440
Mybatis傳參總結
mybatis中手動寫sql，步驟是先在navicate中執行通過的sql，
如果是對象類型傳參，需要注意jdbcType轉換，比如：name = #{record.name,jdbcType=VARCHAR}
以下幾種方法比較常用，歡迎補充。
1.pom.xml中mybatis依賴1.2.0
<dependencies>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.2.0</version>
<exclusions>
<exclusion>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.zaxxer</groupId>
<artifactId>HikariCP</artifactId>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
</plugin>
</plugins>
</build>
2.基本類型和對象參數，可以是這樣：
ServerMapper.java:
int updateByExample(@Param("record") Server record, @Param("example") ServerExample example);
ServerMapper.xml:
<update parameterType="map">
update server
set id = #{record.id,jdbcType=VARCHAR},
name = #{record.name,jdbcType=VARCHAR},
operatingsystem = #{record.operatingsystem,jdbcType=VARCHAR},
cpu = #{record.cpu,jdbcType=INTEGER},
applicant = #{record.applicant,jdbcType=VARCHAR},
status = #{record.status,jdbcType=VARCHAR}
<if test="_parameter != null">
<include ref />
</if>
</update>
3.僅有一個list參數，可以這樣：
ServerMapper.java:
List<ServerDetails> selectByServerIds(List<String> serverIds);
ServerMapper.xml，注意collection為:
<select resultMap="ServerDetailsMap">
SELECT s.id, s.`name`,s.operatingsystem,s.cpu,s.disksize,s.memorysize,s.intranetip,s.vcluster,s.`owner`,s.environment,s.applicant,s.`status`,
ip.ip,ip.`status` as ipstatus, ip.segment,ip.remark,ip.line
from `server` as s , ippool as ip
where s.intranetip = ip.id
and s.id in
<foreach item="item" collection="list" open="(" separator="," close=")">
#{item}
</foreach>
</select>
可以傳遞一個 List 實例或者數組作為參數對象傳給 MyBatis。
當你這麼做的時,MyBatis 會自動將它包裝在一個 Map 中,用名稱作為key。List 實例將會以“” 作為key,而數組實例將會以“”作為key。
4.多個參數中包含list的情況，是這樣的（excRelatedServerIds是list類型）：
ServerMapper.java文件中傳入的是包含list的map，ServerMapper.xml中的collection為
Map<String, Object> map = Maps.newHashMap();
map.put("env", env);
map.put("userId", userId);
map.put("excRelatedServerIds", excRelatedServerIds);
PageInfo<UserServerDetails> pageInfo = PageHelper.startPage(pageNum, pageSize).doSelectPageInfo(()-> serverMapper.selectPageByEnvAndUserExcRelated(map));
ServerMapper.xml：
select us.id, us.user_id, us.server_id,
s.`name`, s.operatingsystem, s.cpu,s.disksize,s.memorysize, s.intranetip, s.vcluster,s.`owner`,s.environment,s.applicant,s.`status`,
ip.ip,ip.`status` as ipstatus,ip.segment,ip.remark , ip.line
from user_server as us,`server` as s, ippool as ip
where us.server_id = s.id and s.intranetip = ip.id
<if test="env != null">
and s.environment=#{env,jdbcType=INTEGER}
</if>
<if test="userId != null">
and us.user_id=#{userId,jdbcType=VARCHAR}
</if>
and s.id not in
<foreach item="item" index="index" collection="excRelatedServerIds" open="(" separator="," close=")">
#{item}
</foreach>
</select>
5.還有一種是按照順序傳參數，這種不推薦：
Mapper.java：
Public User selectUser(String name,String area);
Mapper.xml ：
<select id="selectUser" resultMap="BaseResultMap">
select * from user_user_t where user_name = #{0} and user_area=#{1}
</select>
其中，#{0}代表接收的是dao層中的第一個參數，#{1}代表dao層中第二參數，更多參數一致往後加即可。
6.如果要封裝自己的返回類型，需要xml文件中定義並且去引用bean對象：
<resultMap type="com.ServerDetails">
<id column="id" property="id" jdbcType="VARCHAR" />
<result column="name" jdbcType="VARCHAR" property="name" />
<result column="operatingsystem" jdbcType="VARCHAR" property="operatingsystem" />
<result column="cpu" jdbcType="INTEGER" property="cpu" />
<result column="disksize" jdbcType="INTEGER" property="disksize" />
<result column="memorysize" jdbcType="INTEGER" property="memorysize" />
<result column="intranetip" jdbcType="VARCHAR" property="intranetip" />
<result column="vcluster" jdbcType="VARCHAR" property="vcluster" />
<result column="owner" jdbcType="VARCHAR" property="owner" />
<result column="environment" jdbcType="INTEGER" property="environment" />
<result column="applicant" jdbcType="VARCHAR" property="applicant" />
<result column="status" jdbcType="VARCHAR" property="status" />
</resultMap>
參考：https://blog.csdn.net/u014687389/article/details/72778664?locationNum=8&fps=1
最後更新：2017-08-13 22:43:16