Edit File: reflection.py
try: from collections import OrderedDict except ImportError: OrderedDict = dict from collections import namedtuple from inspect import isclass import re import warnings from peewee import * from peewee import _StringField from peewee import _query_val_transform from peewee import CommaNodeList from peewee import SCOPE_VALUES from peewee import make_snake_case from peewee import text_type try: from pymysql.constants import FIELD_TYPE except ImportError: try: from MySQLdb.constants import FIELD_TYPE except ImportError: FIELD_TYPE = None try: from playhouse import postgres_ext except ImportError: postgres_ext = None try: from playhouse.cockroachdb import CockroachDatabase except ImportError: CockroachDatabase = None RESERVED_WORDS = set([ 'and', 'as', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'exec', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'not', 'or', 'pass', 'print', 'raise', 'return', 'try', 'while', 'with', 'yield', ]) class UnknownField(object): pass class Column(object): """ Store metadata about a database column. """ primary_key_types = (IntegerField, AutoField) def __init__(self, name, field_class, raw_column_type, nullable, primary_key=False, column_name=None, index=False, unique=False, default=None, extra_parameters=None): self.name = name self.field_class = field_class self.raw_column_type = raw_column_type self.nullable = nullable self.primary_key = primary_key self.column_name = column_name self.index = index self.unique = unique self.default = default self.extra_parameters = extra_parameters # Foreign key metadata. self.rel_model = None self.related_name = None self.to_field = None def __repr__(self): attrs = [ 'field_class', 'raw_column_type', 'nullable', 'primary_key', 'column_name'] keyword_args = ', '.join( '%s=%s' % (attr, getattr(self, attr)) for attr in attrs) return 'Column(%s, %s)' % (self.name, keyword_args) def get_field_parameters(self): params = {} if self.extra_parameters is not None: params.update(self.extra_parameters) # Set up default attributes. if self.nullable: params['null'] = True if self.field_class is ForeignKeyField or self.name != self.column_name: params['column_name'] = "'%s'" % self.column_name if self.primary_key and not issubclass(self.field_class, AutoField): params['primary_key'] = True if self.default is not None: params['constraints'] = '[SQL("DEFAULT %s")]' % \ self.default.replace('"', '\\"') # Handle ForeignKeyField-specific attributes. if self.is_foreign_key(): params['model'] = self.rel_model if self.to_field: params['field'] = "'%s'" % self.to_field if self.related_name: params['backref'] = "'%s'" % self.related_name # Handle indexes on column. if not self.is_primary_key(): if self.unique: params['unique'] = 'True' elif self.index and not self.is_foreign_key(): params['index'] = 'True' return params def is_primary_key(self): return self.field_class is AutoField or self.primary_key def is_foreign_key(self): return self.field_class is ForeignKeyField def is_self_referential_fk(self): return (self.field_class is ForeignKeyField and self.rel_model == "'self'") def set_foreign_key(self, foreign_key, model_names, dest=None, related_name=None): self.foreign_key = foreign_key self.field_class = ForeignKeyField if foreign_key.dest_table == foreign_key.table: self.rel_model = "'self'" else: self.rel_model = model_names[foreign_key.dest_table] self.to_field = dest and dest.name or None self.related_name = related_name or None def get_field(self): # Generate the field definition for this column. field_params = {} for key, value in self.get_field_parameters().items(): if isclass(value) and issubclass(value, Field): value = value.__name__ field_params[key] = value param_str = ', '.join('%s=%s' % (k, v) for k, v in sorted(field_params.items())) field = '%s = %s(%s)' % ( self.name, self.field_class.__name__, param_str) if self.field_class is UnknownField: field = '%s # %s' % (field, self.raw_column_type) return field class Metadata(object): column_map = {} extension_import = '' def __init__(self, database): self.database = database self.requires_extension = False def execute(self, sql, *params): return self.database.execute_sql(sql, params) def get_columns(self, table, schema=None): metadata = OrderedDict( (metadata.name, metadata) for metadata in self.database.get_columns(table, schema)) # Look up the actual column type for each column. column_types, extra_params = self.get_column_types(table, schema) # Look up the primary keys. pk_names = self.get_primary_keys(table, schema) if len(pk_names) == 1: pk = pk_names[0] if column_types[pk] is IntegerField: column_types[pk] = AutoField elif column_types[pk] is