{"id":14220,"date":"2023-12-04T00:54:41","date_gmt":"2023-12-03T16:54:41","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=14220"},"modified":"2023-12-04T00:55:47","modified_gmt":"2023-12-03T16:55:47","slug":"mybatis-li-mian-de-dong-tai-sql-shi-zen-me-she-din","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/04\/mybatis-li-mian-de-dong-tai-sql-shi-zen-me-she-din\/","title":{"rendered":"MyBatis \u91cc\u9762\u7684\u52a8\u6001 Sql \u662f\u600e\u4e48\u8bbe\u5b9a\u7684\uff1f\u7528\u4ec0\u4e48\u8bed\u6cd5\uff1f"},"content":{"rendered":"

\u5728 MyBatis \u4e2d\uff0c\u52a8\u6001 SQL \u53ef\u4ee5\u4f7f\u7528 XML \u4e2d\u7684\u4e00\u4e9b\u7279\u6b8a\u5143\u7d20\u6765\u5b9e\u73b0\u6761\u4ef6\u5224\u65ad\u3001\u5faa\u73af\u7b49\u52a8\u6001\u6784\u5efa SQL \u8bed\u53e5\u7684\u529f\u80fd\u3002\u4ee5\u4e0b\u662f MyBatis \u4e2d\u5e38\u7528\u7684\u52a8\u6001 SQL \u5143\u7d20\uff1a<\/p>\n

    \n
  1. if \u5143\u7d20\uff1a<\/strong> \u7528\u4e8e\u6761\u4ef6\u5224\u65ad\uff0c\u6839\u636e\u6761\u4ef6\u52a8\u6001\u62fc\u63a5 SQL \u8bed\u53e5\u3002<\/li>\n<\/ol>\n
    <select id=\"getUserByCondition\" parameterType=\"map\" resultType=\"User\">\n    SELECT * FROM users\n    <where>\n        <if test=\"name != null\">\n            AND name = #{name}\n        <\/if>\n        <if test=\"age != null\">\n            AND age = #{age}\n        <\/if>\n    <\/where>\n<\/select>\n<\/code><\/pre>\n
      \n
    1. choose\u3001when\u3001otherwise \u5143\u7d20\uff1a<\/strong> \u7c7b\u4f3c\u4e8e switch-case \u7684\u9009\u62e9\u7ed3\u6784\u3002<\/li>\n<\/ol>\n
      <select id=\"getUserByCondition\" parameterType=\"map\" resultType=\"User\">\n    SELECT * FROM users\n    <where>\n        <choose>\n            <when test=\"name != null\">\n                AND name = #{name}\n            <\/when>\n            <when test=\"age != null\">\n                AND age = #{age}\n            <\/when>\n            <otherwise>\n                AND status = 'active'\n            <\/otherwise>\n        <\/choose>\n    <\/where>\n<\/select>\n<\/code><\/pre>\n
        \n
      1. trim\u3001where\u3001set \u5143\u7d20\uff1a<\/strong> \u7528\u4e8e\u5904\u7406 SQL \u8bed\u53e5\u4e2d\u7684\u7a7a\u767d\u5b57\u7b26\u3002<\/li>\n<\/ol>\n
        <update id=\"updateUser\" parameterType=\"User\">\n    UPDATE users\n    <set>\n        <if test=\"name != null\">name = #{name},<\/if>\n        <if test=\"age != null\">age = #{age},<\/if>\n    <\/set>\n    WHERE id = #{id}\n<\/update>\n<\/code><\/pre>\n
          \n
        1. foreach \u5143\u7d20\uff1a<\/strong> \u7528\u4e8e\u5faa\u73af\u5904\u7406\u96c6\u5408\uff0c\u751f\u6210 IN \u5b50\u53e5\u3002<\/li>\n<\/ol>\n
          <select id=\"getUsersByIdList\" parameterType=\"map\" resultType=\"User\">\n    SELECT * FROM users WHERE id IN\n    <foreach collection=\"ids\" item=\"id\" open=\"(\" separator=\",\" close=\")\">\n        #{id}\n    <\/foreach>\n<\/select>\n<\/code><\/pre>\n
          \u8fd9\u4e9b\u52a8\u6001 SQL \u5143\u7d20\u53ef\u4ee5\u5e2e\u52a9\u5f00\u53d1\u8005\u6839\u636e\u6761\u4ef6\u3001\u96c6\u5408\u7b49\u52a8\u6001\u6784\u5efa SQL \u8bed\u53e5\uff0c\u4f7f\u5f97 SQL \u7684\u751f\u6210\u66f4\u52a0\u7075\u6d3b\u548c\u4fbf\u6377\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
          \u5728 MyBatis \u4e2d\uff0c\u52a8\u6001 SQL \u53ef\u4ee5\u4f7f\u7528 XML \u4e2d\u7684\u4e00\u4e9b\u7279\u6b8a\u5143\u7d20\u6765\u5b9e\u73b0\u6761\u4ef6\u5224\u65ad\u3001\u5faa\u73af\u7b49\u52a8\u6001\u6784\u5efa SQL […]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[113],"tags":[],"class_list":["post-14220","post","type-post","status-publish","format-standard","hentry","category-mybatis"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/14220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=14220"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/14220\/revisions"}],"predecessor-version":[{"id":14221,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/14220\/revisions\/14221"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=14220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=14220"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=14220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}