{"id":240,"date":"2021-09-27T23:35:32","date_gmt":"2021-09-27T15:35:32","guid":{"rendered":"http:\/\/qqiuklele.cn\/?p=240"},"modified":"2025-03-26T15:19:44","modified_gmt":"2025-03-26T07:19:44","slug":"mybatis%e5%a4%9a%e8%a1%a8%e8%81%94%e5%90%88%e6%9f%a5%e8%af%a2","status":"publish","type":"post","link":"https:\/\/qqiukulele.cn\/?p=240","title":{"rendered":"Mybatis\u591a\u8868\u8054\u5408\u67e5\u8be2"},"content":{"rendered":"\n

\u8868\u4e0e\u8868\u4e4b\u95f4\u7684\u5173\u7cfb\u53ef\u4ee5\u5206\u4e3a\u4e09\u79cd\uff1a1-1\u30011-N\u3001N-N\u3002\u90a3\u4e48\u6211\u5c06\u7528\u5f3a\u5927\u7684mybatis\u6f14\u793a\u548c\u603b\u7ed3\u4e00\u4e0b\u8fd9\u4e00\u5bf9\u591a<\/code>\u548c\u591a\u5bf9\u591a<\/code>\u7684\u5173\u7cfb\u7684\u67e5\u8be2\uff0c\u4e14\u5206\u522b\u7528\u4e24\u6b65\u67e5\u8be2\u65b9\u6cd5\u548c\u8fde\u63a5\u67e5\u8be2\u65b9\u6cd5\uff1a<\/p>\n\n\n\n

\u51c6\u5907\u5de5\u4f5c<\/h2>\n\n\n\n

\u5efa\u7acb4\u5f20\u8868\uff0c\u73ed\u4e3b\u4efb\u8868\u3001\u5b66\u751f\u8868\u3001\u8bfe\u7a0b\u8868\u3001\u9009\u8bfe\u60c5\u51b5\u8868\u3002\u73ed\u4e3b\u4efb\u548c\u5b66\u751f\u5bf9\u5e94\u7684\u662f1-N\u3001\u5b66\u751f\u548c\u8bfe\u7a0b\u5bf9\u5e94\u7684\u662fN-N\uff1a<\/p>\n\n\n\n

\"\"\/<\/div><\/figure>\n\n\n\n

\u5176\u6b21\uff0c\u521b\u5efa\u5bf9\u5e94\u76843\u4e2a\u5b9e\u4f53\u7c7b\uff1a<\/p>\n\n\n\n

public class Course {
    private Integer id;
    private String name; 
    private List<Student> students;\/\/\u591a\u8868\u67e5\u8be2 \u591a\u5bf9\u591a
    \/\/get...set...
}
\u200b
public class Student {
    private Integer id;
    private Integer tid;
    private String name;
    private Teacher teacher; \/\/\u591a\u8868\u67e5\u8be2 \u591a\u5bf9\u4e00
}
\u200b
public class Teacher {
    private Integer id;
    private String name;
    private List<Student> students; \/\/\u591a\u8868\u67e5\u8be2 \u4e00\u5bf9\u591a
}<\/pre>\n\n\n\n
1-N<\/h2>\n\n\n\n
\u4e24\u6b65\u67e5\u8be2<\/h3>\n\n\n\n
\u4e24\u6b65\u67e5\u8be2\u6bd4\u8f83\u597d\u7406\u89e3\uff0c\u5c31\u662f\u5bf9\u6301\u6709\u5f15\u7528\u5bf9\u8c61\u7684\u5bf9\u8c61\u6267\u884c\u4e24\u6b21select\u8bed\u53e5\uff0c\u628a\u5c5e\u6027\u7684\u5bf9\u8c61\u4e5f\u67e5\u51fa\u6765\u3002<\/p>\n\n\n\n
\u4ee5\u4e0b\u662f\u67e5\u8be2\u201c1-N\u201d\u7684\u4e00\u65b9\uff0c\u4e5f\u5c31\u662f\u67e5\u8be2\u8001\u5e08\u65b9\uff0c\u628a\u5e26\u7684\u5b69\u5b50\u90fd\u67e5\u8be2\u51fa\u6765\uff1a<\/p>\n\n\n\n
public List<Teacher> selectAllFromTeacher();<\/pre>\n\n\n\n
<resultMap id=\"myMap\" type=\"com.vo.Teacher\">
<!--    \u8fdb\u884c\u6570\u636e\u5e93\u5b57\u6bb5\u4e0eJavaBean\u5b57\u6bb5\u7684\u6620\u5c04-->
    <id column=\"id\" property=\"id\"><\/id>
    <result column=\"name\" property=\"name\"><\/result>
    <collection property=\"students\" select=\"com.mapper.IStudent.selectAllByTid\" column=\"id\"><\/collection>
<\/resultMap>
\u200b
<select id=\"selectAllFromTeacher\" resultMap=\"myMap\">
    select * from teacher
<\/select>
    
<select id=\"selectAllByTid\" parameterType=\"int\" resultType=\"com.vo.Student\">
        select * from student where tid = #{id}
<\/select>
\u200b<\/pre>\n\n\n\n
\u53ef\u4ee5\u770b\u5230select\u8bed\u53e5\u91cc\u6ca1\u6709\u4f7f\u7528resultType\uff0c\u800c\u662f\u7528\u4e86resultMap\u3002\u56e0\u4e3aTeacher\u91cc\u6709\u4e00\u4e2a\u5c5e\u6027\u662fstudent\u96c6\u5408\uff0c\u6240\u4ee5\u53ef\u4ee5\u4f7f\u7528resultMap\uff08\u7ed3\u679c\u6620\u5c04\uff09\u53bb\u628a\u5173\u8054\u7684student\u90fd\u6620\u5c04\u51fa\u6765\u3002<\/p>\n\n\n\n
resultType\u7528\u5230\u7684\u5b50\u5143\u7d20\u6709\uff1aid\uff08\u6807\u8bb0\u51fa\u4f5c\u4e3a ID \u7684\u7ed3\u679c\u53ef\u4ee5\u5e2e\u52a9\u63d0\u9ad8\u6574\u4f53\u6027\u80fd\uff09\u3001result\uff08\u6ce8\u5165\u5230\u5b57\u6bb5\u6216 JavaBean \u5c5e\u6027\u7684\u666e\u901a\u7ed3\u679c\uff09\u3001collection\uff08\u5d4c\u5957\u7ed3\u679c\u6620\u5c04\uff09\uff0c\u4ee5\u4e0b\u662f\u6211\u5b66\u4e60\u8fc7\u7a0b\u601d\u8003\u4e86\u6bd4\u8f83\u4e45\u7684\u70b9\uff1a<\/p>\n\n\n\n