BigIntegerField: column_types[pk] = BigAutoField columns = OrderedDict() for name, column_data in metadata.items(): field_class = column_types[name] default = self._clean_default(field_class, column_data.default) columns[name] = Column( name, field_class=field_class, raw_column_type=column_data.data_type, nullable=column_data.null, primary_key=column_data.primary_key, column_name=name, default=default, extra_parameters=extra_params.get(name)) return columns def get_column_types(self, table, schema=None): raise NotImplementedError def _clean_default(self, field_class, default): if default is None or field_class in (AutoField, BigAutoField) or \ default.lower() == 'null': return if issubclass(field_class, _StringField) and \ isinstance(default, text_type) and not default.startswith("'"): default = "'%s'" % default return default or "''" def get_foreign_keys(self, table, schema=None): return self.database.get_foreign_keys(table, schema) def get_primary_keys(self, table, schema=None): return self.database.get_primary_keys(table, schema) def get_indexes(self, table, schema=None): return self.database.get_indexes(table, schema) class PostgresqlMetadata(Metadata): column_map = { 16: BooleanField, 17: BlobField, 20: BigIntegerField, 21: SmallIntegerField, 23: IntegerField, 25: TextField, 700: FloatField, 701: DoubleField, 1042: CharField, # blank-padded CHAR 1043: CharField, 1082: DateField, 1114: DateTimeField, 1184: DateTimeField, 1083: TimeField, 1266: TimeField, 1700: DecimalField, 2950: UUIDField, # UUID } array_types = { 1000: BooleanField, 1001: BlobField, 1005: SmallIntegerField, 1007: IntegerField, 1009: TextField, 1014: CharField, 1015: CharField, 1016: BigIntegerField, 1115: DateTimeField, 1182: DateField, 1183: TimeField, 2951: UUIDField, } extension_import = 'from playhouse.postgres_ext import *' def __init__(self, database): super(PostgresqlMetadata, self).__init__(database) if postgres_ext is not None: # Attempt to add types like HStore and JSON. cursor = self.execute('select oid, typname, format_type(oid, NULL)' ' from pg_type;') results = cursor.fetchall() for oid, typname, formatted_type in results: if typname == 'json': self.column_map[oid] = postgres_ext.JSONField elif typname == 'jsonb': self.column_map[oid] = postgres_ext.BinaryJSONField elif typname == 'hstore': self.column_map[oid] = postgres_ext.HStoreField elif typname == 'tsvector': self.column_map[oid] = postgres_ext.TSVectorField for oid in self.array_types: self.column_map[oid] = postgres_ext.ArrayField def get_column_types(self, table, schema): column_types = {} extra_params = {} extension_types = set(( postgres_ext.ArrayField, postgres_ext.BinaryJSONField, postgres_ext.JSONField, postgres_ext.TSVectorField, postgres_ext.HStoreField)) if postgres_ext is not None else set() # Look up the actual column type for each column. identifier = '%s."%s"' % (schema, table) cursor = self.execute( 'SELECT attname, atttypid FROM pg_catalog.pg_attribute ' 'WHERE attrelid = %s::regclass AND attnum > %s', identifier, 0) # Store column metadata in dictionary keyed by column name. for name, oid in cursor.fetchall(): column_types[name] = self.column_map.get(oid, UnknownField) if column_types[name] in extension_types: self.requires_extension = True if oid in self.array_types: extra_params[name] = {'field_class': self.array_types[oid]} return column_types, extra_params def get_columns(self, table, schema=None): schema = schema or 'public' return super(PostgresqlMetadata, self).get_columns(table, schema) def get_foreign_keys(self, table, schema=None): schema = schema or 'public' return super(PostgresqlMetadata, self).get_foreign_keys(table, schema) def get_primary_keys(self, table, schema=None): schema = schema or 'public' return super(PostgresqlMetadata, self).get_primary_keys(table, schema) def get_indexes(self, table, schema=None): schema = schema or 'public' return super(PostgresqlMetadata, self).get_indexes(table, schema) class CockroachDBMetadata(PostgresqlMetadata): # CRDB treats INT the same as BIGINT, so we just map bigint type OIDs to # regular IntegerField. column_map = PostgresqlMetadata.column_map.copy() column_map[20] = IntegerField array_types = PostgresqlMetadata.array_types.copy() array_types[1016] = IntegerField extension_import = 'from playhouse.cockroachdb import *' def __init__(self, database): Metadata.