\u5728\u73fe\u4eca\u7684\u6578\u64da\u9a45\u52d5\u6642\u4ee3\uff0c\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09\u626e\u6f14\u8457\u81f3\u95dc\u91cd\u8981\u7684\u89d2\u8272\u3002SQL Server\u4f5c\u70ba\u4e00\u6b3e\u6d41\u884c\u7684\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u529f\u80fd\u5f37\u5927\u7684\u8173\u672c\u51fd\u6578\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u66f4\u9ad8\u6548\u5730\u8655\u7406\u6578\u64da\u3002\u672c\u6587\u5c07\u5206\u4eab\u56db\u500b\u5be6\u7528\u7684SQL Server\u8173\u672c\u51fd\u6578\uff0c\u5e6b\u52a9\u60a8\u63d0\u5347\u6578\u64da\u5eab\u64cd\u4f5c\u7684\u6548\u7387\u3002<\/p>\n
GETDATE() \u51fd\u6578\u7528\u65bc\u7372\u53d6\u7576\u524d\u7684\u7cfb\u7d71\u65e5\u671f\u548c\u6642\u9593\u3002\u9019\u5728\u9700\u8981\u8a18\u9304\u6578\u64da\u63d2\u5165\u6216\u66f4\u65b0\u6642\u9593\u7684\u60c5\u6cc1\u4e0b\u7279\u5225\u6709\u7528\u3002<\/p>\n
SELECT GETDATE() AS CurrentDateTime;<\/code><\/pre>\n\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u7576\u524d\u7684\u65e5\u671f\u548c\u6642\u9593\uff0c\u683c\u5f0f\u70ba YYYY-MM-DD HH:MM:SS.mmm\u3002\u60a8\u53ef\u4ee5\u5c07\u6b64\u51fd\u6578\u7528\u65bc\u63d2\u5165\u6216\u66f4\u65b0\u64cd\u4f5c\u4e2d\uff0c\u4ee5\u4fbf\u81ea\u52d5\u8a18\u9304\u6642\u9593\u6233\u3002<\/p>\n
2. LEN() \u51fd\u6578<\/h2>\n
LEN() \u51fd\u6578\u7528\u65bc\u8a08\u7b97\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002\u9019\u5728\u6578\u64da\u9a57\u8b49\u548c\u6e05\u7406\u904e\u7a0b\u4e2d\u975e\u5e38\u6709\u7528\uff0c\u7279\u5225\u662f\u7576\u60a8\u9700\u8981\u78ba\u4fdd\u67d0\u4e9b\u5b57\u6bb5\u7684\u5b57\u7b26\u6578\u91cf\u7b26\u5408\u8981\u6c42\u6642\u3002<\/p>\n
SELECT LEN('Hello, World!') AS StringLength;<\/code><\/pre>\n\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u5b57\u7b26\u4e32 “Hello, World!” \u7684\u9577\u5ea6\uff0c\u5373 13\u3002\u60a8\u53ef\u4ee5\u4f7f\u7528\u6b64\u51fd\u6578\u4f86\u6aa2\u67e5\u7528\u6236\u8f38\u5165\u7684\u6578\u64da\u662f\u5426\u7b26\u5408\u9810\u671f\u7684\u9577\u5ea6\u3002<\/p>\n
3. ISNULL() \u51fd\u6578<\/h2>\n
ISNULL() \u51fd\u6578\u7528\u65bc\u6aa2\u67e5\u4e00\u500b\u8868\u9054\u5f0f\u662f\u5426\u70ba NULL\uff0c\u4e26\u8fd4\u56de\u4e00\u500b\u66ff\u4ee3\u503c\u3002\u9019\u5728\u8655\u7406\u7f3a\u5931\u6578\u64da\u6642\u975e\u5e38\u6709\u7528\u3002<\/p>\n
SELECT ISNULL(column_name, 'Default Value') AS ColumnValue FROM table_name;<\/code><\/pre>\n\u5728\u9019\u6bb5\u4ee3\u78bc\u4e2d\uff0c\u5982\u679c column_name \u7684\u503c\u70ba NULL\uff0c\u5247\u5c07\u8fd4\u56de ‘Default Value’\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u5728\u67e5\u8a62\u7d50\u679c\u4e2d\u51fa\u73fe NULL \u503c\uff0c\u5f9e\u800c\u63d0\u9ad8\u6578\u64da\u7684\u53ef\u8b80\u6027\u3002<\/p>\n
4. CONVERT() \u51fd\u6578<\/h2>\n
CONVERT() \u51fd\u6578\u7528\u65bc\u5c07\u4e00\u7a2e\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u6578\u64da\u985e\u578b\u3002\u9019\u5728\u9700\u8981\u683c\u5f0f\u5316\u65e5\u671f\u6216\u8f49\u63db\u6578\u5b57\u985e\u578b\u6642\u7279\u5225\u6709\u7528\u3002<\/p>\n
SELECT CONVERT(VARCHAR, GETDATE(), 101) AS FormattedDate;<\/code><\/pre>\n\u9019\u6bb5\u4ee3\u78bc\u5c07\u7576\u524d\u65e5\u671f\u683c\u5f0f\u5316\u70ba MM\/DD\/YYYY \u7684\u5f62\u5f0f\u3002\u4f7f\u7528 CONVERT() \u51fd\u6578\u53ef\u4ee5\u6839\u64da\u9700\u6c42\u9748\u6d3b\u5730\u8abf\u6574\u6578\u64da\u7684\u986f\u793a\u683c\u5f0f\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u4ee5\u4e0a\u4ecb\u7d39\u7684\u56db\u500b SQL Server \u8173\u672c\u51fd\u6578\uff0cGETDATE()\u3001LEN()\u3001ISNULL() \u548c CONVERT()\uff0c\u90fd\u662f\u65e5\u5e38\u6578\u64da\u5eab\u64cd\u4f5c\u4e2d\u975e\u5e38\u5be6\u7528\u7684\u5de5\u5177\u3002\u638c\u63e1\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u66f4\u9ad8\u6548\u5730\u8655\u7406\u6578\u64da\uff0c\u63d0\u5347\u5de5\u4f5c\u6548\u7387\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f \u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u63a2\u7d22\u56db\u500b\u5be6\u7528\u7684SQL Server\u8173\u672c\u51fd\u6578\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7ba1\u7406\u6548\u7387\uff0c\u7c21\u5316\u67e5\u8a62\u548c\u6578\u64da\u8655\u7406\u904e\u7a0b\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-185900","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185900","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=185900"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185900\/revisions"}],"predecessor-version":[{"id":185901,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185900\/revisions\/185901"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=185900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=185900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=185900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}