将表中的列值传递到WHERE子句

import mysql.connector

# 连接数据库
cnx = mysql.connector.connect(user='username', password='password', host='localhost', database='database_name')

# 创建游标
cursor = cnx.cursor()

# 定义变量
column_value = 'some_value'

# 执行查询
query = "SELECT * FROM table_name WHERE column_name = %s"
cursor.execute(query, (column_value,))

# 获取结果
result = cursor.fetchall()

# 关闭游标和数据库连接
cursor.close()
cnx.close()

import java.sql.*;

public class Main {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/database_name";
        String username = "username";
        String password = "password";
        String columnValue = "some_value";

        try (Connection conn = DriverManager.getConnection(url, username, password);
             PreparedStatement stmt = conn.prepareStatement("SELECT * FROM table_name WHERE column_name = ?")) {

            stmt.setString(1, columnValue);
            ResultSet rs = stmt.executeQuery();

            while (rs.next()) {
                // 处理查询结果
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}