{"id":169975,"date":"2024-11-06T20:06:20","date_gmt":"2024-11-06T12:06:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/169975\/"},"modified":"2024-11-06T20:06:21","modified_gmt":"2024-11-06T12:06:21","slug":"varchar2-%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b%e9%95%b7%e5%ba%a6%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7%e5%92%8c%e9%99%90%e5%88%b6-%e6%95%b8%e6%93%9a%e5%ba%ab-varchar2-%e9%95%b7%e5%ba%a6","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/169975\/","title":{"rendered":"VarChar2 \u6578\u64da\u985e\u578b\u9577\u5ea6\u7684\u91cd\u8981\u6027\u548c\u9650\u5236 (\u6578\u64da\u5eab varchar2 \u9577\u5ea6)"},"content":{"rendered":"<h1 id=\"varchar2-%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b%e9%95%b7%e5%ba%a6%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7%e5%92%8c%e9%99%90%e5%88%b6-%e6%95%b8%e6%93%9a%e5%ba%ab-varchar2-%e9%95%b7%e5%ba%a6-pFkGxroncc\">VarChar2 \u6578\u64da\u985e\u578b\u9577\u5ea6\u7684\u91cd\u8981\u6027\u548c\u9650\u5236 (\u6578\u64da\u5eab varchar2 \u9577\u5ea6)<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u5c0d\u65bc\u6578\u64da\u7684\u5b58\u5132\u548c\u8655\u7406\u81f3\u95dc\u91cd\u8981\u3002Oracle \u6578\u64da\u5eab\u4e2d\u7684 <code>VARCHAR2<\/code> \u6578\u64da\u985e\u578b\u662f\u4e00\u7a2e\u8b8a\u9577\u5b57\u7b26\u6578\u64da\u985e\u578b\uff0c\u5ee3\u6cdb\u7528\u65bc\u5b58\u5132\u53ef\u8b8a\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u3002\u672c\u6587\u5c07\u63a2\u8a0e <code>VARCHAR2<\/code> \u6578\u64da\u985e\u578b\u7684\u9577\u5ea6\u91cd\u8981\u6027\u53ca\u5176\u9650\u5236\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u6642\u505a\u51fa\u660e\u667a\u7684\u9078\u64c7\u3002<\/p>\n<h2 id=\"varchar2-%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-pFkGxroncc\">VARCHAR2 \u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p><code>VARCHAR2<\/code> \u662f Oracle \u6578\u64da\u5eab\u4e2d\u7528\u4f86\u5b58\u5132\u53ef\u8b8a\u9577\u5ea6\u5b57\u7b26\u4e32\u7684\u6578\u64da\u985e\u578b\u3002\u8207\u56fa\u5b9a\u9577\u5ea6\u7684 <code>CHAR<\/code> \u985e\u578b\u4e0d\u540c\uff0c<code>VARCHAR2<\/code> \u53ea\u4f54\u7528\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\uff0c\u52a0\u4e0a1\u62162\u500b\u5b57\u7bc0\u7684\u984d\u5916\u958b\u92b7\uff0c\u9019\u4f7f\u5f97\u5b83\u5728\u5b58\u5132\u6548\u7387\u4e0a\u66f4\u5177\u512a\u52e2\u3002<\/p>\n<h2 id=\"%e9%95%b7%e5%ba%a6%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7-pFkGxroncc\">\u9577\u5ea6\u7684\u91cd\u8981\u6027<\/h2>\n<p>\u5728\u5b9a\u7fa9 <code>VARCHAR2<\/code> \u7684\u9577\u5ea6\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u8003\u616e\u4ee5\u4e0b\u5e7e\u500b\u65b9\u9762\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u5b8c\u6574\u6027\uff1a<\/strong>\u9078\u64c7\u5408\u9069\u7684\u9577\u5ea6\u53ef\u4ee5\u9632\u6b62\u6578\u64da\u622a\u65b7\u6216\u6ea2\u51fa\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002\u4f8b\u5982\uff0c\u5982\u679c\u4e00\u500b\u5b57\u6bb5\u9810\u671f\u5b58\u5132\u7528\u6236\u540d\uff0c\u5247\u61c9\u6839\u64da\u5be6\u969b\u9700\u6c42\u8a2d\u7f6e\u5408\u7406\u7684\u9577\u5ea6\uff0c\u907f\u514d\u7528\u6236\u540d\u88ab\u622a\u65b7\u3002<\/li>\n<li><strong>\u6027\u80fd\u512a\u5316\uff1a<\/strong>\u904e\u9577\u7684 <code>VARCHAR2<\/code> \u5b9a\u7fa9\u53ef\u80fd\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\uff0c\u7279\u5225\u662f\u5728\u67e5\u8a62\u548c\u7d22\u5f15\u64cd\u4f5c\u4e2d\u3002\u5408\u7406\u7684\u9577\u5ea6\u8a2d\u7f6e\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11\u5167\u5b58\u4f7f\u7528\u3002<\/li>\n<li><strong>\u5b58\u5132\u7a7a\u9593\uff1a<\/strong>\u96d6\u7136 <code>VARCHAR2<\/code> \u662f\u53ef\u8b8a\u9577\u5ea6\u7684\uff0c\u4f46\u5982\u679c\u9577\u5ea6\u8a2d\u7f6e\u904e\u5927\uff0c\u53ef\u80fd\u6703\u5c0e\u81f4\u4e0d\u5fc5\u8981\u7684\u5b58\u5132\u7a7a\u9593\u6d6a\u8cbb\u3002\u6839\u64da\u5be6\u969b\u9700\u6c42\u8a2d\u7f6e\u9577\u5ea6\u53ef\u4ee5\u6709\u6548\u5229\u7528\u5b58\u5132\u8cc7\u6e90\u3002<\/li>\n<\/ul>\n<h2 id=\"%e9%95%b7%e5%ba%a6%e7%9a%84%e9%99%90%e5%88%b6-pFkGxroncc\">\u9577\u5ea6\u7684\u9650\u5236<\/h2>\n<p>\u5728 Oracle \u6578\u64da\u5eab\u4e2d\uff0c<code>VARCHAR2<\/code> \u7684\u9577\u5ea6\u9650\u5236\u53d6\u6c7a\u65bc\u6578\u64da\u5eab\u7684\u7248\u672c\uff1a<\/p>\n<ul>\n<li>\u5728 Oracle 12c \u4e4b\u524d\uff0c<code>VARCHAR2<\/code> \u7684\u6700\u5927\u9577\u5ea6\u70ba 4000 \u5b57\u7b26\u3002<\/li>\n<li>\u5728 Oracle 12c \u53ca\u4ee5\u5f8c\u7684\u7248\u672c\u4e2d\uff0c\u82e5\u555f\u7528\u64f4\u5c55\u7684 <code>VARCHAR2<\/code> \u529f\u80fd\uff0c\u6700\u5927\u9577\u5ea6\u53ef\u9054 32767 \u5b57\u7b26\u3002<\/li>\n<\/ul>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u7576\u4f7f\u7528\u64f4\u5c55\u7684 <code>VARCHAR2<\/code> \u6642\uff0c\u5fc5\u9808\u5728\u6578\u64da\u5eab\u7d1a\u5225\u555f\u7528\u6b64\u529f\u80fd\uff0c\u4e26\u4e14\u5728\u5275\u5efa\u8868\u6642\u6307\u5b9a\u76f8\u61c9\u7684\u53c3\u6578\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%a4%ba%e4%be%8b-pFkGxroncc\">\u4f7f\u7528\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u5275\u5efa\u8868\u7684\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4f7f\u7528 <code>VARCHAR2<\/code> \u6578\u64da\u985e\u578b\uff1a<\/p>\n<pre><code>CREATE TABLE users (\n    user_id NUMBER PRIMARY KEY,\n    username VARCHAR2(50),\n    email VARCHAR2(100)\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>username<\/code> \u7684\u9577\u5ea6\u8a2d\u7f6e\u70ba 50\uff0c<code>email<\/code> \u7684\u9577\u5ea6\u8a2d\u7f6e\u70ba 100\uff0c\u9019\u4e9b\u9577\u5ea6\u662f\u6839\u64da\u5be6\u969b\u9700\u6c42\u9032\u884c\u8a2d\u7f6e\u7684\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-pFkGxroncc\">\u7d50\u8ad6<\/h2>\n<p>\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u6642\uff0c\u9078\u64c7\u5408\u9069\u7684 <code>VARCHAR2<\/code> \u9577\u5ea6\u5c0d\u65bc\u6578\u64da\u7684\u5b8c\u6574\u6027\u3001\u6027\u80fd\u548c\u5b58\u5132\u7a7a\u9593\u7684\u6709\u6548\u5229\u7528\u81f3\u95dc\u91cd\u8981\u3002\u958b\u767c\u8005\u61c9\u6839\u64da\u5be6\u969b\u9700\u6c42\u4ed4\u7d30\u8003\u616e\u9577\u5ea6\u8a2d\u7f6e\uff0c\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u622a\u65b7\u548c\u6027\u80fd\u554f\u984c\u3002\u4e86\u89e3 <code>VARCHAR2<\/code> \u7684\u9577\u5ea6\u9650\u5236\u548c\u4f7f\u7528\u65b9\u6cd5\uff0c\u5c07\u6709\u52a9\u65bc\u66f4\u597d\u5730\u8a2d\u8a08\u548c\u7ba1\u7406\u6578\u64da\u5eab\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u548c\u6578\u64da\u5eab\u7ba1\u7406\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3VarChar2\u6578\u64da\u985e\u578b\u7684\u9577\u5ea6\u91cd\u8981\u6027\u53ca\u5176\u9650\u5236\uff0c\u78ba\u4fdd\u6578\u64da\u5eab\u8a2d\u8a08\u7684\u6709\u6548\u6027\u8207\u6027\u80fd\u512a\u5316\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-169975","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/169975","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=169975"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/169975\/revisions"}],"predecessor-version":[{"id":169976,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/169975\/revisions\/169976"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=169975"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=169975"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=169975"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}