\u521a\u63a5\u89e6 MyBatis \u65f6，\u6211\u4e00\u76f4\u89c9\u5f97 Mapper \u63a5\u53e3\u6709\u70b9\u201c\u795e\u5947\u201d：\u63a5\u53e3\u660e\u660e\u6ca1\u6709\u5b9e\u73b0\u7c7b，\u6ce8\u5165\u540e\u5374\u80fd\u76f4\u63a5\u8c03\u7528；XML \u91cc\u5199\u4e00\u6bb5 SQL，\u8fd4\u56de\u503c\u53c8\u80fd\u81ea\u52a8\u53d8\u6210 Java \u5bf9\u8c61\u3002<\/p>\n
\u540e\u9762\u518d\u56de\u5934\u770b，\u4f1a\u53d1\u73b0 MyBatis \u5e76\u6ca1\u6709\u51ed\u7a7a\u505a\u4ec0\u4e48\u3002\u5b83\u7684\u6838\u5fc3\u903b\u8f91\u5f88\u6e05\u695a：\u542f\u52a8\u65f6\u89e3\u6790 SQL \u548c\u6620\u5c04\u89c4\u5219，\u8fd0\u884c\u65f6\u4e3a Mapper \u63a5\u53e3\u521b\u5efa\u4ee3\u7406\u5bf9\u8c61，\u518d\u7531\u4ee3\u7406\u5bf9\u8c61\u627e\u5230\u5bf9\u5e94 SQL \u5e76\u4ea4\u7ed9\u6267\u884c\u5668\u5904\u7406\u3002<\/p>\n
\u672c\u6587\u4ece\u5b9e\u9645\u5f00\u53d1\u4e2d\u7ecf\u5e38\u88ab\u95ee\u5230\u7684\u4e94\u4e2a\u95ee\u9898\u5165\u624b，\u628a MyBatis \u4e0e JPA\u3001\u7f13\u5b58\u3001\u7ed3\u679c\u6620\u5c04\u548c Mapper \u4ee3\u7406\u4e32\u8d77\u6765\u8bb2\u6e05\u695a\u3002<\/p>\n
\u5148\u7ea0\u6b63\u4e00\u4e2a\u5e38\u89c1\u8bf4\u6cd5：MyBatis \u4e0e JPA \u5e76\u4e0d\u662f\u5b8c\u5168\u5bf9\u7b49\u7684\u4e24\u4e2a\u6846\u67b6\u3002<\/p>\n
MyBatis \u662f\u4e00\u4e2a SQL \u6620\u5c04\u6846\u67b6，\u5f00\u53d1\u8005\u81ea\u5df1\u7f16\u5199 SQL，\u5b83\u8d1f\u8d23\u53c2\u6570\u7ed1\u5b9a\u3001SQL \u6267\u884c\u548c\u7ed3\u679c\u6620\u5c04\u3002JPA \u5219\u662f Java \u6301\u4e45\u5316\u89c4\u8303，Hibernate \u662f\u5e38\u89c1\u5b9e\u73b0，Spring Data JPA \u53c8\u5728 JPA \u4e4b\u4e0a\u5c01\u88c5\u4e86 Repository \u7b49\u80fd\u529b\u3002<\/p>\n
\u5982\u679c\u7cfb\u7edf\u4e2d\u590d\u6742\u67e5\u8be2\u591a\u3001SQL \u8c03\u4f18\u8981\u6c42\u9ad8，MyBatis \u5f80\u5f80\u66f4\u987a\u624b；\u5982\u679c\u4e1a\u52a1\u4ee5\u6807\u51c6 CRUD \u548c\u9886\u57df\u5bf9\u8c61\u5173\u7cfb\u4e3a\u4e3b，JPA \u53ef\u4ee5\u51cf\u5c11\u4e0d\u5c11\u91cd\u590d\u4ee3\u7801\u3002<\/p>\n
\u8c08\u4e8c\u7ea7\u7f13\u5b58\u524d，\u9700\u8981\u5148\u533a\u5206\u4e00\u7ea7\u7f13\u5b58\u3002<\/p>\n
\u4e00\u7ea7\u7f13\u5b58\u5c5e\u4e8e SqlSession，\u9ed8\u8ba4\u5f00\u542f\u3002\u540c\u4e00\u4e2a SqlSession \u4e2d\u6267\u884c\u76f8\u540c\u67e5\u8be2，\u53ef\u4ee5\u76f4\u63a5\u590d\u7528\u7ed3\u679c\u3002<\/p>\n<\/li>\n
\u4e8c\u7ea7\u7f13\u5b58\u5c5e\u4e8e Mapper \u7684 namespace，\u53ef\u4ee5\u5728\u591a\u4e2a SqlSession \u4e4b\u95f4\u5171\u4eab\u3002<\/p>\n<\/li>\n<\/ul>\n
\u5728 Mapper XML \u4e2d\u52a0\u5165\u4e0b\u9762\u7684\u914d\u7f6e\u5373\u53ef\u5f00\u542f\u5f53\u524d\u547d\u540d\u7a7a\u95f4\u7684\u4e8c\u7ea7\u7f13\u5b58：<\/p>\n
