{"id":1992,"date":"2017-06-15T21:09:59","date_gmt":"2017-06-15T13:09:59","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=1992"},"modified":"2026-08-18T11:23:02","modified_gmt":"2026-08-18T03:23:02","slug":"mybatis%e5%a4%9a%e8%a1%a8%e5%85%b3%e8%81%94%e6%9f%a5%e8%af%a2%e4%b9%8b%e5%a4%9a%e5%af%b9%e5%a4%9a","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=1992","title":{"rendered":"Mybatis\u591a\u8868\u5173\u8054\u67e5\u8be2\u4e4b\u591a\u5bf9\u591a"},"content":{"rendered":"
\n

MyBatis \u591a\u8868\u5173\u8054\u5206\u6210\u56db\u79cd\uff1a\u4e00\u5bf9\u4e00\u3001\u4e00\u5bf9\u591a\u3001\u591a\u5bf9\u4e00\u3001\u591a\u5bf9\u591a\u3002\u6620\u5c04\u5173\u952e\u4ecd\u662f resultMap<\/code>\uff0c\u53ef\u53c2\u8003 MyBatis\u5b66\u4e60 \u4e4b \u4e8c\u3001SQL\u8bed\u53e5\u6620\u5c04\u6587\u4ef6(1)resultMap<\/a>\u3002\u672c\u6587\u53ea\u505a\u591a\u5bf9\u591a<\/strong>\uff1a\u5b66\u751f\u548c\u8bfe\u7a0b\u5f7c\u6b64\u6ca1\u6709\u5916\u952e\uff0c\u4e2d\u95f4\u8868 t_stu_cou<\/code> \u7528 in<\/code> \u67e5\u51fa\u53e6\u4e00\u4fa7 id \u5217\u8868\u3002<\/p>\n

\u5c5e\u6027\u7c7b\u578b\u662f\u96c6\u5408\u7528 collection<\/code>\uff0c\u662f\u5355\u4e2a\u5bf9\u8c61\u7528 association<\/code>\u3002\u9ed8\u8ba4 TypeAliasRegistry \u5df2\u6302\u4e0a JDK \u5e38\u7528\u7c7b\uff0c\u6240\u4ee5 javaType=\"java.lang.Integer\"<\/code> \u4e5f\u53ef\u5199\u6210 javaType=\"Integer\"<\/code>\u3002<\/p>\n

\u4e00\u3001\u8868\u7ed3\u6784\u4e0e\u7c7b\u7ed3\u6784<\/h2>\n

\u8868\u7ed3\u6784<\/h3>\n

\"\"<\/a><\/p>\n

\u7c7b\u7ed3\u6784<\/h3>\n

\"\"<\/a><\/p>\n\n\n\n\n\n\n\n\n
\u67e5\u8be2<\/th>\nresultMap<\/th>\n\u662f\u5426\u5e26\u53e6\u4e00\u4fa7<\/th>\n<\/tr>\n<\/thead>\n
findCouById<\/code><\/td>\ncoursesMap<\/code><\/td>\n\u53ea\u67e5\u8bfe\u7a0b<\/td>\n<\/tr>\n
findCouAndStu<\/code><\/td>\ncouAndStu<\/code><\/td>\n\u8bfe\u7a0b + \u9009\u4fee\u5b66\u751f<\/td>\n<\/tr>\n
findStuById<\/code><\/td>\nstudentMap<\/code><\/td>\n\u53ea\u67e5\u5b66\u751f<\/td>\n<\/tr>\n
findStuAndCou<\/code><\/td>\nstudentAndCourses<\/code><\/td>\n\u5b66\u751f + \u9009\u4fee\u8bfe\u7a0b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e8c\u3001CoursesMapper.xml<\/h2>\n

\u6309\u8bfe\u7a0b id \u67e5\u5b66\u751f\u65f6\uff0c\u5b66\u751f id \u4e0d\u662f\u5355\u503c\uff0c\u8981\u7528\u4e2d\u95f4\u8868 fk_cou_id<\/code> \u53d6\u51fa fk_stu_id<\/code>\uff0cSQL \u91cc\u5199 in<\/code>\u3002<\/p>\n

