MySQLdb：Pandas 数据框到 SQL 数据库错误：字符串格式化期间并非所有参数都转换

Posted 2023-02-24

【中文标题】MySQLdb：Pandas 数据框到 SQL 数据库错误：字符串格式化期间并非所有参数都转换

【英文标题】：MySQLdb: Pandas data-frame to SQL database error: not all arguments converted during string formatting

【发布时间】：2018-11-22 06:02:33

【问题描述】：

所以，我想将数据框移动到数据库中，但我遇到了一些问题。我使用 pandas 库制作了数据框，并希望将数据上传到我的数据库中的表中。

我的代码的相关sn-ps和错误详情如下：

#CONNECTION TO SQL DATABASE
db=sql.connect(host="localhost",user="root",passwd="password",db="database_name")
cur=db.cursor()
#CONVERTING DATAFRAME(df_final) INTO TABLE
df_final.to_sql(con=db, name='finaltable', if_exists='replace', chunksize=5000)

错误详情：

Traceback (most recent call last):
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\M
ySQLdb\cursors.py", line 238, in execute
query = query % args
TypeError: not all arguments converted during string formatting

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 1400, in execute
cur.execute(*args)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\M
ySQLdb\cursors.py", line 240, in execute
self.errorhandler(self, ProgrammingError, str(m))
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\M
ySQLdb\connections.py", line 52, in defaulterrorhandler
raise errorclass(errorvalue)
_mysql_exceptions.ProgrammingError: not all arguments converted during string fo
rmatting

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "pt.py", line 77, in <module>
df_final.to_sql(con=db, name='finaltable', if_exists='replace', chunksize=50
00)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\core\generic.py", line 2127, in to_sql
dtype=dtype)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 450, in to_sql
chunksize=chunksize, dtype=dtype)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 1502, in to_sql
table.create()
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 561, in create
if self.exists():
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 549, in exists
return self.pd_sql.has_table(self.name, self.schema)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 1514, in has_table
return len(self.execute(query, [name, ]).fetchall()) > 0
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 1412, in execute
raise_with_traceback(ex)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\compat\__init__.py", line 403, in raise_with_traceback
raise exc.with_traceback(traceback)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\p
andas\io\sql.py", line 1400, in execute
cur.execute(*args)
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\M
ySQLdb\cursors.py", line 240, in execute
self.errorhandler(self, ProgrammingError, str(m))
File "C:\Users\DELL\AppData\Local\Programs\Python\Python36\lib\site-packages\M
ySQLdb\connections.py", line 52, in defaulterrorhandler
raise errorclass(errorvalue)
pandas.io.sql.DatabaseError: Execution failed on sql 'SELECT name FROM 
sqlite_ma
ster WHERE type='table' AND name=?;': not all arguments converted during string
formatting

【参考方案1】：

显然，由于更新，我的方法已经过时，因此对于连接位，我使用“sqlalchemy”库中的“create_engine”而不是“mysqldb.connect()”来访问数据库：

#relevant import:
from sqlalchemy import create_engine

#accessing database:
engine = create_engine("mysql://root:PASSWORD@host/database_name")
con = engine.connect()

#uploading dataframe to database:
df.to_sql(con=con, name='final_table', if_exists='replace', chunksize=10000)

【参考方案2】：

对我来说，您的数据中似乎有空值。在调用 .to_sql() 之前尝试填充数据框中的空值

df_final.fillna('default string')

或者删除空行

df_final.dropna(inplace=True)