{"id":11641,"date":"2023-08-08T20:37:46","date_gmt":"2023-08-08T12:37:46","guid":{"rendered":"http:\/\/92it.top\/?p=11641"},"modified":"2023-08-08T21:23:01","modified_gmt":"2023-08-08T13:23:01","slug":"mybatis%e7%9a%84association%e4%bb%a5%e5%8f%8acollection%e7%9a%84%e7%94%a8%e6%b3%95","status":"publish","type":"post","link":"https:\/\/92it.top\/?p=11641","title":{"rendered":"mybatis\u7684association\u4ee5\u53cacollection\u7684\u7528\u6cd5"},"content":{"rendered":"\n<p>\u5728\u9879\u76ee\u4e2d\uff0c\u67d0\u4e9b\u5b9e\u4f53\u7c7b\u4e4b\u95f4\u80af\u5b9a\u6709\u5173\u952e\u5173\u7cfb\uff0c\u6bd4\u5982\u4e00\u5bf9\u4e00\uff0c\u4e00\u5bf9\u591a\u7b49\u3002mybatis \u4e2d\u5c31\u7528<code>association<\/code>\u548c<code>collection<\/code>\u3002<\/p>\n\n\n\n<ul><li><a><\/a><a><\/a>association: \u4e00\u5bf9\u4e00\u5173\u8054(has one)<\/li><li><a><\/a><a><\/a>collection:\u4e00\u5bf9\u591a\u5173\u8054(has many)<\/li><\/ul>\n\n\n\n<p>\u6ce8\u610f\uff0c\u53ea\u6709\u5728\u505aselect\u67e5\u8be2\u65f6\u624d\u4f1a\u7528\u5230\u8fd9\u4e24\u4e2a\u6807\u7b7e\uff0c\u90fd\u6709\u4e09\u79cd\u7528\u6cd5\uff0c\u4e14\u7528\u6cd5\u7c7b\u4f3c\u3002<\/p>\n\n\n\n<p><strong>\u4e00\u3001association\u7684\u4e09\u79cd\u7528\u6cd5:<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p>Mybatis\u7684association\u6807\u7b7e\u7b80\u4ecb:<\/p>\n\n\n\n<ul><li>mybatis\u8fdb\u884c\u591a\u8868\u67e5\u8be2\u65f6\u4f1a\u7528\u4e0aassociation\u6807\u7b7e\uff0c\u5b83\u7684\u5c5e\u6027\u5305\u62ecproperty\uff0ccolumn\uff0cjavaType\u7b49\uff0c\u5b83\u7684\u4f5c\u7528\u662f\u8ba9\u5b9e\u4f53\u7c7b\u5bf9\u8c61\u4e0e\u6570\u636e\u5e93\u8868\u7684\u5217\u76f8\u4e92\u5bf9\u5e94\uff0c\u4ee5\u4fbf\u8ba9mybatis\u53ef\u4ee5\u8fdb\u884c\u591a\u8868\u67e5\u8be2\u3002<\/li><\/ul>\n\n\n\n<p>Mybatis\u7684association\u6807\u7b7e\u7528\u6cd5:\u00a0<\/p>\n\n\n\n<p>\u7b2c\u4e00\u79cd\u65b9\u5f0f\uff1a\uff08\u5d4c\u5957\u7ed3\u679c\u65b9\u5f0f\uff09<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    &lt;!-- \u5b9a\u4e49\u5c01\u88c5account\u548cuser\u7684resultMap -->\n    &lt;resultMap id=\"\u6807\u7b7e\u7684id\u65e2\u540d\u5b57,\u53ef\u968f\u610f\" type=\"\u67e5\u8be2\u7684\u4e3b\u8868\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u8def\u5f84(\u5982:cn.hdc.User)\">\n        &lt;id property=\"\u5b9e\u4f53\u7c7b\u4e2d\u8868\u793a\u4e3b\u952e\u7684\u540d\u79f0\" column=\"\u6570\u636e\u5e93\u8868\u4e3b\u952e\u540d\u79f0\">&lt;\/id>\n        &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\">&lt;\/result>\n        &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\">&lt;\/result>\n        &lt;!-- \u4e00\u5bf9\u4e00\u7684\u5173\u7cfb\u6620\u5c04\uff0c\u914d\u7f6e\u5c01\u88c5user\u7684\u5185\u5bb9 -->\n        &lt;association property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\uff08\u53e6\u4e00\u5f20\u8868\u7684\u5bf9\u8c61\uff09\" \n                     javaType=\"\u53e6\u4e00\u5f20\u8868\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u8def\u5f84\">\n            &lt;!