将变量放入sql查询中

import pymysql

# 假设有一个变量name需要放入查询中
name = "John"

# 连接数据库
conn = pymysql.connect(host='localhost', user='root', password='password', db='mydb')
cursor = conn.cursor()

# 执行参数化查询
sql = "SELECT * FROM users WHERE name = %s"
cursor.execute(sql, (name,))

# 获取查询结果
result = cursor.fetchall()

# 关闭数据库连接
cursor.close()
conn.close()

import java.sql.*;

public class Main {
    public static void main(String[] args) {
        // 假设有一个变量name需要放入查询中
        String name = "John";

        // 连接数据库
        String url = "jdbc:mysql://localhost/mydb";
        String username = "root";
        String password = "password";
        try (Connection conn = DriverManager.getConnection(url, username, password);
             Statement stmt = conn.createStatement()) {

            // 执行查询
            String sql = "SELECT * FROM users WHERE name = '" + name + "'";
            ResultSet rs = stmt.executeQuery(sql);

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