Pyodbc 变量查询

Posted 2023-05-07

【中文标题】Pyodbc 变量查询

【英文标题】：Pyodbc variable query

【发布时间】：2018-10-16 20:41:58

【问题描述】：

我正在尝试使用变量进行查询，但字符串变量不起作用。我应该如何格式化查询中的变量 PrimaryAxis 和 SecondaryAxis？我使用了来自https://github.com/mkleehammer/pyodbc/wiki/Getting-started#parameters 的参考，页面上使用了单引号。我尝试了单引号和双引号，但没有运气。

import pyodbc

# Connect to database
conn_str = (
    r'DRIVER=Microsoft Access Driver (*.mdb, *.accdb);'
    r'DBQ=C:\Temp\TestDB.accdb;'
    r'Uid=;'
    r'Pwd=;'
    )

# Make cursor
connection = pyodbc.connect(conn_str)
connection.setencoding('utf-8')
cursor = connection.cursor()

# Create test table
cursor.execute("CREATE TABLE Coordinates (ID integer, X integer, Y integer)")
connection.commit()

# Create test data (Error "Missing semicolon (;)" if multiple values in one insert, thats why multiple insertions... not the main question)
cursor.execute("INSERT INTO Coordinates (ID, X, Y) VALUES (1,10,10);")
cursor.execute("INSERT INTO Coordinates (ID, X, Y) VALUES (2,20,10);")
cursor.execute("INSERT INTO Coordinates (ID, X, Y) VALUES (3,30,10);")
connection.commit()

# Filter parameters
Line = 10
Start = 10
End = 30

# Works
cursor.execute(r"""
                SELECT *
                FROM Coordinates
                WHERE Y = ? AND X BETWEEN ? AND ? """, Line, Start, End )

rows = cursor.fetchall()
for row in rows:
    print(row)

# does not work - main question
PrimaryAxis = 'X'
SecondaryAxis = 'Y'

cursor.execute(r"""
                SELECT *
                FROM Coordinates
                WHERE ? = ? AND ? BETWEEN ? AND ? """, SecondaryAxis, Line, PrimaryAxis, Start, End )

rows = cursor.fetchall()
for row in rows:
    print(row)

【参考方案1】：

您可以简单地使用数据库占位符：

# Filter parameters
line = 10
start = 10
end = 30
primary_axis = "X"
secondary_axis = "Y"
query = """
        SELECT *
        FROM Coordinates
        WHERE ? = ? AND ? BETWEEN ? AND ?
        """
cursor.execute(query, (secondary_axis, line, primary_axis, start, end))
... 

【讨论】：

@Steve 谢谢我更新了解决方案以防止基于bobby-tables.com/python的攻击

实际上，现在我再次阅读问题，由于引号，这将不起作用，这就是问题的原因。我试图删除我的答案，但没有运气。稍后我会尝试提出正确的解决方案。