Python：在python中使用executemany（）批量上传Oracle表的记录

Posted 2023-03-23

【中文标题】Python：在python中使用executemany（）批量上传Oracle表的记录

【英文标题】：Python: Bulk upload records of Oracle table with executemany() in python

【发布时间】：2020-10-22 22:09:07

【问题描述】：

  data=[]
  dataToInsert = [ ]
  for index, row in df.iterrows():
   contentid = row['CONTENTID']
   Objectsummary = row['OBJECT_SUMMARY']
   Title=row['TITLE']
   if Title is None:
    Title = ""
   if Objectsummary is None:
    Objectsummary = ""
   allSummeries =Title  + ' ' + Objectsummary
   lists=function_togetNounsAndVerbs(allSummeries)
   verbList =lists[0]
   nounList =lists[1]

   NounSet = set(nounList)
   VerbSet = set(verbList)

   verbs = " "
   verbs=verbs.join(VerbSet)

   nouns=" "
   nouns=nouns.join(NounSet)
   verbs=re.sub(r" ", ", ", verbs)
   nouns=re.sub(r" ", ", ", nouns)
 
  # Here we are going to create the data sdet to be updated in database table in batch form.
   data.append(nouns)
   data.append(verbs)
   data.append('PROCESSED')
   data.append(contentid)
   dataToInsert.append([data[0],  data[1], data[2], data[3]])

  print("ALL DATA TO BE UPDATED IN TABLE IS :---> ",dataToInsert)
  statement = """UPDATE test_batch_update_python SET NOUNS = ?, Verbs = ?  where CONTENTID = ?"""
  a = cursor.executemany(statement, dataToInsert)
  connection.commit()

在上面的代码中 function_togetNounsAndVerbs(allSummeries) 这个函数将返回列表。 我收到以下异常：

 **a = cursor.executemany(statement, dataToInsert)
cx_Oracle.DatabaseError: ORA-01036: illegal variable name/number**

请帮我解决这个问题。 或者我还有什么其他方法可以做到这一点。最初，我曾经使用 cursor.execute() 一次更新单行，但这非常耗时。为了尽量减少我使用批量上传的时间（即 cursor.executemany() ）

【问题讨论】：

您的查询中有 3 个占位符：UPDATE test_batch_update_python SET NOUNS = ?, Verbs = ? where CONTENTID = ?，但您将 4 个项目附加到 data。要么您错过了查询中的一列，要么您需要删除'PROCESSED'。

使用 Oracle，您需要使用 ":name" 而不是 "?"用于 SQL 语句中的绑定占位符。检查 cx_Oracle 文档 Batch Statement Execution and Bulk Loading 和 Using Bind Variables。

【参考方案1】：

这是一个有效的相关示例。该表创建为：

DROP table test_batch_update_python;
CREATE TABLE test_batch_update_python (contentid NUMBER, nouns VARCHAR2(20), verbs VARCHAR2(20));
INSERT INTO test_batch_update_python (contentid) VALUES (1);
INSERT INTO test_batch_update_python (contentid) VALUES (2);
COMMIT;

cursor = connection.cursor()

dataToInsert = [
       ('shilpa', 'really fast', 1),
       ('venkat', 'also really fast', 2),
   ]

print("ALL DATA TO BE UPDATED IN TABLE IS :---> ", dataToInsert)

connection.autocommit = True;
statement = """UPDATE test_batch_update_python SET nouns=:1, verbs=:2 WHERE contentid=:3"""
cursor.setinputsizes(20, 20, None)
cursor.executemany(statement, dataToInsert)

输出是：

ALL DATA TO BE UPDATED IN TABLE IS :--->  [('shilpa', 'really fast', 1), ('venkat', 'also really fast', 2)]

然后查询数据给出：

SQL> select * from test_batch_update_python;

 CONTENTID NOUNS                VERBS
---------- -------------------- --------------------
         1 shilpa               really fast
         2 venkat               also really fast

【参考方案2】：

检查此链接以获取更新声明

https://blogs.oracle.com/oraclemagazine/perform-basic-crud-operations-with-cx-oracle-part-3

谢谢