{"id":78838,"date":"2024-10-16T12:21:17","date_gmt":"2024-10-16T04:21:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/78838\/"},"modified":"2024-10-16T12:21:17","modified_gmt":"2024-10-16T04:21:17","slug":"mysql%e6%8c%87%e4%bb%a4-iterate%ef%bc%88%e8%bf%ad%e4%bb%a3%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/78838\/","title":{"rendered":"MySQL\u6307\u4ee4: ITERATE\uff08\u8fed\u4ee3\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-iterate%ef%bc%88%e8%bf%ad%e4%bb%a3%ef%bc%89-zXVRpAyHkB\">MySQL\u6307\u4ee4: ITERATE\uff08\u8fed\u4ee3\uff09<\/h1>\n<p>\u5728MySQL\u4e2d\uff0c\u8fed\u4ee3\uff08ITERATE\uff09\u662f\u4e00\u500b\u91cd\u8981\u7684\u63a7\u5236\u6d41\u8a9e\u53e5\uff0c\u901a\u5e38\u7528\u65bc\u5b58\u5132\u904e\u7a0b\u4e2d\u3002\u5b83\u7684\u4e3b\u8981\u529f\u80fd\u662f\u8b93\u7a0b\u5e8f\u5728\u7279\u5b9a\u689d\u4ef6\u4e0b\u91cd\u8907\u57f7\u884c\u67d0\u6bb5\u4ee3\u78bc\uff0c\u9019\u5c0d\u65bc\u9700\u8981\u91cd\u8907\u8655\u7406\u6578\u64da\u7684\u60c5\u6cc1\u7279\u5225\u6709\u7528\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eITERATE\u7684\u7528\u6cd5\u3001\u8a9e\u6cd5\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u793a\u4f8b\u3002<\/p>\n<h2 id=\"iterate%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-zXVRpAyHkB\">ITERATE\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>ITERATE\u8a9e\u53e5\u901a\u5e38\u8207LOOP\u8a9e\u53e5\u4e00\u8d77\u4f7f\u7528\uff0c\u5f62\u6210\u4e00\u500b\u5faa\u74b0\u7d50\u69cb\u3002\u7576\u6eff\u8db3\u7279\u5b9a\u689d\u4ef6\u6642\uff0cITERATE\u6703\u8df3\u904e\u7576\u524d\u5faa\u74b0\u7684\u5269\u9918\u90e8\u5206\uff0c\u4e26\u91cd\u65b0\u958b\u59cb\u4e0b\u4e00\u6b21\u5faa\u74b0\u3002\u9019\u4f7f\u5f97\u958b\u767c\u8005\u80fd\u5920\u9748\u6d3b\u5730\u63a7\u5236\u5faa\u74b0\u7684\u57f7\u884c\u6d41\u7a0b\u3002<\/p>\n<h2 id=\"iterate%e7%9a%84%e8%aa%9e%e6%b3%95-zXVRpAyHkB\">ITERATE\u7684\u8a9e\u6cd5<\/h2>\n<pre><code>\nDECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;\n\nLOOP\n    -- \u4f60\u7684\u4ee3\u78bc\u908f\u8f2f\n    IF  THEN\n        ITERATE ;\n    END IF;\n    -- \u5176\u4ed6\u4ee3\u78bc\nEND LOOP ;\n<\/code><\/pre>\n<p>\u5728\u4e0a\u8ff0\u8a9e\u6cd5\u4e2d\uff0c<code>loop_label<\/code>\u662f\u53ef\u9078\u7684\u6a19\u7c64\uff0c\u7528\u65bc\u6a19\u8b58\u5faa\u74b0\u3002\u7576\u6eff\u8db3<code>IF<\/code>\u689d\u4ef6\u6642\uff0c\u7a0b\u5e8f\u5c07\u8df3\u904e\u7576\u524d\u5faa\u74b0\u7684\u5269\u9918\u90e8\u5206\uff0c\u4e26\u91cd\u65b0\u958b\u59cb\u4e0b\u4e00\u6b21\u5faa\u74b0\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%a4%ba%e4%be%8b-zXVRpAyHkB\">\u4f7f\u7528\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528ITERATE\u7684\u7c21\u55ae\u793a\u4f8b\uff0c\u8a72\u793a\u4f8b\u5c55\u793a\u4e86\u5982\u4f55\u5728\u5b58\u5132\u904e\u7a0b\u4e2d\u4f7f\u7528ITERATE\u4f86\u8655\u7406\u6578\u64da\uff1a<\/p>\n<pre><code>\nDELIMITER \/\/\n\nCREATE PROCEDURE iterate_example()\nBEGIN\n    DECLARE done INT DEFAULT FALSE;\n    DECLARE counter INT DEFAULT 0;\n\n    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;\n\n    my_loop: LOOP\n        SET counter = counter + 1;\n\n        IF counter = 5 THEN\n            ITERATE my_loop; -- \u7576counter\u7b49\u65bc5\u6642\uff0c\u8df3\u904e\u5269\u9918\u4ee3\u78bc\n        END IF;\n\n        SELECT