Django项目启动 AttributeError: ‘str‘ object has no attribute ‘decode‘ 问题

2022-07-23 22:33:10 阅读：215 来源： 互联网

标签：py lib Anaconda3 attribute object Django File line packages

Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "D:\Anaconda3\lib\threading.py", line 980, in _bootstrap_inner
    self.run()
  File "D:\Anaconda3\lib\threading.py", line 917, in run
    self._target(*self._args, **self._kwargs)
  File "D:\Anaconda3\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "D:\Anaconda3\lib\site-packages\django\core\management\commands\runserver.py", line 120, in inner_run
    self.check_migrations()
  File "D:\Anaconda3\lib\site-packages\django\core\management\base.py", line 453, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\loader.py", line 49, in __init__
    self.build_graph()
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\loader.py", line 212, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\recorder.py", line 73, in applied_migrations
    if self.has_table():
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\recorder.py", line 56, in has_table
    return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\base.py", line 256, in cursor
    return self._cursor()
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\base.py", line 233, in _cursor
    self.ensure_connection()
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\base.py", line 217, in ensure_connection
    self.connect()
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\base.py", line 197, in connect
    self.init_connection_state()
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\base.py", line 231, in init_connection_state
    if self.features.is_sql_auto_is_null_enabled:
  File "D:\Anaconda3\lib\site-packages\django\utils\functional.py", line 80, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\features.py", line 82, in is_sql_auto_is_null_enabled
    cursor.execute('SELECT @@SQL_AUTO_IS_NULL')
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 103, in execute
    sql = self.db.ops.last_executed_query(self.cursor, sql, params)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\operations.py", line 146, in last_executed_query
    query = query.decode(errors='replace')
AttributeError: 'str' object has no attribute 'decode'
D:\Anaconda3\Lib\site-packages\django\db\backends\mysql\operations.py changed, reloading.
Performing system checks...

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System check identified no issues (0 silenced).
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 82, in _execute
    return self.cursor.execute(sql)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "D:\Anaconda3\lib\site-packages\pymysql\cursors.py", line 148, in execute
    result = self._query(query)
  File "D:\Anaconda3\lib\site-packages\pymysql\cursors.py", line 310, in _query
    conn.query(q)
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 548, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 775, in _read_query_result
    result.read()
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 1156, in read
    first_packet = self.connection._read_packet()
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "D:\Anaconda3\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "D:\Anaconda3\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.OperationalError: (1046, 'No database selected')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "D:\Anaconda3\lib\threading.py", line 980, in _bootstrap_inner
    self.run()
  File "D:\Anaconda3\lib\threading.py", line 917, in run
    self._target(*self._args, **self._kwargs)
  File "D:\Anaconda3\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "D:\Anaconda3\lib\site-packages\django\core\management\commands\runserver.py", line 120, in inner_run
    self.check_migrations()
  File "D:\Anaconda3\lib\site-packages\django\core\management\base.py", line 453, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\loader.py", line 49, in __init__
    self.build_graph()
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\loader.py", line 212, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\recorder.py", line 73, in applied_migrations
    if self.has_table():
  File "D:\Anaconda3\lib\site-packages\django\db\migrations\recorder.py", line 56, in has_table
    return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\introspection.py", line 48, in table_names
    return get_names(cursor)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\base\introspection.py", line 43, in get_names
    return sorted(ti.name for ti in self.get_table_list(cursor)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\introspection.py", line 55, in get_table_list
    cursor.execute("SHOW FULL TABLES")
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 99, in execute
    return super().execute(sql, params)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 67, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "D:\Anaconda3\lib\site-packages\django\db\utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "D:\Anaconda3\lib\site-packages\django\db\backends\utils.py", line 82, in _execute
    return self.cursor.execute(sql)
  File "D:\Anaconda3\lib\site-packages\django\db\backends\mysql\base.py", line 71, in execute
    return self.cursor.execute(query, args)
  File "D:\Anaconda3\lib\site-packages\pymysql\cursors.py", line 148, in execute
    result = self._query(query)
  File "D:\Anaconda3\lib\site-packages\pymysql\cursors.py", line 310, in _query
    conn.query(q)
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 548, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 775, in _read_query_result
    result.read()
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 1156, in read
    first_packet = self.connection._read_packet()
  File "D:\Anaconda3\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "D:\Anaconda3\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "D:\Anaconda3\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
django.db.utils.OperationalError: (1046, 'No database selected')

Django启动时报错

问题原因：

从 Error信息中可以得知，这是 str编码的问题，而且还是和 mysql进行交互之间的编码问题。
python3里面，字符串要先encode手动指定其为某一编码的字节码之后，才能decode解码。

SO:

　　点击最后一条异常信息的地址，将query = query.decode(errors='replace') 修改成 query = query.encode(errors='replace')

标签：py,lib,Anaconda3,attribute,object,Django,File,line,packages
来源： https://www.cnblogs.com/hkwJsxl/p/16513232.html

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Django项目启动 AttributeError: ‘str‘ object has no attribute ‘decode‘ 问题

问题原因：

SO: