Python SQL executemany 语句不起作用

Question

我正在尝试执行一个删除语句来检查 table 是否有数据帧的 SKU 列中存在的任何 SKU。如果是，它会删除该行。

supplier_name = input("Enter supplier name of the supplier you are updating: ")
df = pd.read_csv("update.csv",sep=',')
cursor = mydb.cursor()
column = df["SKU"]
print(column)
query="""DELETE FROM price_calculations1(Supplier_Name, SKU) VALUES(?,?)"""
cursor.executemany(query,(supplier_name, column))
mydb.commit()
cursor.close()

将代码更改为；

cursor = mydb.cursor()
column = df["SKU"]
print(column)
query="""DELETE FROM price_calculations1 WHERE Supplier_Name=? AND SKU=?"""
cursor.executemany(query,(supplier_name, column))
mydb.commit()
cursor.close()

它给我以下错误：

mysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(Supplier_Name, SKU) VALUES(?,?)' at line 1 mysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '? AND SKU=?' at line 1

Answer 1

这不是 delete 语句的正确语法。

更多细节可以参考文档：https://dev.mysql.com/doc/refman/8.0/en/delete.html

正确的语法是：

DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name [[AS] tbl_alias]
    [PARTITION (partition_name [, partition_name] ...)]
    [WHERE where_condition]
    [ORDER BY ...]
    [LIMIT row_count]

在您的情况下，您的陈述应如下所示：

DELETE FROM price_calculations1
WHERE Supplier_Name=%s
AND SKU=%s

要使用参数化语句（也称为准备语句），您必须按如下方式创建游标：

cursor = mydb.cursor(prepared=True)

另请注意，executemany 需要可迭代对象的可迭代对象（或“序列或参数”），而 supplier_name 只是一个字符串，因此您也必须更改它。

文档中的 executemany 示例：

data = [
  ('Jane', date(2005, 2, 12)),
  ('Joe', date(2006, 5, 23)),
  ('John', date(2010, 10, 3)),
]
stmt = "INSERT INTO employees (first_name, hire_date) VALUES (%s, %s)"
cursor.executemany(stmt, data)

来源：https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-executemany.html

Python SQL executemany 语句不起作用

Python SQL executemany statement doesn't work

python

mysql

executemany