{"id":168415,"date":"2024-11-06T12:11:26","date_gmt":"2024-11-06T04:11:26","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168415\/"},"modified":"2024-11-06T12:11:27","modified_gmt":"2024-11-06T04:11:27","slug":"sql-%e5%be%aa%e7%92%b0%e5%9f%b7%e8%a1%8c-while-%e6%8e%a7%e5%88%b6","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168415\/","title":{"rendered":"SQL \u5faa\u74b0\u57f7\u884c while \u63a7\u5236"},"content":{"rendered":"<h1 id=\"sql-%e5%be%aa%e7%92%b0%e5%9f%b7%e8%a1%8c-while-%e6%8e%a7%e5%88%b6-PFhXZqdyDj\">SQL \u5faa\u74b0\u57f7\u884c while \u63a7\u5236<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u67e5\u8a62\u548c\u64cd\u4f5c\u8cc7\u6599\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u7576\u9700\u8981\u91cd\u8907\u57f7\u884c\u67d0\u4e9b\u64cd\u4f5c\u6642\uff0c\u5faa\u74b0\u63a7\u5236\u7d50\u69cb\u8b8a\u5f97\u975e\u5e38\u91cd\u8981\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e SQL \u4e2d\u7684 while \u5faa\u74b0\u63a7\u5236\uff0c\u4e26\u63d0\u4f9b\u76f8\u95dc\u7684\u7bc4\u4f8b\u548c\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-while-%e5%be%aa%e7%92%b0%ef%bc%9f-PFhXZqdyDj\">\u4ec0\u9ebc\u662f while \u5faa\u74b0\uff1f<\/h2>\n<p>while \u5faa\u74b0\u662f\u4e00\u7a2e\u63a7\u5236\u7d50\u69cb\uff0c\u5141\u8a31\u5728\u6eff\u8db3\u7279\u5b9a\u689d\u4ef6\u7684\u60c5\u6cc1\u4e0b\u91cd\u8907\u57f7\u884c\u4e00\u6bb5\u7a0b\u5f0f\u78bc\u3002\u9019\u5728\u9700\u8981\u6839\u64da\u67d0\u4e9b\u689d\u4ef6\u9032\u884c\u91cd\u8907\u64cd\u4f5c\u6642\u975e\u5e38\u6709\u7528\uff0c\u4f8b\u5982\u5728\u8cc7\u6599\u5eab\u4e2d\u9032\u884c\u6279\u91cf\u66f4\u65b0\u6216\u63d2\u5165\u64cd\u4f5c\u3002<\/p>\n<h2 id=\"while-%e5%be%aa%e7%92%b0%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-PFhXZqdyDj\">while \u5faa\u74b0\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<pre><code>\nWHILE (\u689d\u4ef6)\nBEGIN\n    -- \u57f7\u884c\u7684 SQL \u8a9e\u53e5\nEND\n<\/code><\/pre>\n<p>\u5728\u9019\u6bb5\u8a9e\u6cd5\u4e2d\uff0c\u7576\u689d\u4ef6\u70ba\u771f\u6642\uff0cBEGIN \u548c END \u4e4b\u9593\u7684 SQL \u8a9e\u53e5\u5c07\u88ab\u91cd\u8907\u57f7\u884c\u3002\u7576\u689d\u4ef6\u8b8a\u70ba\u5047\u6642\uff0c\u5faa\u74b0\u5c07\u7d42\u6b62\u3002<\/p>\n<h2 id=\"while-%e5%be%aa%e7%92%b0%e7%9a%84%e6%87%89%e7%94%a8%e7%af%84%e4%be%8b-PFhXZqdyDj\">while \u5faa\u74b0\u7684\u61c9\u7528\u7bc4\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528 while \u5faa\u74b0\u7684\u7bc4\u4f8b\uff0c\u8a72\u7bc4\u4f8b\u5c07\u5f9e\u4e00\u500b\u8868\u4e2d\u9010\u884c\u8b80\u53d6\u8cc7\u6599\u4e26\u9032\u884c\u8655\u7406\uff1a<\/p>\n<pre><code>\nDECLARE @Counter INT = 1;\nDECLARE @MaxCounter INT;\n\nSELECT @MaxCounter = COUNT(*) FROM YourTable;\n\nWHILE @Counter &lt;= @MaxCounter\nBEGIN\n    -- \u9019\u88e1\u53ef\u4ee5\u57f7\u884c\u4e00\u4e9b\u64cd\u4f5c\uff0c\u4f8b\u5982\u66f4\u65b0\u6216\u63d2\u5165\u8cc7\u6599\n    PRINT &#039;Processing row number: &#039; + CAST(@Counter AS VARCHAR);\n\n    -- \u589e\u52a0\u8a08\u6578\u5668\n    SET @Counter = @Counter + 1;\nEND\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u9996\u5148\u5ba3\u544a\u4e86\u4e00\u500b\u8a08\u6578\u5668 @Counter\uff0c\u4e26\u5c07\u5176\u521d\u59cb\u5316\u70ba 1\u3002\u63a5\u8457\uff0c\u6211\u5011\u67e5\u8a62 YourTable \u8868\u4e2d\u7684\u7e3d\u884c\u6578\uff0c\u4e26\u5c07\u5176\u8ce6\u503c\u7d66 @MaxCounter\u3002while \u5faa\u74b0\u5c07\u5728 @Counter \u5c0f\u65bc\u6216\u7b49\u65bc @MaxCounter \u7684\u60c5\u6cc1\u4e0b\u57f7\u884c\uff0c\u4e26\u5728\u6bcf\u6b21\u8ff4\u5708\u4e2d\u6253\u5370\u7576\u524d\u8655\u7406\u7684\u884c\u865f\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-PFhXZqdyDj\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<ul>\n<li>\u78ba\u4fdd\u5faa\u74b0\u689d\u4ef6\u6700\u7d42\u6703\u8b8a\u70ba\u5047\uff0c\u4ee5\u907f\u514d\u7121\u9650\u5faa\u74b0\u7684\u60c5\u6cc1\u3002<\/li>\n<li>\u5728\u5faa\u74b0\u5167\u90e8\u9032\u884c\u7684\u64cd\u4f5c\u61c9\u8a72\u662f\u9ad8\u6548\u7684\uff0c\u4ee5\u6e1b\u5c11\u5c0d\u8cc7\u6599\u5eab\u6027\u80fd\u7684\u5f71\u97ff\u3002<\/li>\n<li>\u8003\u616e\u4f7f\u7528\u5176\u4ed6\u63a7\u5236\u7d50\u69cb\uff08\u5982 cursor\uff09\u4f86\u8655\u7406\u5927\u91cf\u8cc7\u6599\u6642\uff0c\u53ef\u80fd\u6703\u66f4\u6709\u6548\u7387\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-PFhXZqdyDj\">\u7d50\u8ad6<\/h2>\n<p>while \u5faa\u74b0\u5728 SQL \u4e2d\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5728\u6eff\u8db3\u7279\u5b9a\u689d\u4ef6\u7684\u60c5\u6cc1\u4e0b\u91cd\u8907\u57f7\u884c\u64cd\u4f5c\u3002\u900f\u904e\u9069\u7576\u7684\u4f7f\u7528\uff0cwhile \u5faa\u74b0\u53ef\u4ee5\u63d0\u9ad8\u8cc7\u6599\u8655\u7406\u7684\u6548\u7387\uff0c\u4e26\u7c21\u5316\u8907\u96dc\u7684\u908f\u8f2f\u3002\u5c0d\u65bc\u9700\u8981\u9032\u884c\u6279\u91cf\u64cd\u4f5c\u7684\u60c5\u6cc1\uff0cwhile \u5faa\u74b0\u63d0\u4f9b\u4e86\u4e00\u7a2e\u9748\u6d3b\u7684\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u9069\u5408\u5404\u7a2e\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3 SQL \u4e2d\u7684 WHILE \u5faa\u74b0\u57f7\u884c\u63a7\u5236\uff0c\u5b78\u7fd2\u5982\u4f55\u6709\u6548\u5730\u91cd\u8907\u57f7\u884c\u67e5\u8a62\u4ee5\u8655\u7406\u6578\u64da\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-168415","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168415","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=168415"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168415\/revisions"}],"predecessor-version":[{"id":168416,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168415\/revisions\/168416"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}