将 clob 转换为 varchar python

Question

我有这段代码来创建表并将数据导入 Oracle 数据库

# Connect to DB
conn = connect_to_oracle(user_db, pw_db)
connection = conn.raw_connection()
cursor = connection.cursor()

# Setting Param
test = pd.read_csv(r"template.csv",
                   dtype={'updated_date':'str'})

cursor.execute('''
CREATE TABLE customers_test
( updated_date VARCHAR2(100) NOT NULL,
  id_1 VARCHAR2(100) NOT NULL,
  id_2 VARCHAR2(100) NOT NULL,
  type VARCHAR2(10) NOT NULL,
  score float(10) NOT NULL,
  lvl VARCHAR2(10) NOT NULL,
  sgmt VARCHAR2(10))
''')

之后我使用 to_sql 函数导入数据

test.to_sql('CUSTOMER_TEST', engine, schema, if_exists='append', index=False)

但是，当我检查 DB 时，我发现几乎所有的列都变成了 CLOB

UPDATED_DATE, CLOB
ID_1, CLOB
ID_2, CLOB
TYPE, CLOB
SCORE, FLOAT
LVL, CLOB
SGMT, CLOB

所以我想知道如何将所有列转换为 varchar2？如何防止它们变成 CLOB？谢谢

Answer 1

在正常情况下，代码应该可以正常工作

Python 示例代码

import cx_Oracle

host="ODCGRC1R.SCGER.DEV.CORP"
port=60995
sid='odcgrc1r'
user='CPL_REP'
password='Cpl3_r3p'
sid = cx_Oracle.makedsn(host, port, service_name=sid)

connection = cx_Oracle.connect(user, password, sid, encoding="UTF-8")
cursor = connection.cursor()
cursor.execute('''
CREATE TABLE customers_test
( updated_date VARCHAR2(100) NOT NULL,
  id_1 VARCHAR2(100) NOT NULL,
  id_2 VARCHAR2(100) NOT NULL,
  type VARCHAR2(10) NOT NULL,
  score float(10) NOT NULL,
  lvl VARCHAR2(10) NOT NULL,
  sgmt VARCHAR2(10))
''')

现在我对我的数据库执行 tnsping，运行 python 代码并通过sqlplus 连接以验证表结构

C:\python>tnsping ODCGRC1R.SCGER.DEV.CORP:60995/odcgrc1r

TNS Ping Utility for 32-bit Windows: Version 11.2.0.1.0 - Production on 29-SEP-2021 10:51:34

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

Parameterdateien benutzt:
C:\Programme\Oracle\11.2.0\client\network\admin\sqlnet.ora

Adapter HOSTNAME zur Aufl÷sung des Alias benutzt
Verbindungsversuch mit (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=odcgrc1r))(ADDRESS=(PROTOCOL=TCP)(HOST=180.22.128.47)(PORT=60995)))
OK (140 ms)

C:\python> C:\python>tnsping ODCGRC1R.SCGER.DEV.CORP:60995/odcgrc1r

TNS Ping Utility for 32-bit Windows: Version 11.2.0.1.0 - Production on 29-SEP-2021 10:51:34

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

Parameterdateien benutzt:
C:\Programme\Oracle\11.2.0\client\network\admin\sqlnet.ora

Adapter HOSTNAME zur Aufl÷sung des Alias benutzt
Verbindungsversuch mit (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=odcgrc1r))(ADDRESS=(PROTOCOL=TCP)(HOST=180.22.128.47)(PORT=60995)))
OK (140 ms)

C:\python> python testconn.py

C:\python>sqlplus cpl_rep/Cpl3_r3p@//ODCGRC1R.SCGER.DEV.CORP:60995/odcgrc1r

SQL*Plus: Release 12.2.0.1.0 Production on Wed Sep 29 10:52:48 2021

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Last Successful login time: Wed Sep 29 2021 10:47:26 +02:00

Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production

SQL> desc cpl_rep.customers_test
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 UPDATED_DATE                              NOT NULL VARCHAR2(100)
 ID_1                                      NOT NULL VARCHAR2(100)
 ID_2                                      NOT NULL VARCHAR2(100)
 TYPE                                      NOT NULL VARCHAR2(10)
 SCORE                                     NOT NULL FLOAT(10)
 LVL                                       NOT NULL VARCHAR2(10)
 SGMT                                               VARCHAR2(10)

但是如果你没有在to_sql 函数中指定正确的dtype，你可以得到这个行为，正如问题的海报所说的那样。