Question

如何将数据库中的数据单行输出到csv文件？现在看起来像这样：

ID
SN
CLASS_ID

我需要为：

ID SN CLASS_ID

到目前为止，我的代码：

path = "C:\IBSO\DOK\exercise_1.csv"
try:
    connection = cx_Oracle.connect("admin", "123", "localhost")
except cx_Oracle.DatabaseError as err:
    print("Error auth", err)
cursor = connection.cursor()
cursor.execute("""
    SELECT * FROM Z#PRODUCT
    WHERE ROWNUM <=10
    """)
with open(path, 'w', newline='') as csvfile:
     writer = csv.writer(csvfile, delimiter=' ')
     for column in cursor.description:
        writer.writerow(''.join(column[0]))

Answer 1

您可以使用pandas.read_sql(conn, query)将SQL读入pandas.DataFrame，然后使用pandas.to_csv(path)保存到文件

因此代码将类似于：

import pandas as pd 
path = "C:\IBSO\DOK\exercise_1.csv"
try:
    connection = cx_Oracle.connect("admin", "123", "localhost")
except cx_Oracle.DatabaseError as err:
    print("Error auth", err)
query = """
        SELECT * FROM Z#PRODUCT
        WHERE ROWNUM <=10
        """
df = pd.read_sql(connection, query)
df.to_csv(path, index= False)

从理论上讲，您可以将其单行插入：pd.read_sql(connection, query).to_csv(path, index= False)，但我尚未对此进行测试。

Answer 2

问题出在

for column in cursor.description:
    writer.writerow(''.join(column[0]))

我假设每个column是一个字符串，因此对于每个column，您将用空字符串写出列名中各个字符的连接结果，例如：

In [58]: ''.join('asdfe')                                                                 
Out[58]: 'asdfe'

并使用writerow，然后在单个行上放置一个列名。

您想要做的是将工作留在writerow上，该工作旨在将CSV（不正确地说）中包含的值放入CSV中：

with open(path, 'w', newline='') as csvfile:
     writer = csv.writer(csvfile, delimiter=' ')

     writer.writerow(cursor.description)
     # other code where you process and output the query results

将数据单行输出到csv文件

2 个答案: