{"id":10006600,"date":"2022-09-26T16:34:17","date_gmt":"2022-09-26T08:34:17","guid":{"rendered":"https:\/\/ityet.com\/?p=10006600"},"modified":"2022-09-26T16:34:17","modified_gmt":"2022-09-26T08:34:17","slug":"mybatis-%e5%a4%9a%e6%9d%a1%e4%bb%b6%e6%9f%a5%e8%af%a2%e3%80%81%e5%8a%a8%e6%80%81sql%e3%80%81%e5%a4%9a%e8%a1%a8%e6%93%8d%e4%bd%9c%e3%80%81%e6%b3%a8%e8%a7%a3%e5%bc%80%e5%8f%91%ef%bc%8c%e5%ba%94%e6%9c%89","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10006600","title":{"rendered":"MyBatis \u591a\u6761\u4ef6\u67e5\u8be2\u3001\u52a8\u6001SQL\u3001\u591a\u8868\u64cd\u4f5c\u3001\u6ce8\u89e3\u5f00\u53d1\uff0c\u5e94\u6709\u5c3d\u6709\uff0c\u4e00\u7f51\u6253\u5c3d\uff01"},"content":{"rendered":"

\u6765\u6e90\uff1aiyu77.blog.csdn.net\/article\/details\/125761737<\/p>\n

MyBatis\u5c01\u88c5\u4e86JDBC\u901a\u8fc7Mapper\u4ee3\u7406\u7684\u65b9\u5f0f\uff0c\u4ee5\u524d\u7e41\u7410\u7684\u64cd\u4f5c\u901a\u8fc7\u201c\u5c5e\u6027\u4e0e\u5b57\u6bb5\u6620\u5c04\u201d\u5c31\u7b80\u5355\u5316\u89e3\uff0cMyBatis\u7684\u52a8\u6001SQL\u5b8c\u7f8e\u5c55\u73b0\u4e86DBMS\u7684\u72ec\u7279\u9b45\u529b<\/p>\n

\u4e00\u3001\u591a\u6761\u4ef6\u67e5\u8be2<\/h2>\n

\u57fa\u4e8eMybatis\u7684\u591a\u6761\u4ef6\u67e5\u8be2\uff0c\u662f\u5728Mapper\u4ee3\u7406\u7684\u6620\u5c04\u6587\u4ef6\u4e2d\u5199\u4e0a\u539f\u6709\u7684SQL\uff0c\u7136\u540e\u63a5\u53e3\u4e2d\u5199\u4e00\u4e2a\u5e26\u53c2\u7684\u65b9\u6cd5\u5373\u53ef\uff0c\u5c31\u50cf\u8fd9\u6837\uff1a<\/p>\n

\"\"<\/p>\n

\u76f8\u6bd4\u4e8e\u539f\u751f\u7684JDBC\u90a3\u4e00\u5957\uff0c\u901a\u8fc7MyBatis\u786e\u5b9e\u89e3\u51b3\u4e86\u4e0d\u5c11\u786c\u7f16\u7801\u7684\u95ee\u9898<\/p>\n

\u4f46\u662f\u7528\u6237\u7684\u67e5\u8be2\u6c38\u8fdc\u662f\u52a8\u6001\u7684\u64cd\u4f5c\uff0c\u4ed6\u53ef\u80fd\u5728\u591a\u4e2a\u6761\u4ef6\u4e2d\u9009\u62e9\u5176\u4e2d\u5c11\u91cf\u6761\u4ef6\u8fdb\u884c\u67e5\u8be2\uff0c\u6211\u4eec\u7684SQL\u662f\u6b7b\u7684\uff0c\u800c\u7528\u6237\u9700\u6c42\u5bf9\u5e94\u7684SQL\u5374\u662f\u6d3b\u7684\uff0c\u8fd9\u6837\u5c31\u4f1a\u9020\u6210\u4e0d\u5339\u914d\u800c\u5f62\u6210\u8bed\u6cd5\u9519\u8bef<\/p>\n

\u6bd4\u5982\uff0c\u6839\u636e\u8fd9\u5f20\u8868\uff0c\u82e5\u662f\u8981\u6839\u636e\u90e8\u5206\u5b57\u6bb5\u67e5\u51fa\u6574\u4f53\uff0c\u6211\u4eec\u53ef\u4ee5\u5199\u5bf9\u5e94\u9700\u6c42\u7684SQL\uff0c\u4f46\u662f\u6211\u8981\u662f\u67e5\u8be2\u7684\u6761\u4ef6\u53d8\u5c11\u4e86\u6216\u8005\u53d8\u591a\u4e86\u5462\uff1f\u82e5\u7528\u6237\u53ea\u60f3\u901a\u8fc7\u4e00\u4e2a\u6761\u4ef6\u6765\u67e5\u8be2\uff0c\u90a3\u4e48\u5728\u5176\u4ed6\u5360\u4f4d\u7b26\u7684\u4f4d\u7f6e\u4e0d\u8f93\u5165\u4e8e\u662f\u6210\u4e86null\uff0c\u8fc7\u4e0d\u4e86\u8bed\u6cd5\u81ea\u7136\u67e5\u4e0d\u4e86\uff0c\u8fd8\u5f97\u91cd\u65b0\u5199SQL\uff0c\u591a\u9ebb\u70e6<\/p>\n

\"\"<\/p>\n

\u8fd9\u4e2a\u65f6\u5019MyBatis\u7684\u7279\u8272\u5c31\u4f53\u73b0\u51fa\u6765\u4e86\u2014\u2014\u52a8\u6001SQL<\/p>\n

\u4e8c\u3001\u52a8\u6001SQL<\/h2>\n

SQL\u8bed\u53e5\u4f1a\u968f\u7740\u7528\u6237\u7684\u8f93\u5165\u6216\u8005\u5916\u90e8\u6761\u4ef6\u7684\u53d8\u5316\u800c\u53d8\u5316\uff0c\u5219\u79f0\u4e4b\u4e3a\u52a8\u6001SQL<\/p>\n

1. if-where<\/h3>\n

\u56e0\u4e3a\u91c7\u7528\u4e86Mapper\u4ee3\u7406\u5f00\u53d1\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5199xml\u7684\u5f62\u5f0f\u6765\u7f16\u5199\u6211\u4eec\u7684SQL\uff0c\u52a8\u6001SQL\u7684\u7279\u6027\u4e5f\u5c31\u5728\u8fd9\u4e00\u4e3e\u52a8\u4e2d\u6240\u8574\u80b2\uff0c\u5728\u539f\u6709\u7684Mapper\u6587\u4ef6\u91cc\u6211\u4eec\u8fdb\u884c\u5982\u4e0b\u6539\u9020\uff0c\u8ba9\u5e73\u5e73\u65e0\u5947\u7684SQL\u7115\u7136\u4e00\u65b0\uff1a<\/p>\n

