如何将数据从 csv 插入数据库？我收到多个错误 (python)答案

【问题标题】：How can I insert data from csv to database? I'm getting multiple errors (python)如何将数据从 csv 插入数据库？我收到多个错误 (python)
【发布时间】：2023-01-10 10:14:12
【问题描述】：

这是我的完整代码。

import cx_Oracle, pandas as pd

connstr="spark/pass@localhost:1521/orcl"
conn = cx_Oracle.connect(connstr)
curs = conn.cursor()

csv = pd.read_csv('C:/Users/user/Downloads/products.csv')
lst = csv.values.tolist()
t = tuple(lst)

#Here where I tried to insert values to DB
curs.executemany("INSERT INTO PRODUCTS(number, date, code, price) VALUES(?, ?, ?, ?)", lst)
curs.commit()
curs.exit()

#Output
ORA-01036: illegal variable name/number

我尝试以不同的方式执行，好吧，当我第一次使用 python 插入表单时，这个想法很简单，但没有得到它。

d = input("<value>: "), int(input('<value2>: '))
s = f"INSERT INTO <table-name>(column1, column2) VALUES {d}"
curs.execute(s)
conn.commit()

W1，在这里我尝试应用我学到的东西

e = f"INSERT INTO PRODUCTS(number, date, code, price) VALUES {lst}"
curs.executemany(e)

#Output
TypeError: function missing required argument 'parameters' (pos 2)

e = "INSERT INTO PRODUCTS(number, date, code, price) VALUES(?, ?, ?, ?)"
curs.executemany(e, lst)

#Output
ORA-01036: illegal variable name/number

e = "INSERT INTO PRODUCTS(number, date, code, price) VALUES(?, ?, ?, ?)"
curs.executemany(e, csv)

#Output
ORA-01036: illegal variable name/number

W4,

curs.executemany("INSERT INTO PRODUCTS(number, date, code, price) VALUES(?, ?, ?, ?)", lst)
#Output
ORA-01036: illegal variable name/number

for r in csv: # Iterate through csv
    curs.execute("INSERT INTO PRODUCTS(number, date, code, price) VALUES (%s, %s, %s, %s)", *r)

#Output, also tried with (?, ?, ?, ?)
TypeError: function takes at most 2 arguments (7 given)

curs.executemany("INSERT INTO PRODUCTS(number, date, code, price) VALUES(?, ?, ?, ?)", t)

#Output
TypeError: parameters should be a list of sequences/dictionaries or an integer specifying the number of times to execute the statement

【问题讨论】：

你能告诉我们 t 的输出吗？

标签： python pandas oracle

【解决方案1】：

为什么要将列表转换为元组？能不能直接把列表传给executemany方法：

curs.executemany("""INSERT INTO PRODUCTS(number, date, code, price) VALUES(:1, :2, :3, :4)""", lst)

另请注意我是如何指代参数的（:1、:2 等）

【讨论】：

【解决方案2】：

Oracle Python 驱动程序文档有一个从 CSV 加载的完整示例，请参阅Loading CSV Files into Oracle Database：

import oracledb
import csv

# CSV file
FILE_NAME = 'data.csv'

# Adjust the number of rows to be inserted in each iteration
# to meet your memory and performance requirements
BATCH_SIZE = 10000

connection = oracledb.connect(user="hr", password=userpwd,
                              dsn="dbhost.example.com/orclpdb")

with connection.cursor() as cursor:

    # Predefine the memory areas to match the table definition.
    # This can improve performance by avoiding memory reallocations.
    # Here, one parameter is passed for each of the columns.
    # "None" is used for the ID column, since the size of NUMBER isn't
    # variable.  The "25" matches the maximum expected data size for the
    # NAME column
    cursor.setinputsizes(None, 25)

    with open(FILE_NAME, 'r') as csv_file:
        csv_reader = csv.reader(csv_file, delimiter=',')
        sql = "insert into test (id, name) values (:1, :2)"
        data = []
        for line in csv_reader:
            data.append((line[0], line[1]))
            if len(data) % BATCH_SIZE == 0:
                cursor.executemany(sql, data)
                data = []
        if data:
            cursor.executemany(sql, data)
        connection.commit()

【讨论】：