{"id":1696,"date":"2015-01-06T18:24:49","date_gmt":"2015-01-06T10:24:49","guid":{"rendered":"http:\/\/blog.qdac.cc\/?p=1696"},"modified":"2015-01-06T18:24:49","modified_gmt":"2015-01-06T10:24:49","slug":"postgresql-%e6%9c%8d%e5%8a%a1%e5%99%a8%e7%ab%af%e9%80%9a%e7%9f%a5","status":"publish","type":"post","link":"https:\/\/blog.qdac.cc\/?p=1696","title":{"rendered":"[PostgreSQL] &#8211; \u670d\u52a1\u5668\u7aef\u901a\u77e5"},"content":{"rendered":"<p>PostgreSQL \u652f\u6301\u4ece\u670d\u52a1\u5668\u7aef\u5411\u5ba2\u6237\u7aef\u4e3b\u52a8\u63a8\u9001\u901a\u77e5\u4fe1\u606f\uff0c\u524d\u63d0\u662f\u5ba2\u6237\u7aef\u76d1\u542c\u6307\u5b9a\u540d\u79f0\u7684\u901a\u77e5\u3002\u8fd9\u6837\u505a\u7684\u597d\u5904\u662f\u5ba2\u6237\u7aef\u53ef\u4ee5\u76d1\u6d4b\u670d\u52a1\u5668\u7aef\u7684\u6570\u636e\u6539\u53d8\uff0c\u4ee5\u4fbf\u66f4\u65b0\u672c\u5730\u7684\u6570\u636e\u7b49\u884c\u4e3a\uff0c\u5c24\u5176\u662f\u9002\u5408\u5b57\u5178\u7c7b\u578b\u7684\u6570\u636e\u53ca\u65f6\u66f4\u65b0\u3002<\/p>\n<p>\u9996\u5148\uff0c\u5ba2\u6237\u7aef\u4f7f\u7528 Listen \u6307\u4ee4\u6765\u901a\u77e5\u670d\u52a1\u5668\u81ea\u5df1\u8981\u76d1\u542c\u7684\u901a\u77e5\u7684\u540d\u79f0\u3002\u7136\u540e\u4e00\u65e6\u6709\u4eba\u89e6\u53d1\u4e86\u8fd9\u4e2a\u901a\u77e5\uff08\u5982\u679c\u89e6\u53d1\u662f\u5728\u4e8b\u52a1\u4e2d\uff0c\u5219\u4e8b\u52a1\u5b8c\u6210\u540e\u5b9e\u9645\u901a\u77e5\uff09\uff0c\u5ba2\u6237\u7aef\u5c31\u4f1a\u6536\u5230\u76f8\u5e94\u7684\u901a\u77e5\u4fe1\u606f\u3002\u6bd4\u5982\u5148\u6267\u884c\u4e0b\u9762\u7684\u811a\u672c\u76d1\u542c DictionaryChanged \u901a\u77e5\uff1a<\/p>\n<pre class=\"lang:pgsql decode:true\">listen DictionaryChanged;<\/pre>\n<p>\u7136\u540e\u5728\u5176\u5b83\u5730\u65b9\u89e6\u53d1\u8be5\u901a\u77e5\uff1a<\/p>\n<pre class=\"lang:delphi decode:true \">notify DictionaryChanged,'{\"table\":\"dict_cities\",\"action\":\"insert\",\"rowid\":8788}';<\/pre>\n<p>\u5728\u6211\u4eec\u7684\u5ba2\u6237\u7aef\u5c31\u4f1a\u6536\u5230\u8be5\u901a\u77e5\uff1a<\/p>\n<pre class=\"lang:pgsql decode:true \">'dictionarychanged'\u7684\u5f02\u6b65\u901a\u77e5\u5df2\u4ece\u540e\u53f0\u8fdb\u7a0b pid 29738  \u6536\u5230\u3002\r\n   \u6570\u636e: {\"table\":\"dict_cities\",\"action\":\"insert\",\"rowid\":8788}\r\n<\/pre>\n<p>\u8fd9\u91cc\u6ce8\u610f\u4e00\u70b9\uff0c\u901a\u77e5\u7684\u9644\u52a0\u7684\u5b57\u7b26\u4e32\u6570\u636e\u957f\u5ea6\u6700\u5927\u4e3a8KB\uff0c\u4f46\u5b83\u7684\u503c\u53ef\u4ee5\u5728\u914d\u7f6e\u6587\u4ef6\u4e2d\u4fee\u6539\u3002\u4e2a\u4eba\u63a8\u8350\u7ed3\u5408QJSON\u4f7f\u7528JSON\u683c\u5f0f\u6765\u4f20\u9001\u901a\u77e5\u53c2\u6570\uff0c\u4ee5\u65b9\u4fbf\u89e3\u6790\u548c\u5904\u7406\u3002<\/p>\n<p>\u5728\u4e0d\u518d\u5173\u5fc3\u8be5\u901a\u77e5\u65f6\uff0c\u53ea\u9700\u8981\u7528\u00a0Unlisten \u6307\u4ee4\u79fb\u9664\u76d1\u542c\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n<pre class=\"lang:delphi decode:true \">unlisten DictionaryNotify;<\/pre>\n<p>\u662f\u4e0d\u662f\u611f\u89c9\u5f88\u65b9\u4fbf:)<\/p>\n<p>\u597d\u4e86\uff0c\u5207\u6362\u5230 QDAC \u4e2d QDB \u5355\u5143\uff0cTQProvider \u5c06\u63d0\u4f9b\u8fd9\u4e48\u4e00\u7ec4\u63a5\u53e3\uff0c\u6765\u9690\u85cf\u670d\u52a1\u5668\u7aef\u7684\u8fd9\u4e9b\u4e1c\u897f\u3002<\/p>\n<pre class=\"lang:delphi decode:true \">\/\/\/ &lt;summary&gt;\u76d1\u542c\u670d\u52a1\u5668\u4e0a\u6307\u5b9a\u540d\u79f0\u7684\u901a\u77e5&lt;\/summary&gt;\r\n\/\/\/ &lt;param name=\"AName\"&gt;\u8981\u76d1\u542c\u7684\u901a\u77e5\u540d\u79f0&lt;\/param&gt;\r\nprocedure Listen(const AName: QStringW); virtual;\r\n\/\/\/ &lt;summary&gt;\u53d6\u6d88\u5bf9\u6307\u5b9a\u540d\u79f0\u7684\u901a\u77e5\u7684\u76d1\u542c&lt;\/summary&gt;\r\nprocedure Unlisten(const AName: QStringW); virtual;\r\n\/\/\/ &lt;summary&gt;\u89e6\u53d1\u670d\u52a1\u5668\u4e0a\u7279\u5b9a\u540d\u79f0\u7684\u901a\u77e5&lt;\/summary&gt;\r\n\/\/\/ &lt;param name=\"AName\"&gt;\u8981\u53d1\u9001\u7684\u901a\u77e5\u540d\u79f0&lt;\/param&gt;\r\n\/\/\/ &lt;param name=\"APayload\"&gt;\u8981\u53d1\u9001\u7684\u901a\u77e5\u5185\u5bb9\u5b57\u7b26\u4e32&lt;\/param&gt;\r\nprocedure Notify(const AName: QStringW; const APayload: QStringW); virtual;<\/pre>\n<p>Listen\/Unlisten\/ Notify\u5206\u522b\u5bf9\u5e94 PgSQL \u7684\u76f8\u5e94\u64cd\u4f5c\uff0c\u4e00\u65e6\u63a5\u6536\u5230\u670d\u52a1\u5668\u7aef\u53d1\u9001\u7684\u901a\u77e5\uff0cTQProvider.OnNotify\u4e8b\u4ef6\u5c31\u4f1a\u89e6\u53d1\uff0c\u7136\u540e\u5269\u4e0b\u7684\u5c31\u662f\u4f60\u81ea\u5df1\u7684\u4ee3\u7801\u5904\u7406\u4e86\uff0c\u770b\u8d77\u6765\u4f1a\u5f88\u65b9\u4fbf\u7684\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>PostgreSQL \u652f\u6301\u4ece\u670d\u52a1\u5668\u7aef\u5411\u5ba2 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[4,66],"tags":[],"class_list":["post-1696","post","type-post","status-publish","format-standard","hentry","category-pgsql","category-qdb"],"views":3540,"_links":{"self":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/1696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1696"}],"version-history":[{"count":1,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/1696\/revisions"}],"predecessor-version":[{"id":1697,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=\/wp\/v2\/posts\/1696\/revisions\/1697"}],"wp:attachment":[{"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.qdac.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}