-- \u8bf4\u660e\u5c01\u88c5\u7684\u5b9e\u4f53\u7c7b\u5bf9\u8c61 -->\n            &lt;id property=\"\u4e3b\u952e\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u4e3b\u952e\u540d\u79f0\">&lt;\/id>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n            &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\"\/>\n        &lt;\/association>\n    &lt;\/resultMap><\/pre>\n\n\n\n<p>\u7b2c\u4e8c\u79cd:(\u5d4c\u5957\u67e5\u8be2\u65b9\u5f0f)<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    &lt;!-- \u5b9a\u4e49\u5c01\u88c5account\u548cuser\u7684resultMap -->\n    &lt;resultMap id=\"\u6807\u7b7e\u7684id\u65e2\u540d\u5b57,\u53ef\u968f\u610f\" type=\"\u67e5\u8be2\u7684\u4e3b\u8868\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u540d\u79f0\u6216\u8005\u5b9e\u4f53\u7c7b\u8def\u5f84(\u5982:cn.hdc.User)\">\n        &lt;id property=\"\u5b9e\u4f53\u7c7b\u4e2d\u8868\u793a\u4e3b\u952e\u7684\u540d\u79f0\" column=\"\u6570\u636e\u5e93\u8868\u4e3b\u952e\u540d\u79f0\">&lt;\/id>\n        &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\">&lt;\/result>\n        &lt;result property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\" column=\"\u6570\u636e\u5e93\u8868\u5217\u540d\">&lt;\/result>\n        \n        &lt;!-- \u4e00\u5bf9\u4e00\u7684\u5173\u7cfb\u6620\u5c04\uff0c\u914d\u7f6e\u5c01\u88c5user\u7684\u5185\u5bb9 -->   \n        &lt;association \/\/\u8fd9\u4e2a\u5bf9\u8c61\u6765\u6e90\u4e8e\u4e0b\u8fb9select\u67e5\u5230\u7684\u7ed3\u679c\n                     property=\"\u5b9e\u4f53\u7c7b\u5c5e\u6027\uff08\u53e6\u4e00\u5f20\u8868\u7684\u5bf9\u8c61\uff09\" \n                     \/\/\u5982\u679c\u7b2c\u4e00\u5f20\u8868\u6709\u5916\u952e\uff0ccolumn=\"\u5916\u952e\u5217\u540d\"\u3002\n                     \/\/\u5982\u679c\u7b2c\u4e00\u5f20\u8868\u6ca1\u6709\u5916\u952e\uff0ccolumn=\"javaType\u5bf9\u5e94\u8868\u4e2d\u7684\u4e3b\u952e\u540d\"\n                     column=\"\u8fd9\u91cc\u662f\u6570\u636e\u5e93\u8868\u7684\u67d0\u4e00\u4e2a\u5217\u7684\u503c\uff0c\u4f5c\u4e3a\u4e0b\u8fb9select\u7684\u53c2\u6570\" \n                     javaType=\"\u53e6\u4e00\u5f20\u8868\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u8def\u5f84\"\n                     select=\"cn.hdc.mapper.findCodeById\">\n \n    &lt;\/resultMap><\/pre>\n\n\n\n<p>\u4f7f\u7528Mybatis\u7684association\u6807\u7b7e\u7684\u6ce8\u610f\u4e8b\u9879:<\/p>\n\n\n\n<ul><li>association\u6807\u7b7e\u662f\u653e\u5728resultMap\u6807\u7b7e\u4f53\u5185\u90e8\u7684\uff0c\u5728select\u6807\u7b7e\u7684resultMap\u5c5e\u6027\u4e2d\u914d\u7f6eresultMap\u6807\u7b7e\u7684id\u540dmybatis\u65b9\u53ef\u8bc6\u522b\u3002\uff08\u6ce8\u610fresultMap\u6807\u7b7e\u548cresultMap\u5c5e\u6027\u662f\u4e0d\u540c\u7684\uff0cresultMap\u6807\u7b7e\u662f\u4e00\u4e2a\u6807\u7b7e\u4f53\u53ef\u4ee5\u914d\u7f6eid\u5c5e\u6027\u548ctype\u5c5e\u6027\uff0c\u800cresultMap\u5c5e\u6027\u662f\u653e\u5728\u6807\u7b7e\u4f53\u5185\u90e8\u7684\uff0c\u9700\u8981\u914d\u7f6eresultMap\u6807\u7b7e\u7684id\u5c5e\u6027\uff09<\/li><li>association\u6807\u7b7e\u7684javaType\u5c5e\u6027\u4e0d\u80fd\u9057\u6f0f\uff0c\u4e0d\u7136mybatis\u5c06\u4e0d\u77e5\u9053\u662f\u54ea\u4e2a\u5b9e\u4f53\u7c7b\u7684\u5c5e\u6027\u548c\u5b9e\u4f53\u7c7b\u8868\u76f8\u4e92\u5bf9\u5e94\u3002<\/li><\/ul>\n\n\n\n<p>\u63a5\u4e0b\u6765\u770b\u53e6\u4e00\u4e2a\u4f8b\u5b50\uff0c\u5148\u770b\u5982\u4e0b\u4ee3\u7801(\u7701\u7565set\u3001get\u65b9\u6cd5):<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public class User {\n    private Integer userId;\n    private String userName;\n    private Integer age;\n    private Card card;\/\/\u4e00\u4e2a\u4eba\u4e00\u5f20\u8eab\u4efd\u8bc1,1\u5bf91\n}\n\npublic class Card {\n    private Integer cardId;\n    private String cardNum;\/\/\u8eab\u4efd\u8bc1\u53f7\n    private String address;\/\/\u5730\u5740\n}\n\npublic interface UserDao {\n    \/**\n     * \u901a\u8fc7userId\u67e5\u8be2user\u4fe1\u606f\n     * @param userId\n     * @return\n     *\/\n    User queryById(int userId);\n\n}\n<\/pre>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\"> &lt;select id=\"queryById\" parameterType=\"int\" resultMap=\"userMap\">\n        SELECT u.user_name,u.age,c.card_id,c.card_num,c.address\n        FROM tb_user u,tb_card c\n        WHERE u.card_id=c.card_id\n        ANDu.user_id=#{userId}\n    &lt;\/select>\n<\/pre>\n\n\n\n<p>\u4ee5\u4e0a\u662f\u5b9e\u4f53\u7c7b\u3001dao\u5c42\u7684\u8bbe\u8ba1\u4ee5\u53ca\u5728UserDao.xml\u4e2dqueryById\u65b9\u6cd5\u7684sql\u8bed\u53e5\u7684\u7f16\u5199\uff0c\u56e0\u4e3a\u4e0d\u8bba\u7528association\u7684\u54ea\u79cd\u65b9\u5f0f\uff0csql\u8bed\u53e5\u90fd\u662f\u4e00\u6837\u7684\u5199\uff0c\u4e0d\u540c\u7684\u53ea\u662fuserMap\u7684\u5199\u6cd5\uff0c\u6240\u4ee5\u8fd9\u91cc\u5148\u7ed9\u51fa\u8fd9\u6bb5\u4ee3\u7801\u3002User\u8be2Card\u662f\u4e00\u5bf9\u4e00\u5173\u7cfb\uff0c\u5728\u6570\u636e\u5e93\u4e2d\uff0ctb_user\u8868\u901a\u8fc7\u5916\u952ecard_id\u5173\u8054tb_card\u8868\u3002\u4e0b\u9762\u5206\u522b\u7528association\u7684\u4e09\u79cd\u7528\u6cd5\u6765\u5b9e\u73b0queryById\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p><strong>1\u3001\u7b2c\u4e00\u79cd\u7528\u6cd5:association\u4e2d\u4f7f\u7528select<\/strong><\/p>\n\n\n\n<p>\u8fd9\u79cd\u65b9\u6cd5\u9700\u8981\u518d\u5b9a\u4e49CardDao.java\uff0c\u5982\u4e0b:<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public interface CardDao {\n    Card queryCardById(int cardId);\n}\n<\/pre>\n\n\n\n<p><br>\u5728CardDao.xml\u4e2d\u5b9e\u73b0\u8be5\u65b9\u6cd5:<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\"> &lt;select id=\"queryCardById\" parameterType=\"int\" resultType=\"Card\">\n        SELECT *\n        FROM tb_card\n        WHERE card_id=#{cardId}\n &lt;\/select>\n<\/pre>\n\n\n\n<p>\u7136\u540e\u518d\u770bUserDao.xml\u4e2d\u662f\u5982\u4f55\u5f15\u7528\u8fd9\u4e2a\u65b9\u6cd5\u7684:<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"User\" id=\"userMap\">\n    &lt;result property=\"userName\" column=\"user_name\"\/>\n\n    &lt;result property=\"age\" column=\"age\"\/>\n\n   &lt;association property=\"card\" column=\"card_id\" select=\"com.zhu.ssm.dao.CardDao.queryCardById\">\n   &lt;\/association>\n&lt;\/resultMap>\n<\/pre>\n\n\n\n<p>\u5728\u8fd9\u91cc\u76f4\u63a5\u901a\u8fc7select\u5f15\u7528CardDao\u7684queryById\u65b9\u6cd5\u3002\u4e2a\u4eba\u611f\u89c9\u8fd9\u79cd\u65b9\u6cd5\u6bd4\u8f83\u9ebb\u70e6\uff0c\u56e0\u4e3a\u8fd8\u8981\u5728CardDao\u91cc\u5b9a\u4e49queryCardById\u65b9\u6cd5\u5e76\u4e14\u5b9e\u73b0\u518d\u5f15\u7528\u624d\u6709\u7528\uff0c\u4e0d\u8fc7\u8fd9\u79cd\u65b9\u6cd5\u601d\u8def\u6e05\u6670\uff0c\u6613\u4e8e\u7406\u89e3\u3002<\/p>\n\n\n\n<p><strong>2\u3001\u7b2c\u4e8c\u79cd\u65b9\u6cd5\uff0c\u5d4c\u5957resultMap<\/strong><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"Card\" id=\"cardMap\">\n      &lt;id property=\"cardId\"  column=\"card_id\"\/>\n\n      &lt;result property=\"cardNum\"  column=\"card_num\"\/>\n\n      &lt;result property=\"address\"  column=\"address\"\/>\n&lt;\/resultMap>\n\n\n&lt;resultMap type=\"User\" id=\"userMap\">\n     &lt;result property=\"userName\" column=\"user_name\"\/>\n\n     &lt;result property=\"age\" column=\"age\"\/>\n\n     &lt;association property=\"card\" resultMap=\"cardMap\">\n     &lt;\/association>\n&lt;\/resultMap>\n<\/pre>\n\n\n\n<p>\u7b2c\u4e8c\u79cd\u65b9\u6cd5\u5c31\u662f\u5728UserDao.xml\u4e2d\u5148\u5b9a\u4e49\u4e00\u4e2aCard\u7684resultMap\uff0c\u7136\u540e\u5728User\u7684resultMap\u7684association\u6807\u7b7e\u4e2d\u901a\u8fc7resultMap=&#8221;cardMap&#8221;\u5f15\u7528\u3002\u8fd9\u79cd\u65b9\u6cd5\u76f8\u6bd4\u4e8e\u7b2c\u4e00\u79cd\u65b9\u6cd5\u8f83\u4e3a\u7b80\u5355\u3002<\/p>\n\n\n\n<p><strong>3\u3001\u7b2c\u4e09\u79cd\u65b9\u6cd5:\u5d4c\u5957resultMap\u7b80\u5316\u7248<\/strong><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"User\" id=\"userMap\">\n   &lt;result property=\"userName\" column=\"user_name\"\/>\n\n   &lt;result property=\"age\" column=\"age\"\/>\n\n   &lt;association property=\"card\" column=\"card_id\" javaType=\"Card\">\n      &lt;id property=\"cardId\" column=\"card_id\"\/>\n      &lt;result property=\"cardNum\" column=\"card_num\"\/>\n      &lt;result property=\"address\" column=\"address\"\/>\n    &lt;\/association>\n&lt;\/resultMap> \n<\/pre>\n\n\n\n<p>\u8fd9\u79cd\u65b9\u6cd5\u5c31\u628aCard\u7684resultMap\u5b9a\u4e49\u5728\u4e86association \u6807\u7b7e\u91cc\u9762\uff0c\u901a\u8fc7javaType\u6765\u6307\u5b9a\u662f\u54ea\u4e2a\u7c7b\u7684resultMap\uff0c\u4e2a\u4eba\u8ba4\u4e3a\u8fd9\u79cd\u65b9\u6cd5\u6700\u7b80\u5355\uff0c\u7f3a\u70b9\u5c31\u662fcardMap\u4e0d\u80fd\u590d\u7528\u3002\u5177\u4f53\u7528\u54ea\u79cd\u65b9\u6cd5\uff0c\u89c6\u60c5\u51b5\u800c\u5b9a\u3002<\/p>\n\n\n\n<p><strong>\u4e8c\u3001collection\u7684\u4e09\u79cd\u7528\u6cd5:<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p>\u4e00\u4e2a\u571f\u8c6a\u6709\u591a\u4e2a\u624b\u673a\uff0c\u770b\u5982\u4e0b\u4ee3\u7801:<br>User\u5b9e\u4f53\u7c7b<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public