__init__(self, database) self.requires_extension = True if postgres_ext is not None: # Attempt to add JSON types. cursor = self.execute('select oid, typname, format_type(oid, NULL)' ' from pg_type;') results = cursor.fetchall() for oid, typname, formatted_type in results: if typname == 'jsonb': self.column_map[oid] = postgres_ext.BinaryJSONField for oid in self.array_types: self.column_map[oid] = postgres_ext.ArrayField class MySQLMetadata(Metadata): if FIELD_TYPE is None: column_map = {} else: column_map = { FIELD_TYPE.BLOB: TextField, FIELD_TYPE.CHAR: CharField, FIELD_TYPE.DATE: DateField, FIELD_TYPE.DATETIME: DateTimeField, FIELD_TYPE.DECIMAL: DecimalField, FIELD_TYPE.DOUBLE: FloatField, FIELD_TYPE.FLOAT: FloatField, FIELD_TYPE.INT24: IntegerField, FIELD_TYPE.LONG_BLOB: TextField, FIELD_TYPE.LONG: IntegerField, FIELD_TYPE.LONGLONG: BigIntegerField, FIELD_TYPE.MEDIUM_BLOB: TextField, FIELD_TYPE.NEWDECIMAL: DecimalField, FIELD_TYPE.SHORT: IntegerField, FIELD_TYPE.STRING: CharField, FIELD_TYPE.TIMESTAMP: DateTimeField, FIELD_TYPE.TIME: TimeField, FIELD_TYPE.TINY_BLOB: TextField, FIELD_TYPE.TINY: IntegerField, FIELD_TYPE.VAR_STRING: CharField, } def __init__(self, database, **kwargs): if 'password' in kwargs: kwargs['passwd'] = kwargs.pop('password') super(MySQLMetadata, self).__init__(database, **kwargs) def get_column_types(self, table, schema=None): column_types = {} # Look up the actual column type for each column. cursor = self.execute('SELECT * FROM `%s` LIMIT 1' % table) # Store column metadata in dictionary keyed by column name. for column_description in cursor.description: name, type_code = column_description[:2] column_types[name] = self.column_map.get(type_code, UnknownField) return column_types, {} class SqliteMetadata(Metadata): column_map = { 'bigint': BigIntegerField, 'blob': BlobField, 'bool': BooleanField, 'boolean': BooleanField, 'char': CharField, 'date': DateField, 'datetime': DateTimeField, 'decimal': DecimalField, 'float': FloatField, 'integer': IntegerField, 'integer unsigned': IntegerField, 'int': IntegerField, 'long': BigIntegerField, 'numeric': DecimalField, 'real': FloatField, 'smallinteger': IntegerField, 'smallint': IntegerField, 'smallint unsigned': IntegerField, 'text': TextField, 'time': TimeField, 'varchar': CharField, } begin = r'(?:["\[\(]+)?' end = r'(?:["\]\)]+)?' re_foreign_key = ( r'(?:FOREIGN KEY\s*)?' r'{begin}(.+?){end}\s+(?:.+\s+)?' r'references\s+{begin}(.+?){end}' r'\s*\(["|\[]?(.+?)["|\]]?\)').format(begin=begin, end=end) re_varchar = r'^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$' def _map_col(self, column_type): raw_column_type = column_type.lower() if raw_column_type in self.column_map: field_class = self.column_map[raw_column_type] elif re.search(self.re_varchar, raw_column_type): field_class = CharField else: column_type = re.sub(r'\(.+\)', '', raw_column_type) if column_type == '': field_class = BareField else: field_class = self.column_map.get(column_type, UnknownField) return field_class def get_column_types(self, table, schema=None): column_types = {} columns = self.database.get_columns(table) for column in columns: column_types[column.name] = self._map_col(column.data_type) return column_types, {} _DatabaseMetadata = namedtuple('_DatabaseMetadata', ( 'columns', 'primary_keys', 'foreign_keys', 'model_names', 'indexes')) class DatabaseMetadata(_DatabaseMetadata): def multi_column_indexes(self, table): accum = [] for index in self.indexes[table]: if len(index.columns) > 1: field_names = [self.columns[table][column].name for column in index.columns if column in self.columns[table]] accum.append((field_names, index.unique)) return accum def column_indexes(self, table): accum = {} for index in self.indexes[table]: if len(index.columns) == 1: accum[index.columns[0]] = index.unique return accum class Introspector(object): pk_classes = [AutoField, IntegerField] def __init__(self, metadata, schema=None): self.metadata = metadata self.schema = schema def __repr__(self): return '<Introspector: %s>' % self.metadata.database @classmethod def from_database(cls, database, schema=None): if isinstance(database, Proxy): if database.obj is None: raise ValueError('Cannot introspect an uninitialized Proxy.') database = database.obj # Reference the proxied db obj. if CockroachDatabase and isinstance(database, CockroachDatabase): metadata = CockroachDBMetadata(database) elif isinstance(database, PostgresqlDatabase): metadata = PostgresqlMetadata(database) elif isinstance(database, MySQLDatabase): metadata = MySQLMetadata(database) elif isinstance(database, SqliteDatabase): metadata = SqliteMetadata(database) else: raise ValueError('Introspection not supported for %r' % database) return cls(metadata, schema=schema) def get_database_class(self): return type(self.metadata.database) def get_database_name(self): return self.metadata.database.database def get_database_kwargs(self): return self.metadata.database.connect_params def