Writing to Oracle: TypeError: expecting string or bytes object

Question

我一直为此伤脑筋。我试图将 65000 多行和 51 列推送到 oracle DB，但我最终收到类型错误。有没有办法找出这个错误来自哪一列，以便我进行调试。

另一个问题 - python dataframe 中的数据类型“Object”是否可以读取为 Oracle 中的 'Number' Dtype？

Traceback (most recent call last):

  File "c:\users\so-go- activating strategic people capability - deliverable files\ finance\codes-to_use\s1_3_supply_forecasting_input_revamped.py", line 160, in <module>
    hcar.to_sql('HISTORICAL_HCAR', engine, if_exists='append', index=False,schema='HIM_PA_EXTERN_PROD_FIN',dtype=dtyp)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\pandas\core\generic.py", line 2605, in to_sql
    sql.to_sql(

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\pandas\io\sql.py", line 589, in to_sql
    pandas_sql.to_sql(

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\pandas\io\sql.py", line 1398, in to_sql
    table.insert(chunksize, method=method)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\pandas\io\sql.py", line 830, in insert
    exec_insert(conn, keys, chunk_iter)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\pandas\io\sql.py", line 747, in _execute_insert
    conn.execute(self.table.insert(), data)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\engine\base.py", line 1011, in execute
    return meth(self, multiparams, params)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\sql\elements.py", line 298, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\engine\base.py", line 1124, in _execute_clauseelement
    ret = self._execute_context(

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\engine\base.py", line 1316, in _execute_context
    self._handle_dbapi_exception(

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\engine\base.py", line 1514, in _handle_dbapi_exception
    util.raise_(exc_info[1], with_traceback=exc_info[2])

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\util\compat.py", line 182, in raise_
    raise exception

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\engine\base.py", line 1256, in _execute_context
    self.dialect.do_executemany(

  File "C:\ProgramData\Anaconda3-2020.11\lib\site-packages\sqlalchemy\dialects\oracle\cx_oracle.py", line 1182, in do_executemany
    cursor.executemany(statement, parameters)

TypeError: expecting string or bytes object

Answer 1

遗憾的是，Oracle 不会告诉您是哪一列导致了错误。所以这是一个 Python / cx_Oracle 问题，而不是真正的 Oracle 问题。我假设当你说“dataframe”时，你的意思是 Pandas dataframe，而不是 PySpark/Dask/Veux/etc.

关于 Pandas 个数据帧的错误 similar 。问题通常是 Pandas 数据框列有一个 dtype，但 行不必全部匹配该类型 - object 列将每行允许不同的类型。

# example - an int, a float, and a str in the same column
pd.DataFrame([12, np.NaN, 'hi'], columns=['ABC'])

当您（或 sqlalchemy）使用 executemany() 时，所有行都必须具有相同的匹配列类型集。

You can check the types in a single column 通过使用：

df['ABC'].map(type)

因此，您可以使用类似以下内容一次检查数据框中的所有列：

df.applymap(type).nunique()

显示每列包含的类型数。任何大于 1 的列都可能导致此错误。在发送到 Oracle 之前使用 df['ABC'].astype(str) 或 df['ABC'].fillna('') 修复它。

Writing to Oracle: TypeError: expecting string or bytes object

Writing to Oracle: TypeError: expecting string or bytes object

python

oracle

cx-oracle

sqlalchemy

pandas