class User{\n  private Integer userId;\n    private String userName;\n    private Integer age;\n    private List&lt;MobilePhone> mobilePhone;\/\/\u571f\u8c6a,\u591a\u4e2a\u624b\u673a,1\u5bf9\u591a\n}\n<\/pre>\n\n\n\n<p>\u624b\u673a\u7c7b<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public class MobilePhone {\n    private Integer mobilePhoneId;\n    private String brand;\/\/\u54c1\u724c\n    private double price;\/\/\u4ef7\u683c\n    private User user;\/\/\u4e3b\u4eba\n}\n<\/pre>\n\n\n\n<p>dao\u5c42<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public interface UserDao {\n    \/**\n     * \u901a\u8fc7userId\u67e5\u8be2user\u4fe1\u606f\n     * @param userId\n     * @return\n     *\/\n    User queryById(int userId);\n}\n<\/pre>\n\n\n\n<p>UserDao.xml\u4e2d\u7684select\u67e5\u8be2\u8bed\u53e5<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;select id=\"queryById\" parameterType=\"int\" resultMap=\"userMap\">\n        SELECT u.user_name,u.age, m.brand,m.price\n        FROM tb_user u,tb_mobile_phone m\n        WHERE m.user_id=u.user_id\n        AND\n        u.user_id=#{userId}\n&lt;\/select>\n<\/pre>\n\n\n\n<p>\u6570\u636e\u5e93\u4e2d\uff0ctb_mobile_phone\u4e2duser_id\u4f5c\u4e3a\u5916\u952e\u3002\u90a3\u4e48\u4e0b\u9762\u6765\u770bresultMap\u5982\u4f55\u5b9a\u4e49:<\/p>\n\n\n\n<p><strong>1\u3001\u7b2c\u4e00\u79cd\u65b9\u6cd5:\u7528select\uff0c\u8ddfassociation \u4e2d\u4f7f\u7528select\u7c7b\u4f3c:<\/strong><\/p>\n\n\n\n<p>\u5148\u5b9a\u4e49 MobilePhoneDao.java<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">public interface MobilePhoneDao {\n    List&lt;MobilePhone> queryMbByUserId(int userId);\n}<\/pre>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"MobilePhone\" id=\"mobilePhoneMap\">\n     &lt;id property=\"mobilePhoneId\" column=\"user_id\"\/>\n     &lt;result property=\"brand\" column=\"brand\"\/>\n     &lt;result property=\"price\" column=\"price\"\/>\n     &lt;association property=\"user\" column=\"user_id\" select= \"com.zhu.ssm.dao.UserDao.queryById\">\n     &lt;\/association>\n&lt;\/resultMap>\n<\/pre>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;select id=\"queryMbByUserId\" parameterType=\"int\" resultMap=\"mobilePhoneMap\">\n        SELECT brand,price\n        FROM tb_mobile_phone\n        WHERE user_id=#{userId}\n    &lt;\/select>\n<\/pre>\n\n\n\n<p>\u505a\u597d\u4ee5\u4e0a\u51c6\u5907\u5de5\u4f5c\uff0c\u90a3\u5c31\u53ef\u4ee5\u5728UserDao.xml\u4e2d\u5f15\u7528\u4e86<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"User\" id=\"userMap\">\n        &lt;id property=\"userId\" column=\"user_id\"\/>\n        &lt;result property=\"userName\"  column=\"user_name\"\/>\n        &lt;result property=\"age\" column=\"age\"\/>\n        &lt;collection property=\"mobilePhone\" column=\"user_id\" select=\"com.zhu.ssm.dao.MobilePhoneDao.queryMbByUserId\">\n        &lt;\/collection>\n&lt;\/resultMap> \n<\/pre>\n\n\n\n<p>\u8fd9\u79cd\u65b9\u6cd5\u548cassociation\u7684\u7b2c\u4e00\u79cd\u7528\u6cd5\u51e0\u4e4e\u662f\u4e00\u6837\u7684\u4e0d\u540c\u4e4b\u5904\u5c31\u662fmobilePhMap\u4e2d\u7528\u5230\u4e86association \uff0cqueryMbByUserId\u4e2d\u8981\u4f7f\u7528mobilePhoneMap\uff0c\u800c\u4e0d\u80fd\u76f4\u63a5\u4f7f\u7528resultType\u3002<\/p>\n\n\n\n<p><strong>2\u3001\u7b2c\u4e8c\u79cd\u65b9\u6cd5:\u5d4c\u5957resultMap<\/strong><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    &lt;resultMap type=\"MobilePhone\" id=\"mobilephoneMap\">\n         &lt;id column=\"mobile_phone_id\" property=\"mobilePhoneId\"\/>\n         &lt;result column=\"brand\" property=\"brand\" \/>\n         &lt;result column=\"price\" property=\"price\" \/>\n    &lt;\/resultMap>\n\n    &lt;resultMap type=\"User\" id=\"userMap\">\n        &lt;result property=\"userName\" column=\"user_name\"\/>\n        &lt;result property=\"age\" column=\"age\"\/>\n        &lt;collection property=\"mobilePhone\" resultMap=\"mobilephoneMap\" >\n        &lt;\/collection>\n    &lt;\/resultMap> \n<\/pre>\n\n\n\n<p>\u5b9a\u4e49\u597d\u8fd9\u4e24\u4e2aresultMap\uff0c\u518d\u5f15\u7528UserMap\u5c31\u884c\u4e86\u3002<\/p>\n\n\n\n<p><strong>3\u3001\u7b2c\u4e09\u79cd\u65b9\u6cd5:\u5d4c\u5957resultMap\u7b80\u5316\u7248<\/strong><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;resultMap type=\"User\" id=\"userMap\">\n     &lt;result property=\"userName\" column=\"user_name\"\/>\n     &lt;result property=\"age\" column=\"age\"\/>\n     &lt;collection property=\"mobilePhone\" column=\"user_id\" ofType=\"MobilePhone\">\n      &lt;id column=\"mobile_phone_id\" property=\"mobilePhoneId\" \/>\n      &lt;result column=\"brand\" property=\"brand\" \/>\n      &lt;result column=\"price\" property=\"price\" \/>\n     &lt;\/collection>\n&lt;\/resultMap>\n<\/pre>\n\n\n\n<p>\u8fd9\u79cd\u65b9\u6cd5\u9700\u8981\u6ce8\u610f\uff0c\u4e00\u5b9a\u8981\u6709ofType\uff0ccollection \u88c5\u7684\u5143\u7d20\u7c7b\u578b\u662f\u5565ofType\u7684\u503c\u5c31\u662f\u5565\uff0c\u8fd9\u4e2a\u4e00\u5b9a\u4e0d\u80fd\u5c11\u3002<br>\u6ce8\u610f:<br>\u6240\u6709resultMap\u4e2d\u7684type\u3001select \u6807\u7b7e\u4e2d\u7684resultType\u4ee5\u53caassociation\u4e2d\u7684javaType\uff0ccollection\u4e2d\u7684ofType\uff0c\u8fd9\u91cc\u53ea\u5199\u4e86\u7c7b\u540d\uff0c\u662f\u56e0\u4e3a\u5728mybatis-config.xml\u4e2d\u914d\u7f6e\u4e86typeAliases\uff0c\u5426\u5219\u5c31\u8981\u5199\u8be5\u7c7b\u7684\u5168\u7c7b\u540d\u3002\u914d\u7f6e\u5982\u4e0b:<br><\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">&lt;typeAliases>\n&lt;packagename=\"com.zhu.smm.entity\"\/>\n&lt;\/typeAliases><\/pre>\n\n\n\n<p><strong>\u603b\u7ed3:<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><br>1\u3001association\u8868\u793a\u7684\u662fhas