{"id":2814,"date":"2023-04-27T13:52:35","date_gmt":"2023-04-27T05:52:35","guid":{"rendered":"https:\/\/hsin-life.com\/?p=2814"},"modified":"2023-04-27T13:52:36","modified_gmt":"2023-04-27T05:52:36","slug":"%e4%bd%bf%e7%94%a8-mybatis-%e6%a8%99%e7%b1%a4%e5%84%aa%e5%8c%96%e5%8b%95%e6%85%8b-sql-%e6%9f%a5%e8%a9%a2","status":"publish","type":"post","link":"https:\/\/hsin-life.com\/archives\/2814","title":{"rendered":"\u4f7f\u7528 MyBatis <where> \u6a19\u7c64\u512a\u5316\u52d5\u614b SQL \u67e5\u8a62<\/where>"},"content":{"rendered":"\n<p>\u5728\u5be6\u969b\u5de5\u4f5c\u4e2d\uff0c\u6211\u5011\u7d93\u5e38\u9700\u8981\u4f7f\u7528\u52d5\u614b SQL \u4f86\u6eff\u8db3\u591a\u689d\u4ef6\u67e5\u8a62\u7684\u9700\u6c42\u3002<\/p>\n\n\n\n<p>\u7136\u800c\uff0c\u9019\u6a23\u7684\u67e5\u8a62\u8a9e\u53e5\u5f80\u5f80\u5bb9\u6613\u51fa\u73fe\u932f\u8aa4\uff0c\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;select id=\"selectUserByUsernameAndSex\" resultType=\"user\" parameterType=\"com.ztt.User\">\r\n  select * \r\n  from user \r\n  where\r\n  &lt;if test=\"username != null\">\r\n  username=#{username}\r\n  &lt;\/if>\r\n  &lt;if test=\"username != null\">\r\n  and sex=#{sex}\r\n  &lt;\/if>\r\n&lt;\/select>\r\n<\/code><\/pre>\n\n\n\n<p>\u5982\u679c\u6c92\u6709\u5339\u914d\u7684\u689d\u4ef6\uff0c\u6700\u7d42\u9019\u689d SQL \u6703\u8b8a\u6210\uff1a<code>select * from user where<\/code>\uff1b\u5982\u679c username \u70ba\u7a7a\uff0c\u5247\u6703\u8b8a\u6210\uff1a<code>select * from user where and sex=#{sex}<\/code>\u3002<\/p>\n\n\n\n<p>\u9019\u5169\u7a2e\u60c5\u6cc1\u90fd\u6703\u7522\u751f\u932f\u8aa4\u7684 SQL \u8a9e\u53e5\u3002<\/p>\n\n\n\n<p>\u70ba\u4e86\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff0c\u6709\u4eba\u63d0\u51fa\u4e86\u5728 where \u5b50\u53e5\u4e2d\u52a0\u5165 1=1 \u7684\u689d\u4ef6\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;select id=\"selectUserByUsernameAndSex\" resultType=\"user\" parameterType=\"com.ztt.User\">\r\n  select * \r\n  from user \r\n  where\r\n  1 = 1\r\n  &lt;if test=\"username != null\">\r\n  and username=#{username}\r\n  &lt;\/if>\r\n  &lt;if test=\"username != null\">\r\n  and sex=#{sex}\r\n  &lt;\/if>\r\n&lt;\/select>\r\n<\/code><\/pre>\n\n\n\n<p>\u9019\u6a23\u4e00\u4f86\uff0c\u4e0d\u7ba1 if \u6a19\u7c64\u5167\u7684\u5224\u65b7\u5982\u4f55\uff0c\u90fd\u80fd\u4fdd\u8b49\u6700\u7d42\u7684 SQL \u8a9e\u53e5\u662f\u6b63\u78ba\u7684\u3002<\/p>\n\n\n\n<p>\u7136\u800c\uff0c\u9019\u6a23\u7684\u505a\u6cd5\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u640d\u5931\uff0c\u56e0\u70ba\u6dfb\u52a0\u4e86 &#8220;where 1=1&#8221; \u7684\u904e\u6ffe\u689d\u4ef6\u4e4b\u5f8c\uff0c\u6578\u64da\u5eab\u7cfb\u7d71\u7121\u6cd5\u4f7f\u7528\u7d22\u5f15\u7b49\u67e5\u8a62\u512a\u5316\u7b56\u7565\uff0c\u9700\u8981\u5c0d\u6bcf\u884c\u6578\u64da\u9032\u884c\u5168\u8868\u6383\u63cf\u3002<\/p>\n\n\n\n<p>\u5be6\u969b\u4e0a\uff0c\u7d93\u904e\u6578\u64da\u5eab\u7cfb\u7d71\u89e3\u6790\u512a\u5316\uff0c1=1 \u9019\u985e\u7121\u610f\u7fa9\u7684\u689d\u4ef6\u5c07\u6703\u88ab\u53bb\u9664\uff0c\u4e0d\u5f71\u97ff\u67e5\u8a62\u6548\u7387\u3002<\/p>\n\n\n\n<p>\u4f46\u662f\uff0c\u70ba\u4e86\u66f4\u597d\u5730\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 MyBatis \u7684 &lt;where> \u6a19\u7c64\u4f86\u512a\u5316\u67e5\u8a62\u8a9e\u53e5\u3002<\/p>\n\n\n\n<p><code>&lt;where><\/code> \u6a19\u7c64\u53ea\u6709\u5728\u5b83\u5305\u542b\u7684\u6a19\u7c64\u6709\u8fd4\u56de\u503c\u7684\u60c5\u6cc1\u4e0b\u624d\u63d2\u5165 &#8220;WHERE&#8221; \u5b50\u53e5\u3002\u800c\u4e14\uff0c\u5982\u679c\u5b50\u53e5\u7684\u958b\u982d\u70ba &#8220;AND&#8221; \u6216 &#8220;OR&#8221;\uff0c<code>&lt;where><\/code> \u6a19\u7c64\u4e5f\u6703\u5c07\u5b83\u5011\u53bb\u9664\u3002<\/p>\n\n\n\n<p>\u9019\u6a23\u5c31\u80fd\u4fdd\u8b49\u751f\u6210\u7684 SQL \u8a9e\u53e5\u662f\u6b63\u78ba\u7684\u3002<\/p>\n\n\n\n<p>\u4f7f\u7528 <code>&lt;where><\/code> \u6a19\u7c64\u5f8c\uff0c\u6211\u5011\u7684 SQL \u67e5\u8a62\u8a9e\u53e5\u8b8a\u6210\u4e86\u5982\u4e0b\u5f62\u5f0f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;select id=\"selectUserByUsernameAndSex\" resultType=\"user\" parameterType=\"com.ztt.User\">\r\n  select * from user\r\n  &lt;where>\r\n  &lt;if test=\"username != null\">\r\n  username=#{username}\r\n  &lt;\/if>\r\n  &lt;if test=\"username != null\">\r\n  and sex=#{sex}\r\n  &lt;\/if>\r\n  &lt;\/where>\r\n&lt;\/select>\r\n<\/code><\/pre>\n\n\n\n<p>\u9019\u6a23\uff0c\u5373\u4f7f\u689d\u4ef6\u5224\u65b7\u7d50\u679c\u70ba\u7a7a\uff0c\u751f\u6210\u7684 SQL \u8a9e\u53e5\u4e5f\u662f\u6b63\u78ba\u7684\u3002<\/p>\n\n\n\n<p>\u6b64\u5916\uff0c\u4f7f\u7528 <code>&lt;where><\/code> \u6a19\u7c64\u9084\u80fd\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u56e0\u70ba\u5b83\u53ef\u4ee5\u5145\u5206\u5229\u7528\u6578\u64da\u5eab\u7cfb\u7d71\u7684\u7d22\u5f15\u548c\u67e5\u8a62\u512a\u5316\u7b56\u7565\u3002<\/p>\n\n\n\n<p>\u7e3d\u7d50\uff0c\u4f7f\u7528 MyBatis \u7684 <code>&lt;where><\/code> \u6a19\u7c64\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u512a\u5316\u52d5\u614b SQL \u67e5\u8a62\u8a9e\u53e5\uff0c\u907f\u514d\u56e0\u689d\u4ef6\u5224\u65b7\u5c0e\u81f4\u7684\u932f\u8aa4 SQL \u8a9e\u53e5\uff0c\u540c\u6642\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\uff0c\u5728\u5be6\u969b\u958b\u767c\u904e\u7a0b\u4e2d\uff0c\u6211\u5011\u61c9\u5145\u5206\u5229\u7528 <code>&lt;where><\/code> \u6a19\u7c64\u4f86\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u548c\u8a9e\u53e5\u7684\u53ef\u8b80\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u4ecb\u7d39\u4e86\u5982\u4f55\u4f7f\u7528 MyBatis \u7684 <where> \u6a19\u7c64\u4f86\u512a\u5316\u52d5\u614b SQL \u67e5\u8a62\uff0c\u89e3\u6c7a\u56e0\u689d\u4ef6\u5224\u65b7\u5c0e\u81f4\u7684\u932f\u8aa4 SQL \u8a9e\u53e5\u554f\u984c\uff0c\u4e26\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n","protected":false},"author":1,"featured_media":2815,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[145],"tags":[704,709,706,710],"aioseo_notices":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/hsin-life.com\/wp-content\/uploads\/2023\/04\/pexels-photo-577585-2.jpeg?fit=1734%2C1300&ssl=1","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/posts\/2814"}],"collection":[{"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/comments?post=2814"}],"version-history":[{"count":0,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/posts\/2814\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/media\/2815"}],"wp:attachment":[{"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/media?parent=2814"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/categories?post=2814"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hsin-life.com\/wp-json\/wp\/v2\/tags?post=2814"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}