<select id="selByCondition" resultMap="rm">\n    select *\n    from mybatis\n    <where>\n    <if test="status !=null">\n       and STATUS=#{STATUS}\n    <\/if>\n    <if test="companyName !=null and companyName !=''">\n    and company_name like #{companyName}\n    <\/if>\n    <if test="bracdName !=null and bracdName !=''">\n    and bracd_name like #{bracdName}\n    <\/if>\n    <\/where>\n<\/select><\/code><\/pre>\n
\u201c<where><\/code>\u6807\u7b7e\u53ef\u4ee5\u81ea\u52a8\u5e2e\u6211\u4eec\u53bb\u6389and\u201d\uff0c\u8fd9\u6837\uff0c\u4e0d\u7ba1\u67e5\u8be2\u7684\u6761\u4ef6\u600e\u4e48\u53d8\uff0c\u6211\u8ddf\u7740\u8fd9\u4e2a\u903b\u8f91\u6d41\u7a0b\u8d70\u5c31\u4e0d\u4f1a\u51fa\u73b0SQL\u8bed\u6cd5\u6bdb\u75c5\u800c\u5bfc\u81f4\u67e5\u8be2\u4e0d\u51fa\u6765\u7684\u6bdb\u75c5\u5566\uff0c\u56e0\u4e3anull\u7684\u60c5\u51b5\u5df2\u7ecf\u88abif\u6240\u8fc7\u6ee4\u6389\u4e86\uff0c\u771f\u662f\u592a\u54c7\u585e\u4e86\uff01<\/p>\n
\u63a8\u8350\u4e00\u4e2a\u5f00\u6e90\u514d\u8d39\u7684 Spring Boot \u6700\u5168\u6559\u7a0b\uff1a<\/p>\n
https:\/\/github.com\/javastacks…<\/a><\/p><\/blockquote>\n
2. choose-when-ortherwise<\/h3>\n
\u5bf9\u4e8e\u4ece\u591a\u4e2a\u6761\u4ef6\u4e2d\u9009\u62e9\u4e00\u4e2a\u7684\u5355\u6761\u4ef6\u67e5\u8be2\u7684\u573a\u666f\uff0c\u5229\u7528\u5206\u652f\u5d4c\u5957\u5c31\u53ef\u4ee5\u5b9e\u73b0\u52a8\u6001\u9009\u62e9\u5355\u6761\u4ef6\uff1a<\/p>\n
\u5728MyBatis\u7684Mapper\u4ee3\u7406\u4e2d\uff0c<choose><\/code>\u76f8\u5f53\u4e8eswitch\uff0c<when><\/code>\u76f8\u5f53\u4e8ecase<\/p>\n
<select id="selByCondition2" resultMap="rm">\n    select *\n    from mybatis where\n    <choose>\n        <when test="status !=null">\n            STATUS=#{STATUS}\n        <\/when>\n        <when test="companyName !=null and companyName !=''">\n            company_name like #{companyName}\n        <\/when>\n        <when test="bracdName !=null and bracdName !=''">\n            bracd_name like #{bracdName}\n        <\/when>\n        <otherwise>1=1<\/otherwise>\n    <\/choose>\n<\/select><\/code><\/pre>\n
\u4e0e\u591a\u6761\u4ef6\u67e5\u8be2\u4e0d\u540c\u7684\u662f\uff0cSQL\u8bed\u53e5\u4e2d\u53ea\u4f1a\u6709\u4e00\u4e2a\u5206\u652f\u751f\u6548<\/p>\n
\u5f53\u7528\u6237\u4e00\u4e2a\u6761\u4ef6\u90fd\u4e0d\u9009\u65f6\uff0c\u53ef\u4ee5\u5728<otherwise><\/code>\u4e2d\u5199\u4e0a1=1<\/code>\u8ba9\u8bed\u6cd5\u6210\u7acb\uff0c\u53cd\u4e4b\uff0c\u82e5\u9009\u62e9\u4e86\u6761\u4ef6\u5219\u4f1a\u8fd4\u56de\u6b63\u5e38\u7ed3\u679c<\/p>\n