get_additional_imports(self): if self.metadata.requires_extension: return '\n' + self.metadata.extension_import return '' def make_model_name(self, table, snake_case=True): if snake_case: table = make_snake_case(table) model = re.sub(r'[^\w]+', '', table) model_name = ''.join(sub.title() for sub in model.split('_')) if not model_name[0].isalpha(): model_name = 'T' + model_name return model_name def make_column_name(self, column, is_foreign_key=False, snake_case=True): column = column.strip() if snake_case: column = make_snake_case(column) column = column.lower() if is_foreign_key: # Strip "_id" from foreign keys, unless the foreign-key happens to # be named "_id", in which case the name is retained. column = re.sub('_id$', '', column) or column # Remove characters that are invalid for Python identifiers. column = re.sub(r'[^\w]+', '_', column) if column in RESERVED_WORDS: column += '_' if len(column) and column[0].isdigit(): column = '_' + column return column def introspect(self, table_names=None, literal_column_names=False, include_views=False, snake_case=True): # Retrieve all the tables in the database. tables = self.metadata.database.get_tables(schema=self.schema) if include_views: views = self.metadata.database.get_views(schema=self.schema) tables.extend([view.name for view in views]) if table_names is not None: tables = [table for table in tables if table in table_names] table_set = set(tables) # Store a mapping of table name -> dictionary of columns. columns = {} # Store a mapping of table name -> set of primary key columns. primary_keys = {} # Store a mapping of table -> foreign keys. foreign_keys = {} # Store a mapping of table name -> model name. model_names = {} # Store a mapping of table name -> indexes. indexes = {} # Gather the columns for each table. for table in tables: table_indexes = self.metadata.get_indexes(table, self.schema) table_columns = self.metadata.get_columns(table, self.schema) try: foreign_keys[table] = self.metadata.get_foreign_keys( table, self.schema) except ValueError as exc: foreign_keys[table] = [] else: # If there is a possibility we could exclude a dependent table, # ensure that we introspect it so FKs will work. if table_names is not None: for foreign_key in foreign_keys[table]: if foreign_key.dest_table not in table_set: tables.append(foreign_key.dest_table) table_set.add(foreign_key.dest_table) model_names[table] = self.make_model_name(table, snake_case) # Collect sets of all the column names as well as all the # foreign-key column names. lower_col_names = set(column_name.lower() for column_name in table_columns) fks = set(fk_col.column for fk_col in foreign_keys[table]) for col_name, column in table_columns.items(): if literal_column_names: new_name = re.sub(r'[^\w]+', '_', col_name) else: new_name = self.make_column_name(col_name, col_name in fks, snake_case) # If we have two columns, "parent" and "parent_id", ensure # that when we don't introduce naming conflicts. lower_name = col_name.lower() if lower_name.endswith('_id') and new_name in lower_col_names: new_name = col_name.lower() column.name = new_name for index in table_indexes: if len(index.columns) == 1: column = index.columns[0] if column in table_columns: table_columns[column].unique = index.unique table_columns[column].index = True primary_keys[table] = self.metadata.get_primary_keys( table, self.schema) columns[table] = table_columns indexes[table] = table_indexes # Gather all instances where we might have a `related_name` conflict, # either due to multiple FKs on a table pointing to the same table, # or a related_name that would conflict with an existing field. related_names = {} sort_fn = lambda foreign_key: foreign_key.column for table in tables: models_referenced = set() for foreign_key in sorted(foreign_keys[table], key=sort_fn): try: column = columns[table][foreign_key.column] except KeyError: continue dest_table = foreign_key.dest_table if dest_table in models_referenced: related_names[column] = '%s_%s_set' % ( dest_table, column.name) else: models_referenced.add(dest_table) # On the second pass convert all foreign keys. for table in tables: for foreign_key in foreign_keys[table]: src = columns[foreign_key.table][foreign_key.column] try: dest = columns[foreign_key.dest_table][ foreign_key.dest_column] except KeyError: dest = None src.set_foreign_key( foreign_key=foreign_key, model_names=model_names, dest=dest, related_name=related_names.get(src)) return DatabaseMetadata( columns, primary_keys, foreign_keys, model_names, indexes) def generate_models(self, skip_invalid=False, table_names=None, literal_column_names=False, bare_fields=False, include_views=False): database = self.introspect(table_names, literal_column_names, include_views) models = {} class BaseModel(Model): class Meta: database = self.metadata.database schema = self.schema pending = set() def _create_model(table, models): pending.add(table) for foreign_key in database.foreign_keys[table]: dest = foreign_key.dest_table if dest not in models and dest != table: if dest in pending: warnings.warn('Possible reference cycle found between ' '%s and %s' % (table, dest)) else: _create_model(dest, models) primary_keys = [] columns = database.columns[table] for column_name, column in columns.items(): if column.primary_key: primary_keys.append(column.name) multi_column_indexes = database.multi_column_indexes(table) column_indexes = database.column_indexes(table) class Meta: indexes = multi_column_indexes table_name = table # Fix models with multi-column primary keys. composite_key = False if len(primary_keys) == 0: if 'id' not in columns: Meta.primary_key = False else: primary_keys = columns.keys() if len(primary_keys) > 1: Meta.primary_key = CompositeKey(*[ field.name for col, field in columns.items() if col in primary_keys]) composite_key = True attrs = {'Meta': Meta} for column_name, column in columns.items(): FieldClass = column.field_class if FieldClass is not ForeignKeyField and bare_fields: FieldClass = BareField elif FieldClass is UnknownField: FieldClass = BareField params = { 'column_name': column_name, 'null': column.nullable} if column.primary_key and composite_key: if FieldClass is AutoField: FieldClass = IntegerField params['primary_key'] = False elif column.primary_key and FieldClass is not AutoField: params['primary_key'] = True if column.is_foreign_key(): if column.is_self_referential_fk(): params['model'] = 'self' else: dest_table = column.foreign_key.dest_table if dest_table in models: params['model'] = models[dest_table] else: FieldClass = DeferredForeignKey params['rel_model_name'] = dest_table if column.to_field: params['field'] = column.to_field # Generate a unique related name. params['backref'] = '%s_%s_rel' % (table, column_name) if column.default is not None: constraint = SQL('DEFAULT %s' % column.default) params['constraints'] = [constraint] if not column.is_primary_key(): if column_name in column_indexes: if column_indexes[column_name]: params['unique'] = True elif not column.is_foreign_key(): params['index'] = True else: params['index'] = False attrs[column.name] = FieldClass(**params) try: models[table] = type(str(table), (BaseModel,), attrs) except ValueError: if not skip_invalid: raise finally: if table in pending: pending.remove(table) # Actually generate Model classes. for table, model in sorted(database.model_names.items()): if table not in models: _create_model(table, models) return models def introspect(database, schema=None): introspector = Introspector.from_database(database, schema=schema) return introspector.introspect() def generate_models(database, schema=None, **options): introspector = Introspector.from_database(database, schema=schema) return introspector.generate_models(**options) def print_model(model, indexes=True, inline_indexes=False): print(model._meta.name) for field in model._meta.sorted_fields: parts = [' %s %s' % (field.name, field.field_type)] if field.primary_key: parts.append(' PK') elif inline_indexes: if field.unique: parts.append(' UNIQUE') elif field.index: parts.append(' INDEX') if isinstance(field, ForeignKeyField): parts.append(' FK: %s.%s' % (field.rel_model.__name__, field.rel_field.name)) print(''.join(parts)) if indexes: index_list = model._meta.fields_to_index() if not index_list: return print('\nindex(es)') for index in index_list: parts = [' '] ctx = model._meta.database.get_sql_context() with ctx.scope_values(param='%s', quote='""'): ctx.sql(CommaNodeList(index._expressions)) if index._where: ctx.literal(' WHERE ') ctx.sql(index._where) sql, params = ctx.query() clean = sql % tuple(map(_query_val_transform, params)) parts.append(clean.replace('"', '')) if index._unique: parts.append(' UNIQUE') print(''.join(parts)) def get_table_sql(model): sql, params = model._schema._create_table().query() if model._meta.database.param != '%s': sql = sql.replace(model._meta.database.param, '%s') # Format and indent the table declaration, simplest possible approach. match_obj = re.match(r'^(.+?\()(.+)(\).*)', sql) create, columns, extra = match_obj.groups() indented = ',\n'.join(' %s' % column for column in columns.split(', ')) clean = '\n'.join((create, indented, extra)).strip() return clean % tuple(map(_query_val_transform, params)) def print_table_sql(model): print(get_table_sql(model))
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