<mapper namespace="com.example.mapper.UserMapper">
\n <cache\/>
\n<\/mapper><\/p>\n
\u4e00\u6b21\u67e5\u8be2\u53ef\u4ee5\u7b80\u5355\u7406\u89e3\u4e3a：\u5148\u68c0\u67e5\u5f53\u524d\u4f1a\u8bdd\u7684\u4e00\u7ea7\u7f13\u5b58，\u518d\u6839\u636e\u7f13\u5b58\u6267\u884c\u5668\u68c0\u67e5\u4e8c\u7ea7\u7f13\u5b58，\u672a\u547d\u4e2d\u65f6\u624d\u8bbf\u95ee\u6570\u636e\u5e93\u3002\u67e5\u8be2\u7ed3\u679c\u4e0d\u4f1a\u7acb\u523b\u8fdb\u5165\u4e8c\u7ea7\u7f13\u5b58，\u901a\u5e38\u8981\u7b49 SqlSession \u63d0\u4ea4\u6216\u5173\u95ed\u540e\u624d\u4f1a\u5199\u5165\u3002<\/p>\n
\u5047\u8bbe\u4e24\u4e2a SqlSession \u8c03\u7528\u540c\u4e00\u4e2a UserMapper \u67e5\u8be2\u7528\u6237：\u7b2c\u4e00\u4e2a\u4f1a\u8bdd\u67e5\u8be2\u6570\u636e\u5e93\u5e76\u63d0\u4ea4\u540e，\u7b2c\u4e8c\u4e2a\u4f1a\u8bdd\u518d\u6267\u884c\u76f8\u540c\u8bed\u53e5，\u5c31\u53ef\u80fd\u547d\u4e2d\u4e8c\u7ea7\u7f13\u5b58\u3002<\/p>\n
\u5f53\u540c\u4e00 namespace \u4e0b\u6267\u884c insert\u3001update \u6216 delete \u65f6，MyBatis \u9ed8\u8ba4\u4f1a\u6e05\u7a7a\u76f8\u5173\u7f13\u5b58，\u907f\u514d\u7ee7\u7eed\u8bfb\u53d6\u65e7\u6570\u636e\u3002\u67e5\u8be2\u6807\u7b7e\u8fd8\u53ef\u4ee5\u901a\u8fc7\u5c5e\u6027\u63a7\u5236\u884c\u4e3a：<\/p>\n
<select id="findById"
\n resultType="com.example.domain.User"
\n useCache="true"
\n flushCache="false">
\n select id, user_name from user where id = #{id}
\n<\/select><\/p>\n
\u4e8c\u7ea7\u7f13\u5b58\u770b\u8d77\u6765\u65b9\u4fbf，\u4f46\u5b9e\u9645\u9879\u76ee\u4e2d\u8981\u8c28\u614e\u4f7f\u7528\u3002\u5b83\u4ee5 namespace \u4e3a\u8fb9\u754c，\u5982\u679c\u4e00\u5f20\u8868\u88ab\u591a\u4e2a Mapper \u4fee\u6539，\u7f13\u5b58\u672a\u5fc5\u80fd\u88ab\u6b63\u786e\u611f\u77e5\u548c\u6e05\u7406；\u5206\u5e03\u5f0f\u90e8\u7f72\u4e0b，\u5404\u5b9e\u4f8b\u7684\u672c\u5730\u7f13\u5b58\u4e5f\u4e0d\u4e00\u81f4\u3002\u56e0\u6b64，\u5bf9\u4e00\u81f4\u6027\u8981\u6c42\u9ad8\u7684\u4e1a\u52a1，\u56e2\u961f\u5f80\u5f80\u66f4\u613f\u610f\u4f7f\u7528 Redis \u7b49\u8fb9\u754c\u66f4\u660e\u786e\u7684\u7f13\u5b58\u65b9\u6848\u3002<\/p>\n
\u4e8c\u8005\u90fd\u7528\u4e8e\u544a\u8bc9 MyBatis\u201c\u67e5\u8be2\u7ed3\u679c\u5e94\u8be5\u600e\u6837\u8f6c\u6362\u6210 Java \u5bf9\u8c61\u201d，\u533a\u522b\u5728\u4e8e\u6620\u5c04\u80fd\u529b\u3002<\/p>\n
\u5f53\u5217\u540d\u4e0e Java \u5c5e\u6027\u540d\u80fd\u591f\u76f4\u63a5\u5bf9\u5e94\u65f6，\u4f7f\u7528 resultType \u6700\u7701\u4e8b：<\/p>\n
<select id="findById" resultType="com.example.domain.User">
\n select id, user_name as userName
\n from user
\n where id = #{id}
\n<\/select><\/p>\n
\u8fd9\u91cc\u901a\u8fc7 SQL \u522b\u540d\u8ba9 user_name \u5bf9\u5e94 userName\u3002\u5982\u679c\u5f00\u542f\u4e0b\u5212\u7ebf\u8f6c\u9a7c\u5cf0\u914d\u7f6e，\u5f88\u591a\u573a\u666f\u751a\u81f3\u4e0d\u9700\u8981\u522b\u540d\u3002<\/p>\n
\u5b57\u6bb5\u540d\u5dee\u5f02\u8f83\u5927，\u6216\u8005\u5b58\u5728\u5d4c\u5957\u5bf9\u8c61\u3001\u4e00\u5bf9\u4e00\u3001\u4e00\u5bf9\u591a\u5173\u7cfb\u65f6，resultMap \u66f4\u5408\u9002：<\/p>\n
<resultMap id="userMap" type="com.example.domain.User">
\n <id property="id" column="user_id"\/>
\n <result property="userName" column="user_name"\/>
\n <collection property="roles"
\n ofType="com.example.domain.Role">
\n <id property="id" column="role_id"\/>
\n <result property="name" column="role_name"\/>
\n <\/collection>
\n<\/resultMap><\/p>\n
<select id="findWithRoles" resultMap="userMap">
\n select …
\n<\/select><\/p>\n
\u53ef\u4ee5\u628a resultType \u7406\u89e3\u4e3a\u201c\u544a\u8bc9 MyBatis \u8fd4\u56de\u4ec0\u4e48\u7c7b\u578b\u201d，\u628a resultMap \u7406\u89e3\u4e3a\u201c\u660e\u786e\u63cf\u8ff0\u6bcf\u4e2a\u5b57\u6bb5\u600e\u4e48\u88c5\u914d\u201d\u3002\u4e00\u6761 SQL \u901a\u5e38\u4e8c\u9009\u4e00，\u4e0d\u80fd\u540c\u65f6\u6307\u5b9a\u4e24\u8005\u3002<\/p>\n
\u5e38\u89c1\u7ed1\u5b9a\u65b9\u5f0f\u4e3b\u8981\u6709 XML \u548c\u6ce8\u89e3\u4e24\u79cd\u3002<\/p>\n
XML \u7684 namespace \u5fc5\u987b\u662f Mapper \u63a5\u53e3\u7684\u5168\u9650\u5b9a\u540d，SQL \u6807\u7b7e\u7684 id \u5fc5\u987b\u4e0e\u63a5\u53e3\u65b9\u6cd5\u540d\u5bf9\u5e94：<\/p>\n
public interface UserMapper {
\n User findById(Long id);
\n}<\/p>\n
<mapper namespace="com.example.mapper.UserMapper">
\n <select id="findById" resultType="com.example.domain.User">
\n select * from user where id = #{id}
\n <\/select>
\n<\/mapper><\/p>\n
MyBatis \u6700\u7ec8\u4f7f\u7528\u7684\u8bed\u53e5\u6807\u8bc6\u662f：<\/p>\n
com.example.mapper.UserMapper.findById<\/p>\n
\u7b80\u5355 SQL \u4e5f\u53ef\u4ee5\u76f4\u63a5\u5199\u5728\u63a5\u53e3\u65b9\u6cd5\u4e0a：<\/p>\n
@Mapper
\npublic interface UserMapper {
\n @Select("select * from user where id = #{id}")
\n User findById(Long id);
\n}<\/p>\n
@Mapper \u6216 @MapperScan \u7684\u4f5c\u7528\u662f\u626b\u63cf\u63a5\u53e3\u3001\u6ce8\u518c Mapper Bean；\u771f\u6b63\u5c06\u65b9\u6cd5\u4e0e SQL \u5173\u8054\u8d77\u6765\u7684，\u662f XML \u4e2d\u7684 namespace + id \u6216\u65b9\u6cd5\u4e0a\u7684 SQL \u6ce8\u89e3\u3002<\/p>\n
\u590d\u6742 SQL \u66f4\u9002\u5408 XML，\u7b80\u5355\u4e14\u7a33\u5b9a\u7684 SQL \u4f7f\u7528\u6ce8\u89e3\u4f1a\u66f4\u7d27\u51d1\u3002\u9879\u76ee\u4e2d\u53ef\u4ee5\u5171\u5b58，\u4f46\u6700\u597d\u5efa\u7acb\u7edf\u4e00\u89c4\u8303，\u907f\u514d\u540c\u4e00\u6761\u8bed\u53e5\u5728\u4e24\u5904\u7ef4\u62a4\u3002<\/p>\n
Mapper \u63a5\u53e3\u80fd\u591f\u76f4\u63a5\u8c03\u7528，\u9760\u7684\u662f\u52a8\u6001\u4ee3\u7406\u3002<\/p>\n
Spring \u542f\u52a8\u65f6，MyBatis \u626b\u63cf Mapper \u63a5\u53e3，\u901a\u8fc7 MapperFactoryBean \u5c06\u5176\u6ce8\u518c\u4e3a Bean\u3002\u771f\u6b63\u6ce8\u5165\u4e1a\u52a1\u7c7b\u7684\u4e0d\u662f\u63a5\u53e3\u5b9e\u73b0\u7c7b，\u800c\u662f\u7531 MapperProxyFactory \u521b\u5efa\u7684\u4ee3\u7406\u5bf9\u8c61\u3002<\/p>\n
\u5f53\u6211\u4eec\u8c03\u7528：<\/p>\n
userMapper.findById(1L);<\/p>\n
\u8bf7\u6c42\u4f1a\u8fdb\u5165 MapperProxy\u3002\u4ee3\u7406\u5bf9\u8c61\u6839\u636e\u201c\u63a5\u53e3\u5168\u9650\u5b9a\u540d + \u65b9\u6cd5\u540d\u201d\u627e\u5230\u5bf9\u5e94\u7684 MappedStatement，\u7136\u540e\u901a\u8fc7 SqlSession \u6267\u884c\u67e5\u8be2\u3002<\/p>\n
\u540e\u7eed\u53ef\u4ee5\u6982\u62ec\u4e3a\u4e0b\u9762\u8fd9\u6761\u94fe\u8def：<\/p>\n
Mapper \u63a5\u53e3\u65b9\u6cd5
\n \u2192 MapperProxy
\n \u2192 MapperMethod
\n \u2192 SqlSession
\n \u2192 Executor
\n \u2192 StatementHandler
\n \u2192 JDBC
\n \u2192 ResultSetHandler
\n \u2192 Java \u5bf9\u8c61<\/p>\n
\u5176\u4e2d，Executor \u8d1f\u8d23\u6267\u884c\u7b56\u7565\u548c\u7f13\u5b58，StatementHandler \u8d1f\u8d23\u521b\u5efa\u5e76\u64cd\u4f5c JDBC Statement，ParameterHandler \u8d1f\u8d23\u8bbe\u7f6e\u53c2\u6570，ResultSetHandler \u5219\u6309\u7167 resultType \u6216 resultMap \u5c06\u7ed3\u679c\u96c6\u8f6c\u6362\u6210 Java \u5bf9\u8c61\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u524d\u8a00\u521a\u63a5\u89e6 MyBatis \u65f6，\u6211\u4e00\u76f4\u89c9\u5f97 Mapper \u63a5\u53e3\u6709\u70b9\u201c\u795e\u5947\u201d：\u63a5\u53e3\u660e\u660e\u6ca1\u6709\u5b9e\u73b0\u7c7b，\u6ce8\u5165\u540e\u5374\u80fd\u76f4\u63a5\u8c03\u7528；XML \u91cc\u5199\u4e00\u6bb5 SQL，\u8fd4\u56de\u503c\u53c8\u80fd\u81ea\u52a8\u53d8\u6210 Java \u5bf9\u8c61\u3002\u540e\u9762\u518d\u56de\u5934\u770b，\u4f1a\u53d1\u73b0 MyBatis \u5e76\u6ca1\u6709\u51ed\u7a7a\u505a\u4ec0\u4e48\u3002\u5b83\u7684\u6838\u5fc3\u903b\u8f91\u5f88\u6e05\u695a：\u542f\u52a8\u65f6\u89e3\u6790 SQL \u548c\u6620\u5c04\u89c4\u5219，\u8fd0\u884c\u65f6\u4e3a Mapper \u63a5\u53e3\u521b\u5efa\u4ee3\u7406\u5bf9\u8c61，\u518d\u7531\u4ee3\u7406\u5bf9\u8c61\u627e\u5230\u5bf9\u5e94 SQ<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10187,99,1769,223],"topic":[],"class_list":["post-97648","post","type-post","status-publish","format-standard","hentry","category-server","tag-codingplan","tag-java","tag-mybatis","tag-tomcat"],"yoast_head":"\n