one\u7684\u5173\u7cfb\uff0c\u4e00\u5bf9\u4e00\u65f6\u4f7f\u7528\u3002user has one card\uff0c\u6240\u4ee5\u5728user\u7684resultMap\u4e2d\u63a5\u6536card\u65f6\u5e94\u8be5\u7528association;<br>2\u3001collection\u8868\u793a\u7684\u662fhas many\u7684\u5173\u7cfb\uff0c\u4e00\u5bf9\u591a\u65f6\u4f7f\u7528\u3002user has many mobilePhone\uff0c\u6240\u4ee5\u5728user\u7684resultMap\u4e2d\u63a5\u6536mobilePhone\u65f6\u5e94\u8be5\u7528collection \u3002<br>3\u3001\u90fd\u6709\u4e09\u79cd\u7528\u6cd5\uff0c\u4e14\u975e\u5e38\u7c7b\u4f3c\uff0cresultMap\u8981\u590d\u7528\u5efa\u8bae\u7b2c\u4e8c\u79cd\u65b9\u6cd5\uff0c\u4e0d\u9700\u8981\u590d\u7528\u5efa\u8bae\u7b2c\u4e09\u79cd\u65b9\u6cd5\u3002<br>4\u3001\u7279\u522b\u6ce8\u610f\u8868\u4e2d\u4e3b\u952e\u5b57\u6bb5\u8981\u6709\u6240\u533a\u5206\uff0c\u4e0d\u80fd\u90fd\u5199\u6210id\uff0c\u8981\u5199\u6210user_id\u3001card_id\uff0c\u53cd\u6b63\u8981\u6709\u6240\u533a\u5206\uff0c\u4e0d\u7136\u67e5\u8be2\u7684\u65f6\u5019\u4f1a\u67e5\u4e0d\u5230\u5b8c\u6574\u7684\u6570\u636e\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-1024x946.png\" alt=\"\" class=\"wp-image-11645\" width=\"453\" height=\"418\" srcset=\"https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-1024x946.png 1024w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-300x277.png 300w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-768x710.png 768w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-1536x1419.png 1536w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-830x767.png 830w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-230x213.png 230w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-350x323.png 350w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247-480x444.png 480w, https:\/\/92it.top\/wp-content\/uploads\/2023\/08\/\u56fe\u7247.png 1632w\" sizes=\"(max-width: 453px) 100vw, 453px\" \/><\/figure><\/div>\n\n\n\n<p><br><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u9879\u76ee\u4e2d\uff0c\u67d0\u4e9b\u5b9e\u4f53\u7c7b\u4e4b\u95f4\u80af\u5b9a\u6709\u5173\u952e\u5173\u7cfb\uff0c\u6bd4\u5982\u4e00\u5bf9\u4e00\uff0c\u4e00\u5bf9\u591a\u7b49\u3002mybatis \u4e2d\u5c31\u7528association\u548cc [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"_links":{"self":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/11641"}],"collection":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11641"}],"version-history":[{"count":5,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/11641\/revisions"}],"predecessor-version":[{"id":11648,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/11641\/revisions\/11648"}],"wp:attachment":[{"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11641"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11641"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11641"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}