{"id":201026,"date":"2025-05-06T15:13:26","date_gmt":"2025-05-06T07:13:26","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201026\/"},"modified":"2025-05-06T15:13:26","modified_gmt":"2025-05-06T07:13:26","slug":"java-mybatis-%e6%9f%a5%e8%af%a2%e7%bb%93%e6%9e%9c%e4%b8%ba%e7%a9%ba%e5%80%bc%ef%bc%8c%e5%a6%82%e4%bd%95%e8%bf%94%e5%9b%9e%e6%9c%9f%e6%9c%9b%e7%9a%84-int-%e7%b1%bb%e5%9e%8b%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201026\/","title":{"rendered":"Java MyBatis \u67e5\u8be2\u7ed3\u679c\u4e3a\u7a7a\u503c\uff0c\u5982\u4f55\u8fd4\u56de\u671f\u671b\u7684 int \u7c7b\u578b\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>Java MyBatis \u67e5\u8be2\u7ed3\u679c\u4e3a\u7a7a\u503c\uff0c\u5982\u4f55\u8fd4\u56de\u671f\u671b\u7684 int \u7c7b\u578b\uff1f<\/h1>\n<p>\u7f16\u7a0b\u5e76\u4e0d\u662f\u4e00\u4e2a\u673a\u68b0\u6027\u7684\u5de5\u4f5c\uff0c\u800c\u662f\u9700\u8981\u6709\u601d\u8003\uff0c\u6709\u521b\u65b0\u7684\u5de5\u4f5c\uff0c\u8bed\u6cd5\u662f\u56fa\u5b9a\u7684\uff0c\u4f46\u89e3\u51b3\u95ee\u9898\u7684\u601d\u8def\u5219\u662f\u4f9d\u9760\u4eba\u7684\u601d\u7ef4\uff0c\u8fd9\u5c31\u9700\u8981\u6211\u4eec\u575a\u6301\u5b66\u4e60\u548c\u66f4\u65b0\u81ea\u5df1\u7684\u77e5\u8bc6\u3002\u4eca\u5929\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6574\u7406\u5206\u4eab\u300aJava MyBatis \u67e5\u8be2\u7ed3\u679c\u4e3a\u7a7a\u503c\uff0c\u5982\u4f55\u8fd4\u56de\u671f\u671b\u7684 int \u7c7b\u578b\uff1f\u300b\uff0c\u6587\u7ae0\u8bb2\u89e3\u7684\u77e5\u8bc6\u70b9\u4e3b\u8981\u5305\u62ec\uff0c\u5982\u679c\u4f60\u5bf9\u6570\u636e\u5e93\u65b9\u9762\u7684\u77e5\u8bc6\u70b9\u611f\u5174\u8da3\uff0c\u5c31\u4e0d\u8981\u9519\u8fc7\u4e3b\u673a\u5b9d\u8d1d\uff0c\u5728\u8fd9\u53ef\u4ee5\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u52a9\u529b\u5f00\u53d1\u80fd\u529b\u7684\u63d0\u5347\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241126\/17325939986745494e47750.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>java\u67e5\u8be2sql\u671f\u671b\u8fd4\u56deint\uff0c\u5904\u7406\u7a7a\u503c\u8fd4\u56de<\/strong><\/p>\n<p>\u5728\u4f7f\u7528mybatis\u8fdb\u884c\u6570\u636e\u67e5\u8be2\u65f6\uff0c\u5982\u679c\u671f\u671b\u8fd4\u56deint\u7c7b\u578b\u7684\u503c\uff0c\u4f46\u5b9e\u9645\u8fd4\u56denull\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u4e24\u79cd\u65b9\u6cd5\u6765\u8fdb\u884c\u5904\u7406\uff1a<\/p>\n<p><strong>1. \u4fee\u6539\u8fd4\u56de\u503c\u7c7b\u578b\u4e3ainteger<\/strong><\/p>\n<p>\u5c06\u67e5\u8be2\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u7c7b\u578b\u4eceint\u4fee\u6539\u4e3ainteger\uff0c\u8fd9\u6837\u5c31\u4e0d\u4f1a\u629b\u51fa\u5f02\u5e38\u3002\u5728\u4e1a\u52a1\u903b\u8f91\u5c42\u4e2d\uff0c\u53ef\u4ee5\u5224\u65ad\u8fd4\u56de\u7684\u503c\u662f\u5426\u4e3anull\uff0c\u5982\u679c\u662fnull\uff0c\u5219\u53ef\u4ee5\u8fd4\u56de0\u6216\u5176\u4ed6\u9ed8\u8ba4\u503c\u3002<\/p>\n<p><strong>2. \u4f7f\u7528\u6570\u636e\u5e93\u51fd\u6570\u5305\u88f9\u67e5\u8be2<\/strong><\/p>\n<p>\u53ef\u4ee5\u5728sql\u67e5\u8be2\u4e2d\u4f7f\u7528\u6570\u636e\u5e93\u51fd\u6570ifnull\u6216coalesce\u6765\u5305\u88f9max\u51fd\u6570\uff0c\u5c06null\u503c\u66ff\u6362\u4e3a\u9ed8\u8ba4\u503c\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\uff1a<\/p>\n<pre>@Select(\"SELECT max(id) FROM user\")\nInteger maxId();<\/pre>\n<p>\u8fd9\u6837\uff0c\u5982\u679c\u8868\u4e2d\u6ca1\u6709\u6570\u636e\uff0c\u67e5\u8be2\u5c06\u4f1a\u8fd4\u56de0\u800c\u4e0d\u662f\u62a5\u9519\u3002<\/p>\n<p>\u4eca\u5929\u5173\u4e8e\u300aJava MyBatis \u67e5\u8be2\u7ed3\u679c\u4e3a\u7a7a\u503c\uff0c\u5982\u4f55\u8fd4\u56de\u671f\u671b\u7684 int \u7c7b\u578b\uff1f\u300b\u7684\u5185\u5bb9\u5c31\u4ecb\u7ecd\u5230\u8fd9\u91cc\u4e86\uff0c\u662f\u4e0d\u662f\u5b66\u8d77\u6765\u4e00\u76ee\u4e86\u7136\uff01\u60f3\u8981\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u5185\u5bb9\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>Java MyBatis \u67e5\u8be2\u7ed3&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-201026","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201026","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=201026"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201026\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201026"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201026"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201026"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}