{"id":168363,"date":"2024-11-06T11:45:20","date_gmt":"2024-11-06T03:45:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168363\/"},"modified":"2024-11-06T11:45:21","modified_gmt":"2024-11-06T03:45:21","slug":"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad-navarchar-%e5%ad%97%e6%ae%b5%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc-sql-%e6%95%b8%e6%93%9a%e5%ba%ab-navarchar-%e6%9b%b4%e5%a4%a7","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168363\/","title":{"rendered":"SQL \u6578\u64da\u5eab\u4e2d navarchar \u5b57\u6bb5\u7684\u66f4\u5927\u503c (sql \u6578\u64da\u5eab navarchar \u66f4\u5927)"},"content":{"rendered":"<h1 id=\"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad-navarchar-%e5%ad%97%e6%ae%b5%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc-iefzbOPbNC\">SQL \u6578\u64da\u5eab\u4e2d navarchar \u5b57\u6bb5\u7684\u66f4\u5927\u503c<\/h1>\n<p>\u5728 SQL \u6578\u64da\u5eab\u4e2d\uff0c<code>nvarchar<\/code> \u5b57\u6bb5\u662f\u4e00\u7a2e\u7528\u65bc\u5b58\u5132 Unicode \u5b57\u7b26\u7684\u6578\u64da\u985e\u578b\uff0c\u9019\u4f7f\u5f97\u5b83\u80fd\u5920\u652f\u6301\u591a\u7a2e\u8a9e\u8a00\u7684\u5b57\u7b26\u96c6\u3002\u9019\u5c0d\u65bc\u9700\u8981\u8655\u7406\u591a\u8a9e\u8a00\u6578\u64da\u7684\u61c9\u7528\u7a0b\u5e8f\u4f86\u8aaa\u5c24\u70ba\u91cd\u8981\u3002\u672c\u6587\u5c07\u63a2\u8a0e <code>nvarchar<\/code> \u5b57\u6bb5\u7684\u66f4\u5927\u503c\u53ca\u5176\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-nvarchar%ef%bc%9f-iefzbOPbNC\">\u4ec0\u9ebc\u662f nvarchar\uff1f<\/h2>\n<p><code>nvarchar<\/code> \u662f SQL Server \u4e2d\u7684\u4e00\u7a2e\u6578\u64da\u985e\u578b\uff0c\u5c08\u9580\u7528\u65bc\u5b58\u5132\u8b8a\u9577\u7684 Unicode \u5b57\u7b26\u4e32\u3002\u8207 <code>varchar<\/code> \u4e0d\u540c\uff0c<code>nvarchar<\/code> \u53ef\u4ee5\u5b58\u5132\u4efb\u4f55\u8a9e\u8a00\u7684\u5b57\u7b26\uff0c\u9019\u4f7f\u5f97\u5b83\u5728\u5168\u7403\u5316\u61c9\u7528\u4e2d\u975e\u5e38\u6709\u7528\u3002<code>nvarchar<\/code> \u7684\u5927\u5c0f\u53ef\u4ee5\u5f9e 1 \u5230 4,000 \u5b57\u7b26\uff0c\u4e26\u4e14\u53ef\u4ee5\u4f7f\u7528 <code>nvarchar(max)<\/code> \u4f86\u5b58\u5132\u66f4\u5927\u7684\u6578\u64da\uff0c\u6700\u591a\u53ef\u9054 2^31-1 \u5b57\u7b26\u3002<\/p>\n<h2 id=\"nvarchar-%e7%9a%84%e5%a4%a7%e5%b0%8f%e9%99%90%e5%88%b6-iefzbOPbNC\">nvarchar \u7684\u5927\u5c0f\u9650\u5236<\/h2>\n<p>\u5728 SQL Server \u4e2d\uff0c<code>nvarchar<\/code> \u5b57\u6bb5\u7684\u5927\u5c0f\u9650\u5236\u53d6\u6c7a\u65bc\u5176\u5b9a\u7fa9\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u5b9a\u7fa9\uff1a<\/p>\n<ul>\n<li><code>nvarchar(n)<\/code>\uff1a\u9019\u88e1\u7684 <code>n<\/code> \u662f\u5b57\u7b26\u6578\uff0c\u7bc4\u570d\u5f9e 1 \u5230 4,000\u3002<\/li>\n<li><code>nvarchar(max)<\/code>\uff1a\u9019\u500b\u5b9a\u7fa9\u5141\u8a31\u5b58\u5132\u6700\u591a 2^31-1 \u5b57\u7b26\uff0c\u9069\u5408\u9700\u8981\u5b58\u5132\u5927\u91cf\u6587\u672c\u7684\u60c5\u6cc1\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u5275\u5efa\u4e00\u500b\u53ef\u4ee5\u5b58\u5132\u6700\u591a 