{"id":78846,"date":"2024-10-16T12:25:13","date_gmt":"2024-10-16T04:25:13","guid":{"rendered":"https:\/\/server.hk\/cnblog\/78846\/"},"modified":"2024-10-16T12:25:13","modified_gmt":"2024-10-16T04:25:13","slug":"mysql%e6%8c%87%e4%bb%a4-leave%ef%bc%88%e9%9b%a2%e9%96%8b%e5%be%aa%e7%92%b0%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/78846\/","title":{"rendered":"MySQL\u6307\u4ee4: LEAVE\uff08\u96e2\u958b\u5faa\u74b0\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-leave%ef%bc%88%e9%9b%a2%e9%96%8b%e5%be%aa%e7%92%b0%ef%bc%89-QxAhModkNa\">MySQL\u6307\u4ee4: LEAVE\uff08\u96e2\u958b\u5faa\u74b0\uff09<\/h1>\n<p>\u5728MySQL\u4e2d\uff0cLEAVE\u6307\u4ee4\u662f\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u63a7\u5236\u6d41\u8a9e\u53e5\uff0c\u4e3b\u8981\u7528\u65bc\u5f9e\u5faa\u74b0\u7d50\u69cb\u4e2d\u63d0\u524d\u9000\u51fa\u3002\u9019\u5728\u8655\u7406\u8907\u96dc\u7684\u67e5\u8a62\u6216\u6578\u64da\u8655\u7406\u6642\uff0c\u80fd\u5920\u63d0\u9ad8\u6548\u7387\u4e26\u7c21\u5316\u4ee3\u78bc\u7d50\u69cb\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eLEAVE\u6307\u4ee4\u7684\u7528\u6cd5\u3001\u8a9e\u6cd5\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u793a\u4f8b\u3002<\/p>\n<h2 id=\"leave%e6%8c%87%e4%bb%a4%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-QxAhModkNa\">LEAVE\u6307\u4ee4\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>LEAVE\u6307\u4ee4\u901a\u5e38\u8207LOOP\u3001WHILE\u6216REPEAT\u5faa\u74b0\u7d50\u69cb\u4e00\u8d77\u4f7f\u7528\u3002\u7576\u57f7\u884c\u5230LEAVE\u6307\u4ee4\u6642\uff0c\u7a0b\u5e8f\u6703\u7acb\u5373\u8df3\u51fa\u7576\u524d\u7684\u5faa\u74b0\uff0c\u4e26\u7e7c\u7e8c\u57f7\u884c\u5faa\u74b0\u5f8c\u7684\u4ee3\u78bc\u3002\u9019\u5c0d\u65bc\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u63d0\u524d\u7d42\u6b62\u5faa\u74b0\u7684\u60c5\u6cc1\u7279\u5225\u6709\u7528\u3002<\/p>\n<h2 id=\"leave%e7%9a%84%e8%aa%9e%e6%b3%95-QxAhModkNa\">LEAVE\u7684\u8a9e\u6cd5<\/h2>\n<pre><code>\nLEAVE <label>;\n<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>label_name<\/code>\u662f\u5faa\u74b0\u7684\u6a19\u7c64\u540d\u7a31\u3002\u6a19\u7c64\u662f\u53ef\u9078\u7684\uff0c\u4f46\u5728\u591a\u5c64\u5faa\u74b0\u4e2d\u4f7f\u7528\u6a19\u7c64\u53ef\u4ee5\u5e6b\u52a9\u660e\u78ba\u6307\u5b9a\u8981\u9000\u51fa\u7684\u5faa\u74b0\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%a4%ba%e4%be%8b-QxAhModkNa\">\u4f7f\u7528\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528LEAVE\u6307\u4ee4\u7684\u7c21\u55ae\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5728WHILE\u5faa\u74b0\u4e2d\u4f7f\u7528\u5b83\uff1a<\/p>\n<pre><code>\nDELIMITER \/\/\n\nCREATE PROCEDURE example_procedure()\nBEGIN\n    DECLARE counter INT DEFAULT 0;\n\n    WHILE counter &lt; 10 DO\n        SET counter = counter + 1;\n\n        IF counter = 5 THEN\n            LEAVE;\n        END IF;\n\n        SELECT counter;\n    END WHILE;\nEND \/\/\n\nDELIMITER ;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u7576\u8a08\u6578\u5668\u9054\u52305\u6642\uff0cLEAVE\u6307\u4ee4\u6703\u88ab\u89f8\u767c\uff0c\u5f9e\u800c\u63d0\u524d\u9000\u51fa\u5faa\u74b0\u3002\u9019\u6a23\u7684\u8a2d\u8a08\u53ef\u4ee5\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u8a08\u7b97\uff0c\u63d0\u5347\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e5%a4%9a%e5%b1%a4%e5%be%aa%e7%92%b0%e4%b8%ad%e7%9a%84leave-QxAhModkNa\">\u591a\u5c64\u5faa\u74b0\u4e2d\u7684LEAVE<\/h2>\n<p>\u5728\u591a\u5c64\u5faa\u74b0\u4e2d\uff0cLEAVE\u6307\u4ee4\u53ef\u4ee5\u8207\u6a19\u7c64\u4e00\u8d77\u4f7f\u7528\uff0c\u4ee5\u4fbf\u7cbe\u78ba\u63a7\u5236\u8981\u9000\u51fa\u7684\u5faa\u74b0\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>\nDELIMITER \/\/\n\nCREATE PROCEDURE nested_example()\nBEGIN\n    DECLARE outer_counter INT DEFAULT 0;\n    DECLARE inner_counter INT DEFAULT 0;\n\n    outer_loop: WHILE outer_counter &lt; 3 DO\n        SET outer_counter = outer_counter + 1;\n        inner_counter = 0;\n\n        inner_loop: WHILE inner_counter &lt; 5 DO\n            SET inner_counter = inner_counter + 1;\n\n            IF inner_counter = 3 THEN\n                LEAVE outer_loop;\n            END IF;\n\n            SELECT CONCAT(&#039;Outer: &#039;, outer_counter, &#039; Inner: &#039;, inner_counter);\n        END WHILE;\n    END WHILE;\nEND \/\/\n\nDELIMITER ;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u7576\u5167\u90e8\u8a08\u6578\u5668\u9054\u52303\u6642\uff0cLEAVE\u6307\u4ee4\u6703\u4f7f\u7a0b\u5e8f\u8df3\u51fa\u5916\u90e8\u5faa\u74b0\uff0c\u5f9e\u800c\u7d50\u675f\u6574\u500b\u904e\u7a0b\u3002<\/p>\n<h2 id=\"leave%e7%9a%84%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-QxAhModkNa\">LEAVE\u7684\u6ce8\u610f\u4e8b\u9805<\/h2>\n<ul>\n<li>LEAVE\u6307\u4ee4\u53ea\u80fd\u7528\u65bc\u5faa\u74b0\u7d50\u69cb\u4e2d\uff0c\u4e0d\u80fd\u55ae\u7368\u4f7f\u7528\u3002<\/li>\n<li>\u5728\u4f7f\u7528\u591a\u5c64\u5faa\u74b0\u6642\uff0c\u5efa\u8b70\u4f7f\u7528\u6a19\u7c64\u4f86\u660e\u78ba\u6307\u5b9a\u8981\u9000\u51fa\u7684\u5faa\u74b0\u3002<\/li>\n<li>\u904e\u5ea6\u4f7f\u7528LEAVE\u53ef\u80fd\u6703\u4f7f\u4ee3\u78bc\u8b8a\u5f97\u96e3\u4ee5\u7406\u89e3\uff0c\u56e0\u6b64\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-QxAhModkNa\">\u7e3d\u7d50<\/h2>\n<p>LEAVE\u6307\u4ee4\u5728MySQL\u4e2d\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u6709\u6548\u5730\u63a7\u5236\u5faa\u74b0\u7d50\u69cb\u7684\u57f7\u884c\u6d41\u7a0b\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528LEAVE\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u78bc\u7684\u53ef\u8b80\u6027\u548c\u57f7\u884c\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\u5834\u666f\uff0c\u638c\u63e1LEAVE\u6307\u4ee4\u7684\u4f7f\u7528\u5c07\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bcVPS\u6216\u5176\u4ed6\u4f3a\u670d\u5668\u89e3\u6c7a\u65b9\u6848\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4e86\u89e3\u66f4\u591a\u8cc7\u8a0a\uff0c\u63a2\u7d22\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u53ca\u5176\u4ed6\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u6307\u4ee4LEAVE\uff0c\u5982\u4f55\u5728\u5b58\u5132\u904e\u7a0b\u6216\u5faa\u74b0\u4e2d\u5b89\u5168\u5730\u9000\u51fa\uff0c\u63d0\u5347\u6578\u64da\u5eab\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-78846","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78846","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=78846"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78846\/revisions"}],"predecessor-version":[{"id":78847,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78846\/revisions\/78847"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=78846"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=78846"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=78846"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}