counter; -- \u8f38\u51facounter\u7684\u503c\n\n        IF done THEN\n            LEAVE my_loop; -- \u7576done\u70baTRUE\u6642\uff0c\u9000\u51fa\u5faa\u74b0\n        END IF;\n    END LOOP my_loop;\n\nEND \/\/\n\nDELIMITER ;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u7576\u8a08\u6578\u5668\u9054\u52305\u6642\uff0c\u7a0b\u5e8f\u5c07\u8df3\u904e\u8f38\u51fa\u8a08\u6578\u5668\u7684\u503c\uff0c\u4e26\u91cd\u65b0\u958b\u59cb\u5faa\u74b0\u3002\u9019\u6a23\u7684\u8a2d\u8a08\u53ef\u4ee5\u907f\u514d\u5728\u7279\u5b9a\u689d\u4ef6\u4e0b\u57f7\u884c\u4e0d\u5fc5\u8981\u7684\u64cd\u4f5c\u3002<\/p>\n<h2 id=\"iterate%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-zXVRpAyHkB\">ITERATE\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>ITERATE\u5728\u8a31\u591a\u5834\u666f\u4e2d\u90fd\u975e\u5e38\u6709\u7528\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u5c0d\u6578\u64da\u9032\u884c\u591a\u6b21\u8655\u7406\u7684\u60c5\u6cc1\u4e0b\u3002\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u6e05\u7406\uff1a<\/strong>\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\uff0c\u53ef\u80fd\u9700\u8981\u8df3\u904e\u67d0\u4e9b\u4e0d\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\u3002<\/li>\n<li><strong>\u8a08\u7b97\u7d71\u8a08\uff1a<\/strong>\u5728\u8a08\u7b97\u7d71\u8a08\u6578\u64da\u6642\uff0c\u53ef\u80fd\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u4f86\u6c7a\u5b9a\u662f\u5426\u7e7c\u7e8c\u8a08\u7b97\u3002<\/li>\n<li><strong>\u6279\u91cf\u8655\u7406\uff1a<\/strong>\u5728\u6279\u91cf\u8655\u7406\u6578\u64da\u6642\uff0c\u53ef\u80fd\u9700\u8981\u6839\u64da\u67d0\u4e9b\u689d\u4ef6\u4f86\u6c7a\u5b9a\u662f\u5426\u8df3\u904e\u67d0\u4e9b\u8a18\u9304\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-zXVRpAyHkB\">\u7e3d\u7d50<\/h2>\n<p>MySQL\u4e2d\u7684ITERATE\u8a9e\u53e5\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5728\u5b58\u5132\u904e\u7a0b\u4e2d\u9748\u6d3b\u5730\u63a7\u5236\u5faa\u74b0\u7684\u57f7\u884c\u6d41\u7a0b\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528ITERATE\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\uff0c\u4e26\u7c21\u5316\u4ee3\u78bc\u908f\u8f2f\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\u5834\u666f\uff0c\u9078\u64c7\u5408\u9069\u7684<code>VPS<\/code>\u89e3\u6c7a\u65b9\u6848\uff0c\u5982<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\uff0c\u53ef\u4ee5\u9032\u4e00\u6b65\u63d0\u5347\u6027\u80fd\u548c\u7a69\u5b9a\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u6307\u4ee4ITERATE\uff08\u8fed\u4ee3\uff09\uff0c\u638c\u63e1\u5982\u4f55\u5728\u5b58\u50a8\u8fc7\u7a0b\u4e2d\u63a7\u5236\u5faa\u73af\uff0c\u63d0\u5347\u6570\u636e\u5e93\u64cd\u4f5c\u6548\u7387\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-78838","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78838","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=78838"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78838\/revisions"}],"predecessor-version":[{"id":78839,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78838\/revisions\/78839"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=78838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=78838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=78838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}