引言
SQL注入是一种常见的网络安全漏洞，它允许攻击者通过在数据库查询中注入恶意SQL代码来窃取、篡改或破坏数据。DVWA（Damn Vulnerable Web Application）是一个用于安全学习和测试的Web应用程序，其中包含了多个安全漏洞，包括SQL注入。本文将深入探讨DVWA中级SQL注入的实战技巧与防御策略。
一、DVWA中级SQL注入概述
在DVWA中，中级SQL注入通常涉及到更复杂的注入技巧，如联合查询、时间盲注、错误注入等。这些技巧要求攻击者对SQL语言和数据库结构有更深入的了解。
二、实战技巧
1. 联合查询
联合查询是SQL注入中的一种高级技巧，它允许攻击者通过在注入点添加额外的SQL语句来获取数据。以下是一个简单的联合查询示例：
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