<mapper namespace=\"com.ittx.mybatis.demo1.dao.CoursesDao\">\n    <resultMap type=\"com.ittx.mybatis.demo1.model.Courses\"\n        id=\"coursesMap\">\n        <!-- \u9ed8\u8ba4 TypeAliasRegistry \u4f1a\u6302\u4e0a\u5f88\u591a JDK \u5e38\u7528\u7c7b\uff0cjavaType=\"java.lang.Integer\" \u53ef\u4ee5\u5199\u6210 javaType=\"Integer\" -->\n        <id property=\"id\" column=\"cid\" javaType=\"java.lang.Integer\" \/>\n        <result property=\"name\" column=\"courses_name\" javaType=\"java.lang.String\" \/>\n    <\/resultMap>\n\n    <resultMap type=\"com.ittx.mybatis.demo1.model.Courses\"\n        id=\"couAndStu\">\n        <id property=\"id\" column=\"cid\" javaType=\"java.lang.Integer\" \/>\n        <result property=\"name\" column=\"courses_name\" javaType=\"java.lang.String\" \/>\n\n        <!-- \u5c5e\u6027\u662f\u96c6\u5408\u7528 collection\uff0c\u5c5e\u6027\u662f\u7c7b\u7528 association -->\n        <collection property=\"student\" column=\"cid\"\n            select=\"findStudentByCourses\"><\/collection>\n    <\/resultMap>\n\n    <!-- \u5b66\u751f\u8868\u3001\u8bfe\u7a0b\u8868\u90fd\u6ca1\u6709\u5916\u952e\uff0c\u7528\u7b2c\u4e09\u5f20\u5173\u8054\u8868\uff1b\u6839\u636e fk_cou_id \u5f97\u5230\u5b66\u751f id\uff0c\u591a\u5bf9\u591a\u65f6 id \u4e0d\u662f\u5355\u503c\uff0c\u6570\u636e\u5e93\u91cc\u7528 in -->\n    <select id=\"findStudentByCourses\" resultMap=\"com.ittx.mybatis.demo1.dao.StudentDao.studentMap\">\n        select * from\n        t_student where sid in (select fk_stu_id from t_stu_cou where\n        fk_cou_id=#{id})\n    <\/select>\n    <!-- resultMap=\"coursesMap\" \u53ea\u6839\u636e\u8bfe\u7a0b id \u627e\u8bfe\u7a0b\uff0c\u4e0d\u5173\u8054\u9009\u4fee\u5b66\u751f -->\n    <select id=\"findCouById\" resultMap=\"coursesMap\">\n        select * from t_courses where\n        cid=#{id}\n    <\/select>\n    <!-- resultMap=\"couAndStu\" \u6839\u636e\u8bfe\u7a0b id \u627e\u8bfe\u7a0b\uff0c\u540c\u65f6\u5173\u8054\u67e5\u8be2\u9009\u4fee\u8be5\u8bfe\u7684\u5b66\u751f -->\n    <select id=\"findCouAndStu\" resultMap=\"couAndStu\">\n        select * from t_courses\n        where cid=#{id}\n    <\/select>\n<\/mapper><\/code><\/pre>\n
\u4e09\u3001StudentMapper.xml<\/h2>\n
\u4ece\u5b66\u751f\u51fa\u53d1\u67e5\u8bfe\u7a0b\uff0c\u5bf9\u79f0\u5730\u6309 fk_stu_id<\/code> \u53bb\u4e2d\u95f4\u8868\u53d6 fk_cou_id<\/code>\u3002<\/p>\n
<mapper namespace=\"com.ittx.mybatis.demo1.dao.StudentDao\">\n\n    <resultMap type=\"com.ittx.mybatis.demo1.model.Student\"\n        id=\"studentMap\">\n        <id property=\"id\" column=\"sid\" javaType=\"java.lang.Integer\" \/>\n        <result property=\"name\" column=\"student_name\" javaType=\"java.lang.String\" \/>\n    <\/resultMap>\n\n    <resultMap type=\"com.ittx.mybatis.demo1.model.Student\"\n        id=\"studentAndCourses\">\n        <id property=\"id\" column=\"sid\" javaType=\"java.lang.Integer\" \/>\n        <result property=\"name\" column=\"student_name\" javaType=\"java.lang.String\" \/>\n        <collection property=\"courses\" column=\"sid\"\n            select=\"findCoursesByStudent\"><\/collection>\n    <\/resultMap>\n\n    <select id=\"findCoursesByStudent\" resultMap=\"com.ittx.mybatis.demo1.dao.CoursesDao.coursesMap\">\n        select * from t_courses where cid in (select fk_cou_id from t_stu_cou where\n        fk_stu_id = #{id})\n    <\/select>\n    <!-- resultMap=\"studentMap\" \u53ea\u6839\u636e\u5b66\u751f id \u627e\u5b66\u751f\uff0c\u4e0d\u5173\u8054\u9009\u4fee\u8bfe\u7a0b -->\n    <select id=\"findStuById\" resultMap=\"studentMap\">\n        select * from t_student where sid = #{id}\n    <\/select>\n    <!-- resultMap=\"studentAndCourses\" \u6839\u636e\u5b66\u751f id \u627e\u5b66\u751f\uff0c\u540c\u65f6\u5173\u8054\u67e5\u8be2\u9009\u4fee\u8bfe\u7a0b -->\n    <select id=\"findStuAndCou\" resultMap=\"studentAndCourses\">\n        select * from t_student where sid = #{id}\n    <\/select>\n<\/mapper><\/code><\/pre>\n
\n
\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a\u591a\u5bf9\u591a\u6ca1\u6709\u76f4\u63a5\u5916\u952e\uff0c\u7528\u4e2d\u95f4\u8868 + collection \u7684\u5d4c\u5957 select\uff1b\u540c\u4e00\u5957 Mapper \u63d0\u4f9b\u300c\u53ea\u67e5\u81ea\u5df1\u300d\u548c\u300c\u5e26\u51fa\u5bf9\u4fa7\u96c6\u5408\u300d\u4e24\u5957 resultMap\uff0c\u907f\u514d\u6bcf\u6b21\u90fd N+1\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
MyBatis \u591a\u8868\u5173\u8054\u5206\u6210\u56db\u79cd\uff1a\u4e00\u5bf9\u4e00\u3001\u4e00\u5bf9\u591a\u3001\u591a\u5bf9\u4e00\u3001\u591a\u5bf9\u591a\u3002\u6620\u5c04\u5173\u952e\u4ecd\u662f resultMap\uff0c\u53ef\u53c2\u8003 M […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[92],"tags":[188],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1992"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1992"}],"version-history":[{"count":3,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1992\/revisions"}],"predecessor-version":[{"id":3552,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/1992\/revisions\/3552"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1992"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1992"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1992"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}