什么是 MyBatis ？
MyBatis 是支持定制化 SQL、存儲過程以及高級映射的優(yōu)秀的持久層框架。MyBatis 避免了幾乎所有的 JDBC 代碼和手動設置參數(shù)以及獲取結果集。MyBatis 可以對配置和原生Map使用簡單的 XML 或注解，將接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java對象)映射成數(shù)據(jù)庫中的記錄。
表：market_plan(營銷計劃(關聯(lián)了用戶))
market_plan_product(產品關聯(lián)營銷計劃)
market_plan_label(標簽關聯(lián)營銷計劃)
market_plan_ideadata(創(chuàng)意素材關聯(lián)營銷計劃)
user_ideadata_activity(活動關聯(lián)用戶，活動關聯(lián)創(chuàng)意素材表)
user(用戶表)
配置原則：A關聯(lián)B，將A的resultMap關聯(lián)(association)到B的resultMap中，這樣才能在寫關聯(lián)查詢sql語句的時候，查詢出A,B表中的屬性。多張表的關聯(lián)也是一樣的道理！
配置xml示例：
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<resultMap id="userResultMap" type="com.mchuan.fastmarketplat.b.entity.User"><id column="USER_ID" property="id" /><result column="ACCOUNT" property="account" /><result column="NAME" property="name" /><result column="MOBILE" property="mobile" /></resultMap><resultMap id="labelResultMap"type="com.mchuan.fastmarketplat.b.entity.MarketPlanLabel"><id property="id" column="LABEL_ID" /><result property="gender" column="GENDER" /><result property="area" column="AREA" /><result property="age" column="AGE" /><result property="deviceType" column="DEVICE_TYPE" /><result property="communicationFee" column="COMMUNICATION_FEE" /><result property="actionLabels" column="ACTION_LABELS" /><result property="netScene" column="NET_SCENE" /></resultMap><resultMap id="productResultMap"type="com.mchuan.fastmarketplat.b.entity.MarketPlanProduct"><id property="id" column="PRODUCT_ID" /><result property="coverAmount" column="COVER_AMOUNT" /></resultMap><resultMap id="activityResultMap"type="com.mchuan.fastmarketplat.b.entity.UserActivity"><id column="AC_ID" property="id" /><result column="ACTIVITY_ID" property="activityId" jdbcType="INTEGER" /><result column="COVER_URL" property="coverUrl" jdbcType="VARCHAR" /><result column="ACTIVITY_URL" property="activityUrl" jdbcType="VARCHAR" /><result column="VIEW_URL" property="viewUrl" jdbcType="VARCHAR" /><result column="CREATE_TIME" property="createTime" /><result column="UPDATE_TIME" property="updateTime" /></resultMap><resultMap id="ideaDataResultMap"type="com.mchuan.fastmarketplat.b.entity.MarketPlanIdeaData"><id property="id" column="IDEA_DATA_ID" /><result property="content" column="CONTENT" /><result property="linkUrl" column="LINK_URL" /><!-- ideaData關聯(lián)屬性 --><association property="userActivity"javaType="com.mchuan.fastmarketplat.b.entity.UserActivity" resultMap="activityResultMap" /></resultMap><resultMap id="BaseResultMap" type="com.mchuan.fastmarketplat.b.entity.MarketPlan"><id column="ID" property="id" jdbcType="INTEGER" /><result column="PLAN_NAME" property="planName" jdbcType="VARCHAR" /><result column="BUDGET" property="budget" jdbcType="DECIMAL" /><result column="ACTUAL_BUDGET" property="actualBudget"jdbcType="DECIMAL" /><result column="DEMAND_TYPE" property="demandType" jdbcType="VARCHAR" /><result column="START_DATE" property="startDate" /><result column="END_DATE" property="endDate" /><result column="CREATE_STATUS" property="createStatus"jdbcType="INTEGER" /><result column="CREATE_TIME" property="createTime" /><result column="UPDATE_TIME" property="updateTime" /><result column="NOTE" property="note" jdbcType="VARCHAR" /><result column="STATUS" property="status" jdbcType="INTEGER" /><result column="DESTPAGE_URL" property="destpageUrl" jdbcType="VARCHAR" /><result column="IS_AWARD" property="isAward" jdbcType="INTEGER" /><result column="AWARD_MONEY" property="awardMoney" jdbcType="DECIMAL" /><result column="ADVERTISER" property="advertiser" jdbcType="VARCHAR" /><result column="INDUSTRY" property="industry" jdbcType="INTEGER" /> |
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<!-- marketPlan關聯(lián)屬性 --><association property="user"javaType="com.mchuan.fastmarketplat.b.entity.User" resultMap="userResultMap" /><association property="marketPlanLabel"javaType="com.mchuan.fastmarketplat.b.entity.MarketPlanLabel"resultMap="labelResultMap" /><association property="marketPlanProduct"javaType="com.mchuan.fastmarketplat.b.entity.MarketPlanProduct"resultMap="productResultMap" /><association property="marketPlanIdeaData"javaType="com.mchuan.fastmarketplat.b.entity.MarketPlanIdeaData"resultMap="ideaDataResultMap" /></resultMap> |
以上所述是小編給大家介紹的 Mybatis 中的一對一，一對多，多對多的配置原則示例代碼，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對服務器之家網(wǎng)站的支持！
原文鏈接：http://blog.csdn.net/qq_32071077/article/details/59483589
