{"id":20646,"date":"2024-01-02T05:16:24","date_gmt":"2024-01-02T05:16:24","guid":{"rendered":"https:\/\/server.hk\/blog\/20646\/"},"modified":"2024-11-14T10:39:24","modified_gmt":"2024-11-14T02:39:24","slug":"postgresql-command-listen","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/20646\/","title":{"rendered":"PostgreSQL \u547d\u4ee4: LISTEN"},"content":{"rendered":"

PostgreSQL \u547d\u4ee4: LISTEN<\/h1>\n

PostgreSQL \u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u806f\u5f0f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u591a\u7a2e\u529f\u80fd\u548c\u64cd\u4f5c\u9078\u9805\u3002\u5176\u4e2d\u4e00\u500b\u91cd\u8981\u7684\u547d\u4ee4\u662f LISTEN<\/code>\u3002\u672c\u6587\u5c07\u63a2\u8a0e LISTEN<\/code> \u547d\u4ee4\u7684\u4f5c\u7528\u4ee5\u53ca\u5982\u4f55\u5728 PostgreSQL \u4e2d\u4f7f\u7528\u5b83\u3002<\/p>\n

\u4e86\u89e3 LISTEN \u547d\u4ee4<\/h2>\n

PostgreSQL \u4e2d\u7684 LISTEN<\/code> \u547d\u4ee4\u7528\u65bc\u8a02\u95b1\u7279\u5b9a\u7684\u901a\u77e5\u983b\u9053\u3002\u5b83\u5141\u8a31\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u5728\u67d0\u4e9b\u4e8b\u4ef6\u767c\u751f\u6642\uff0c\u5f9e\u6578\u64da\u5eab\u4f3a\u670d\u5668\u63a5\u6536\u901a\u77e5\u3002\u9019\u4e9b\u4e8b\u4ef6\u53ef\u4ee5\u5305\u62ec\u6578\u64da\u5eab\u7684\u66f4\u6539\u3001\u7279\u5b9a\u8868\u683c\u7684\u66f4\u65b0\uff0c\u6216\u662f\u61c9\u7528\u7a0b\u5f0f\u81ea\u5b9a\u7fa9\u7684\u5176\u4ed6\u4e8b\u4ef6\u3002<\/p>\n

\u7576\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u57f7\u884c LISTEN<\/code> \u547d\u4ee4\u6642\uff0c\u5b83\u6703\u7b49\u5f85\u6307\u5b9a\u983b\u9053\u4e0a\u7684\u901a\u77e5\u3002\u4e00\u65e6\u63a5\u6536\u5230\u901a\u77e5\uff0c\u61c9\u7528\u7a0b\u5f0f\u53ef\u4ee5\u6839\u64da\u8a72\u4e8b\u4ef6\u57f7\u884c\u4efb\u4f55\u5fc5\u8981\u7684\u64cd\u4f5c\u3002<\/p>\n

\u4f7f\u7528 LISTEN \u547d\u4ee4<\/h2>\n

\u4f7f\u7528 LISTEN<\/code> \u547d\u4ee4\u6642\uff0c\u4f60\u9700\u8981\u9075\u5faa\u4ee5\u4e0b\u6b65\u9a5f\uff1a<\/p>\n

    \n
  1. \u5275\u5efa\u4e00\u500b\u901a\u77e5\u983b\u9053\uff1a\u5728\u8a02\u95b1\u901a\u77e5\u4e4b\u524d\uff0c\u4f60\u9700\u8981\u5275\u5efa\u4e00\u500b\u901a\u77e5\u983b\u9053\u3002\u9019\u53ef\u4ee5\u901a\u904e CREATE CHANNEL<\/code> \u547d\u4ee4\u4f86\u5b8c\u6210\u3002\u4f8b\u5982\uff1aCREATE CHANNEL my_channel;<\/code><\/li>\n
  2. \u8a02\u95b1\u983b\u9053\uff1a\u5275\u5efa\u983b\u9053\u5f8c\uff0c\u53ef\u4ee5\u4f7f\u7528 LISTEN<\/code> \u547d\u4ee4\u8a02\u95b1\u5b83\u3002\u4f8b\u5982\uff1aLISTEN my_channel;<\/code><\/li>\n
  3. \u7b49\u5f85\u901a\u77e5\uff1a\u8a02\u95b1\u983b\u9053\u5f8c\uff0c\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u53ef\u4ee5\u4f7f\u7528 WAIT<\/code> \u547d\u4ee4\u7b49\u5f85\u901a\u77e5\u3002\u4f8b\u5982\uff1aWAIT;<\/code><\/li>\n
  4. \u8655\u7406\u901a\u77e5\uff1a\u7576\u63a5\u6536\u5230\u901a\u77e5\u6642\uff0c\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u53ef\u4ee5\u57f7\u884c\u5fc5\u8981\u7684\u64cd\u4f5c\u3002\u9019\u53ef\u4ee5\u5305\u62ec\u66f4\u65b0\u7528\u6236\u754c\u9762\u3001\u89f8\u767c\u5176\u4ed6\u9032\u7a0b\u6216\u8a18\u9304\u8a72\u4e8b\u4ef6\u3002<\/li>\n<\/ol>\n