1000 \u500b\u5b57\u7b26\u7684 <code>nvarchar<\/code> \u5b57\u6bb5\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u8a9e\u53e5\uff1a<\/p>\n<pre><code>CREATE TABLE ExampleTable (\n    ExampleColumn NVARCHAR(1000)\n);<\/code><\/pre>\n<h2 id=\"%e4%bd%bf%e7%94%a8-nvarcharmax-%e7%9a%84%e6%83%85%e6%b3%81-iefzbOPbNC\">\u4f7f\u7528 nvarchar(max) \u7684\u60c5\u6cc1<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u5b58\u5132\u8d85\u904e 4,000 \u500b\u5b57\u7b26\u7684\u6578\u64da\u3002\u9019\u6642\u5019\uff0c\u4f7f\u7528 <code>nvarchar(max)<\/code> \u662f\u4e00\u500b\u5408\u9069\u7684\u9078\u64c7\u3002\u4f8b\u5982\uff0c\u7576\u60a8\u9700\u8981\u5b58\u5132\u7528\u6236\u7684\u8a55\u8ad6\u3001\u6587\u7ae0\u5167\u5bb9\u6216\u5176\u4ed6\u9577\u6587\u672c\u6642\uff0c<code>nvarchar(max)<\/code> \u53ef\u4ee5\u63d0\u4f9b\u66f4\u5927\u7684\u9748\u6d3b\u6027\u3002<\/p>\n<pre><code>CREATE TABLE Comments (\n    CommentID INT PRIMARY KEY,\n    UserComment NVARCHAR(MAX)\n);<\/code><\/pre>\n<h2 id=\"%e6%80%a7%e8%83%bd%e8%80%83%e9%87%8f-iefzbOPbNC\">\u6027\u80fd\u8003\u91cf<\/h2>\n<p>\u96d6\u7136 <code>nvarchar(max)<\/code> \u63d0\u4f9b\u4e86\u66f4\u5927\u7684\u9748\u6d3b\u6027\uff0c\u4f46\u5728\u6027\u80fd\u65b9\u9762\u4e5f\u9700\u8981\u8b39\u614e\u8003\u91cf\u3002\u4f7f\u7528 <code>nvarchar(max)<\/code> \u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\uff0c\u7279\u5225\u662f\u5728\u9032\u884c\u67e5\u8a62\u548c\u7d22\u5f15\u6642\u3002\u56e0\u6b64\uff0c\u5efa\u8b70\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u6642\uff0c\u6839\u64da\u5be6\u969b\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-iefzbOPbNC\">\u7d50\u8ad6<\/h2>\n<p>\u5728 SQL \u6578\u64da\u5eab\u4e2d\uff0c<code>nvarchar<\/code> \u5b57\u6bb5\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u652f\u6301\u591a\u8a9e\u8a00\u5b57\u7b26\u7684\u5b58\u5132\u3002\u9078\u64c7\u5408\u9069\u7684\u5927\u5c0f\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u53ef\u64f4\u5c55\u6027\u81f3\u95dc\u91cd\u8981\u3002\u7121\u8ad6\u662f\u4f7f\u7528 <code>nvarchar(n)<\/code> \u9084\u662f <code>nvarchar(max)<\/code>\uff0c\u90fd\u61c9\u6839\u64da\u5177\u9ad4\u7684\u61c9\u7528\u9700\u6c42\u4f86\u9032\u884c\u8a2d\u8a08\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u5c0f\u578b\u7db2\u7ad9\u9084\u662f\u5927\u578b\u61c9\u7528\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3 SQL \u6578\u64da\u5eab\u4e2d nvarchar \u5b57\u6bb5\u7684\u6700\u5927\u503c\uff0c\u63a2\u7d22\u5176\u5c0d\u6578\u64da\u5b58\u5132\u548c\u6027\u80fd\u7684\u5f71\u97ff\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-168363","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168363","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=168363"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168363\/revisions"}],"predecessor-version":[{"id":168364,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168363\/revisions\/168364"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}