3. foreach<\/h3>\n
\u5bf9\u4e8e\u6279\u91cf\u5220\u9664\u7684\u573a\u666f\uff0c\u4f20\u7edf\u7684\u65b9\u6cd5\u662f\u901a\u8fc7in\u5173\u952e\u5b57\u7ed3\u5408\u5360\u4f4d\u7b26\u6765\u786e\u5b9a\uff0c\u5c31\u50cf\u8fd9\u6837<\/p>\n
where id in (?,?,?)<\/code><\/pre>\n
\u4f46\u5bf9\u4e8e\u52a8\u6001\u7684\u573a\u666f\uff0c\u6279\u91cf\u7684\u6570\u91cf\u6c38\u8fdc\u662f\u4e0d\u786e\u5b9a\u7684\uff0c\u8fd9\u5c31\u5bfc\u81f4\u8fd8\u9700\u8981\u53bb\u6539SQL\u91cc\u7684\u5360\u4f4d\u7b26\u6570\u91cf\u554a\uff0c\u53c8\u662f\u4e00\u4ef6\u9ebb\u70e6\u4e8b<\/p>\n
PS:MyBatis\u4f1a\u5c06\u6570\u7ec4\u53c2\u6570\u5c01\u88c5\u6210\u4e00\u4e2aMap\u96c6\u5408\uff0c\u9ed8\u8ba4\u60c5\u51b5\uff08K-V\uff09array=\u6570\u7ec4<\/p><\/blockquote>\n
\u4e0b\u9762\u4f7f\u7528\u4e86@Param<\/code>\u6ce8\u89e3\u6539\u53d8\u4e86map\u96c6\u5408\u4e2d\u9ed8\u8ba4\u7684key<\/p>\n
\"\"<\/p>\n
\u4e8e\u662fMyBatis\u4e2d\u7684<foreach><\/code>\u89e3\u51b3\u4e86\u8fd9\u4e00\u9ebb\u70e6\uff1a<\/p>\n
\u672c\u8d28\u662f\u901a\u8fc7\u904d\u5386\u7684\u5f62\u5f0f\uff0c\u6279\u91cf\u5220\u9664\u7684\u6570\u636e\u662f\u7531id\u6570\u7ec4\u6216\u8005\u96c6\u5408\u6765\u51b3\u5b9a\uff0ccollection<\/code>\u5c5e\u6027\u51b3\u5b9a\u4e86\u8981\u904d\u5386\u54ea\u4e2a\u6570\u7ec4\/\u96c6\u5408\uff0citem\u5c5e\u6027\u5219\u6765\u5b58\u653e\u9009\u51fa\u7684\u5143\u7d20\uff0c\u5e76\u628a\u5b83\u653e\u5728\u5360\u4f4d\u7b26\u91cc\uff0cseparator<\/code>\u5c5e\u6027\u8868\u793a\u5206\u9694\u7b26<\/p>\n
<delete id="deleteById">\n    delete frpm mybatis where id in\n    <foreach collection="ids" item="id" separator="," open="(" close=")">\n        #{id}\n    <\/foreach>;\n<\/delete><\/code><\/pre>\n
\u6709\u4eba\u4f1a\u95ee\u4e3a\u5565\u8fd9\u91cc\u53ea\u6709\u4e00\u4e2a#{id}<\/code>\uff0c\u6211\u7684\u5c5e\u6027\u5b57\u6bb5\u4e0d\u6b62\u8fd9\u4e00\u4e2a\u5440\uff1f\u6b64id\u975e\u5f7cid\u4ed6\u662f\u4e00\u4e2a\u6570\u7ec4\/\u96c6\u5408<\/p>\n
\u4e09\u3001\u591a\u8868\u64cd\u4f5c<\/h2>\n
\u591a\u8868\u4e4b\u95f4\u7684\u5173\u7cfb\u6709\u4e00\u5bf9\u4e00\uff0c\u4e00\u5bf9\u591a\uff0c\u591a\u5bf9\u4e00\uff0c\u591a\u5bf9\u591a\uff0c\u6bcf\u4e00\u79cd\u90fd\u6709\u5efa\u8868\u7684\u539f\u5219,\u4ee5\u7528\u6237-\u8ba2\u5355\u6a21\u578b\u4e3a\u4f8b<\/p>\n
