【问题标题】:Pyodbc variable queryPyodbc 变量查询
【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 PrimaryAxisSecondaryAxis?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)

【问题讨论】:

    标签: python ms-access pyodbc


    【解决方案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。
    猜你喜欢
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    相关资源
    最近更新 更多