %s %s" % (qn(test_database_name), suffix))
|
||||
except Exception as e:
|
||||
# if we want to keep the db, then no need to do any of the below,
|
||||
# just return and skip it all.
|
||||
if keepdb:
|
||||
return test_database_name
|
||||
|
||||
sys.stderr.write(
|
||||
"Got an error creating the test database: %s\n" % e)
|
||||
if not autoclobber:
|
||||
confirm = input(
|
||||
"Type 'yes' if you would like to try deleting the test "
|
||||
"database '%s', or 'no' to cancel: " % test_database_name)
|
||||
if autoclobber or confirm == 'yes':
|
||||
try:
|
||||
if verbosity >= 1:
|
||||
print("Destroying old test database '%s'..."
|
||||
% self.connection.alias)
|
||||
cursor.execute(
|
||||
"DROP DATABASE %s" % qn(test_database_name))
|
||||
cursor.execute(
|
||||
"CREATE DATABASE %s %s" % (qn(test_database_name),
|
||||
suffix))
|
||||
except Exception as e:
|
||||
sys.stderr.write(
|
||||
"Got an error recreating the test database: %s\n" % e)
|
||||
sys.exit(2)
|
||||
else:
|
||||
print("Tests cancelled.")
|
||||
sys.exit(1)
|
||||
|
||||
return test_database_name
|
||||
|
||||
def destroy_test_db(self, old_database_name, verbosity=1, keepdb=False):
|
||||
"""
|
||||
Destroy a test database, prompting the user for confirmation if the
|
||||
database already exists.
|
||||
"""
|
||||
self.connection.close()
|
||||
test_database_name = self.connection.settings_dict['NAME']
|
||||
if verbosity >= 1:
|
||||
test_db_repr = ''
|
||||
action = 'Destroying'
|
||||
if verbosity >= 2:
|
||||
test_db_repr = " ('%s')" % test_database_name
|
||||
if keepdb:
|
||||
action = 'Preserving'
|
||||
print("%s test database for alias '%s'%s..." % (
|
||||
action, self.connection.alias, test_db_repr))
|
||||
|
||||
# if we want to preserve the database
|
||||
# skip the actual destroying piece.
|
||||
if not keepdb:
|
||||
self._destroy_test_db(test_database_name, verbosity)
|
||||
|
||||
# Restore the original database name
|
||||
settings.DATABASES[self.connection.alias]["NAME"] = old_database_name
|
||||
self.connection.settings_dict["NAME"] = old_database_name
|
||||
|
||||
def _destroy_test_db(self, test_database_name, verbosity):
|
||||
"""
|
||||
Internal implementation - remove the test db tables.
|
||||
"""
|
||||
# Remove the test database to clean up after
|
||||
# ourselves. Connect to the previous database (not the test database)
|
||||
# to do so, because it's not allowed to delete a database while being
|
||||
# connected to it.
|
||||
with self._nodb_connection.cursor() as cursor:
|
||||
# Wait to avoid "database is being accessed by other users" errors.
|
||||
time.sleep(1)
|
||||
cursor.execute("DROP DATABASE %s"
|
||||
% self.connection.ops.quote_name(test_database_name))
|
||||
|
||||
def sql_table_creation_suffix(self):
|
||||
"""
|
||||
SQL to append to the end of the test table creation statements.
|
||||
"""
|
||||
return ''
|
||||
|
||||
def test_db_signature(self):
|
||||
"""
|
||||
Returns a tuple with elements of self.connection.settings_dict (a
|
||||
DATABASES setting value) that uniquely identify a database
|
||||
accordingly to the RDBMS particularities.
|
||||
"""
|
||||
settings_dict = self.connection.settings_dict
|
||||
return (
|
||||
settings_dict['HOST'],
|
||||
settings_dict['PORT'],
|
||||
settings_dict['ENGINE'],
|
||||
settings_dict['NAME']
|
||||
)
|
||||
Loading…
Add table
Add a link
Reference in a new issue