mybatis如何遍历Map的key和value_mybatis 怎么遍历hashmap键值对-优快云博客

本文链接：https://blog.youkuaiyun.com/Bzbtyhydcxy/article/details/104573065

本文详细介绍了使用MyBatis框架进行数据库操作的方法，包括动态SQL的编写技巧，如条件查询、插入、更新和删除操作。通过具体示例展示了如何利用Java Map集合和实体类进行参数传递，实现对数据库的高效操作。

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实例一：
Java代码：
SqlSession session = MyBatisConnectionFactory.getSession(“pg”);
HashMap<String, Object> params = new HashMap<>(); //传入的参数
params.put(“content”, tableContent);
params.put(“tableName”, tableName);
params.put(“seq”, seq);
int flag = session.delete(“deleteOne”, params); //删除记录
HashMap<String, Object> map = session.selectOne(“selectOne”, params); //查询记录是否存在
flag = session.update(“updateOne”, params) > 0 ? true : false; //更新
flag = session.insert(“insertOne”, params) > 0 ? true : false; //新增
xml：

select count(*) as num from ${tableName} where seq =
#{seq};

	    <!-- 1.1 插入一条数据 -->  
	    <insert id="insertOne" parameterType="java.util.Map">  
	        insert into ${tableName}  
	        <foreach collection="content.keys" item="key" open="(" close=")"  
	            separator=",">  
	            ${key}  
	        </foreach>  
	        values  
	        <foreach collection="content.values" item="value" open="("  
	            close=")" separator=",">  
	            #{value}  
	        </foreach>  
	    </insert>  
	  
	    <!-- 1.2 更新记录 -->  
	    <update id="updateOne" parameterType="java.util.Map">  
	        UPDATE ${tableName} SET  
	        <foreach collection="content.keys" item="key" open="" close=""  
	            separator=",">  
	            ${key} = #{content[${key}]}  
	        </foreach>  
	        where seq = #{content[seq]} and genius_uid <=  
	        #{content[genius_uid]};  
	    </update>  
	  
	    <!-- 1.3 删除无效数据 -->  
	    <delete id="deleteOne" parameterType="java.util.Map">  
	        delete from ${tableName}  
	        where seq = #{content[seq]};  
	    </delete>  
	</mapper>

实例二：
entity：
1.
@Data
public class LineInsertVo {
private String templateId;
private String tableName;
/**
* 任务制定人
/
private String assignMan;
/*
* 牵头单位
/
private String leadMan;
/*
* 参与单位
/
private String executeMen;
/*
* 表头信息
*/
private List lines;
}
2. @Data
@Table(name = “TASK_CONFIG_PLAN”)
public class TaskConfigPlanDo extends BaseEntity {
//表头信息存储
private transient Map<String,String> columnValue;
}
service:
TaskConfigPlanDo taskConfigPlanDo = new TaskConfigPlanDo();
Map<String, String> map = new HashMap<>();
for (LineVo vo : lines) {
if (vo.getIsTaskLine() == 0) {
String column = “HEAD_LINE” + vo.getId();
map.put(column, vo.getLineName());
}
}
dao:
void insertTaskConfs(@Param(“entity”) TaskConfigPlanDo taskConfigPlanDo, @Param(“tableName”) String tableName);
xml:

INSERT INTO ${tableName}
(
TASK_ID,
LEAD_MAN,
EXECUTE_MEN,
TEMPLATE_ID,

${key}

)
VALUES
(
#{entity.taskId,jdbcType=VARCHAR} ,
#{entity.leadMan,jdbcType=VARCHAR} ,
#{entity.executeMen,jdbcType=VARCHAR} ,
#{entity.templateId,jdbcType=VARCHAR},

#{value}

)