mybatis传入map参数，map中包含list(输入参数)

我不是女神ヾ 2021-12-12 13:49 430阅读 0赞

**1.xml中配置:**

![复制代码][copycode.gif]

<select id="getQuestionsIdsForExamPaper" resultType="java.lang.String"
            parameterType="hashmap">
            select
            questionId from questions
            <where>
                <include refid="query_questionIds_where"></include>
            </where>
        </select>
    
        
        <sql id="query_questionIds_where">
            <if test="type!=null">
                and type=#{type}
            </if>
            <if test="level!=null">
                and level=#{level}
            </if>
            
            <if test="konwledges!=null and konwledges.size>0">
                and knowledgeType in
                <foreach collection="konwledges" item="knowledge" separator=","
                    open="(" close=")">
                    #{knowledge}
                </foreach>
            </if>
            <if test="num!=null">
                ORDER BY RAND() LIMIT #{num}
            </if>
        </sql>

![复制代码][copycode.gif]

2.Java测试:

![复制代码][copycode.gif]

// 测试查询ID集合
        @Test
        public void test3() throws SQLException {
            Map<String, Object> condition = new HashMap<String, Object>();
            condition.put("type", "单选题");
            condition.put("level", 1);
            condition.put("num", 3);
            List<String> konwledges = new ArrayList<String>();
            konwledges.add("安全生产管理知识");
            konwledges.add("电力安全规程制度");
            condition.put("num", 3);
            condition.put("konwledges", konwledges);
            List<String> IDs = questionsCustomMapper.getQuestionsIdsForExamPaper(condition);
            System.out.println(IDs.size());
        }

![复制代码][copycode.gif]

结果:![20190711143748345.png][]

总结:

map中的list同普通的一样，只是在遍历的时候collection要写出map中的List的键值。如:

![20190711143748367.png][]

**【当你用心写完每一篇博客之后,你会发现它比你用代码实现功能更有成就感!】**

[copycode.gif]: /images/20211211/7de3ca73f91145f2bc61bef537486301.png
[20190711143748345.png]: /images/20211211/cb3bf1c2612f4edba338e3dd79339abe.png
[20190711143748367.png]: /images/20211211/c3d4001f54b24091b58821554d9a09f4.png