    \u503c\u5f97\u6ce8\u610f\u7684\u662f\uff0cLISTEN<\/code> \u547d\u4ee4\u901a\u5e38\u8207 NOTIFY<\/code> \u547d\u4ee4\u7d50\u5408\u4f7f\u7528\u3002NOTIFY<\/code> \u547d\u4ee4\u7528\u65bc\u5411\u8a02\u95b1\u7684\u983b\u9053\u767c\u9001\u901a\u77e5\u3002\u7576\u9700\u8981\u89f8\u767c\u901a\u77e5\u7684\u4e8b\u4ef6\u767c\u751f\u6642\uff0c\u6703\u57f7\u884c\u5e36\u6709\u76f8\u61c9\u983b\u9053\u540d\u7a31\u548c\u6709\u6548\u8ca0\u8f09\u7684 NOTIFY<\/code> \u547d\u4ee4\u3002<\/p>\n

    \u7bc4\u4f8b\u4f7f\u7528<\/h2>\n

    \u8b93\u6211\u5011\u4f86\u770b\u4e00\u500b\u7bc4\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u5b58\u5132\u5ba2\u6236\u8cc7\u8a0a\u7684 PostgreSQL \u6578\u64da\u5eab\u3002\u6211\u5011\u5e0c\u671b\u6bcf\u7576\u6709\u65b0\u5ba2\u6236\u6dfb\u52a0\u5230\u6578\u64da\u5eab\u6642\uff0c\u901a\u77e5\u6211\u5011\u7684\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u3002\u4ee5\u4e0b\u662f\u6211\u5011\u5982\u4f55\u4f7f\u7528 LISTEN<\/code> \u547d\u4ee4\u4f86\u5be6\u73fe\u6b64\u76ee\u6a19\uff1a<\/p>\n

    CREATE CHANNEL customer_channel;\r\nLISTEN customer_channel;\r\nWAIT;\r\n<\/code><\/pre>\n
    \u5728\u6211\u5011\u7684\u61c9\u7528\u7a0b\u5f0f\u4ee3\u78bc\u4e2d\uff0c\u53ef\u4ee5\u8a2d\u7f6e\u4e00\u500b\u76e3\u807d\u5668\u7b49\u5f85 customer_channel<\/code> \u983b\u9053\u4e0a\u7684\u901a\u77e5\u3002\u7576\u65b0\u5ba2\u6236\u88ab\u6dfb\u52a0\u5230\u6578\u64da\u5eab\u6642\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 NOTIFY<\/code> \u547d\u4ee4\u5411 customer_channel<\/code> \u767c\u9001\u901a\u77e5\u3002\u76e3\u807d\u5668\u63a5\u6536\u5230\u901a\u77e5\u5f8c\uff0c\u5c07\u57f7\u884c\u5fc5\u8981\u7684\u64cd\u4f5c\u3002<\/p>\n
    \u7d50\u8ad6<\/h2>\n
    PostgreSQL \u4e2d\u7684 LISTEN<\/code> \u547d\u4ee4\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u9069\u7528\u65bc\u69cb\u5efa\u9700\u8981\u4e8b\u4ef6\u9a45\u52d5\u529f\u80fd\u7684\u5be6\u6642\u61c9\u7528\u7a0b\u5f0f\u3002\u901a\u904e\u8a02\u95b1\u7279\u5b9a\u7684\u901a\u77e5\u983b\u9053\uff0c\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u53ef\u4ee5\u5f9e\u6578\u64da\u5eab\u4f3a\u670d\u5668\u63a5\u6536\u901a\u77e5\u4e26\u4f5c\u51fa\u76f8\u61c9\u7684\u56de\u61c9\u3002\u7406\u89e3\u5982\u4f55\u4f7f\u7528 LISTEN<\/code> \u547d\u4ee4\uff0c\u70ba\u5275\u5efa\u52d5\u614b\u548c\u97ff\u61c9\u5f0f\u61c9\u7528\u7a0b\u5f0f\u63d0\u4f9b\u4e86\u66f4\u591a\u53ef\u80fd\u6027\u3002<\/p>\n
    \u7e3d\u7d50<\/h2>\n
    \u7e3d\u7d50\u4f86\u8aaa\uff0cPostgreSQL \u4e2d\u7684 LISTEN<\/code> \u547d\u4ee4\u5141\u8a31\u5ba2\u6236\u7aef\u61c9\u7528\u7a0b\u5f0f\u8a02\u95b1\u7279\u5b9a\u7684\u901a\u77e5\u983b\u9053\uff0c\u4e26\u5728\u4e8b\u4ef6\u767c\u751f\u6642\u63a5\u6536\u901a\u77e5\u3002\u901a\u904e\u5c07 LISTEN<\/code> \u547d\u4ee4\u8207 NOTIFY<\/code> \u547d\u4ee4\u7d50\u5408\u4f7f\u7528\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u69cb\u5efa\u5be6\u6642\u97ff\u61c9\u6578\u64da\u5eab\u8b8a\u66f4\u7684\u61c9\u7528\u7a0b\u5f0f\u3002\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc PostgreSQL \u53ca\u5176\u529f\u80fd\u7684\u8cc7\u8a0a\uff0c\u8acb\u8003\u616e\u63a2\u7d22 Server.HK<\/a>\uff0c\u9019\u662f\u4e00\u5bb6\u9818\u5148\u7684 VPS \u8a17\u7ba1\u63d0\u4f9b\u5546\uff0c\u63d0\u4f9b\u53ef\u9760\u4e14\u53ef\u64f4\u5c55\u7684\u8a17\u7ba1\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
    PostgreSQL \u547d\u4ee4: L...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4924],"tags":[],"class_list":["post-20646","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20646","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=20646"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20646\/revisions"}],"predecessor-version":[{"id":24366,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20646\/revisions\/24366"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=20646"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=20646"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=20646"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}