\u5229\u7528\u4f20\u7edf\u7684\u65b9\u6cd5\u8fdb\u884c\u591a\u8868\u67e5\u8be2\u65e0\u975e\u662f\u901a\u8fc7id\u6765\u8fde\u63a5\u8868\u7136\u540e\u5c01\u88c5\u8fd4\u56de\u7ed3\u679c\uff0cMyBatis\u4e2d\u4e5f\u662f\u5982\u6b64\uff0c\u6211\u4eec\u5728Mapper\u6587\u4ef6\u4e2d\u5199\u597d\u8868\u5b57\u6bb5\u4e4b\u95f4\u7684\u6620\u5c04\u5173\u7cfb\uff0c\u5b9a\u4e49\u597d\u7c7b\u578b\u5373\u53ef\uff0c\u53ea\u4e0d\u8fc7\u8fd9\u4e00\u8fc7\u7a0b\u6709\u70b9\u590d\u6742\uff0c\u4f46\u4e00\u6b21\u914d\u597d\u4e4b\u540e\u5373\u53ef\u6781\u5927\u51cf\u5c11\u786c\u7f16\u7801\u95ee\u9898\uff0c\u63d0\u9ad8\u6548\u7387<\/p>\n
1. \u4e00\u5bf9\u4e00<\/h3>\n
\u4e00\u4e2a\u7528\u6237\u6709\u4e00\u5f20\u8ba2\u5355<\/p>\n
\"\"<\/p>\n
\u9996\u5148\u8fd8\u662f\u90a3\u5957\u8def\uff0c\u5efa\u597d\u5b9e\u4f53\u7c7b\uff0c\u5199\u597d\u63a5\u53e3\u65b9\u6cd5\uff0c\u914d\u7f6eMapper\u6587\u4ef6\uff0c\u800c\u591a\u8868\u64cd\u4f5c\u7684\u9ebb\u70e6\u70b9\u5c31\u5728\u4e8e\u914d\u7f6e\u6587\u4ef6\uff0c\u8fd9\u91cc\u901a\u8fc7\u4f8b\u5b50\u7ec6\u8bf4\u4e00\u4e0b<\/p>\n
1.\u5148\u628a\u8868\u5199\u597d<\/h5>\n
CREATE TABLE orders (\nid INT PRIMARY KEY ,\nordertime VARCHAR(20) NOT NULL DEFAULT '',\ntotal DOUBLE,\nuid INT);\nINSERT INTO orders VALUES(1,2020,2000,1);\nINSERT INTO orders VALUES(2,2021,3000,2);\nINSERT INTO orders VALUES(3,2022,4000,3);\nCREATE TABLE USER (\nid INT PRIMARY KEY ,\nusername VARCHAR(50) NOT NULL DEFAULT '',\npasswords VARCHAR(50) NOT NULL DEFAULT '');\nINSERT INTO USER VALUES(1,'lyy',333);\nINSERT INTO USER VALUES(2,'myy',444);\nINSERT INTO USER VALUES(3,'xyy',555);<\/code><\/pre>\n
2.\u5199Mapper\u914d\u7f6e\u6587\u4ef6<\/h5>\n
\u5728\u5199\u5b9e\u4f53\u7c7b\u65f6\uff0c\u8981\u628a\u4e00\u4e2a\u5b9e\u4f53\u5199\u5230\u53e6\u4e00\u4e2a\u5b9e\u4f53\u7684\u5c5e\u6027\u91cc\u9762\uff0c\u8fd9\u6837\u624d\u4f53\u73b0\u5173\u8054\u6027\uff0c\u5c31\u6bd4\u5982\u201c\u8ba2\u5355\u662f\u6240\u7528\u6237\u62e5\u6709\u7684\u201d\uff0c\u6b63\u56e0\u4e3a\u8fd9\u79cd\u5173\u7cfb\u6211\u4eec\u624d\u4f1a\u5728\u8ba2\u5355\u5b9e\u4f53\u7c7b\u91cc\u9762\u5199\u4e0aprivate User user;<\/code>\u8fd9\u4e00\u5c5e\u6027\uff0c\u8fd9\u6837\u6839\u636eid\u8fde\u63a5\u7684\u4e24\u4e2a\u5b9e\u4f53\u624d\u80fd\u5b8c\u7f8e\u5bf9\u63a5\uff01<\/p>\n
\u5c31\u50cf\u8fd9\u6837\uff1a<\/p>\n
\"\"<\/p>\n
\u901a\u8fc7<association><\/code>\u628a\u4e24\u5f20\u8868\u5bf9\u5e94\u7684\u5b9e\u4f53\u7c7b\u8fde\u63a5\u8d77\u6765,\u53ea\u4e0d\u8fc7\u662f\u4e3b\u952eID\u8981\u7528\u5355\u72ec\u7684\u6807\u7b7e<\/p>\n