{"id":179028,"date":"2024-11-08T22:24:22","date_gmt":"2024-11-08T14:24:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179028\/"},"modified":"2024-11-08T22:24:24","modified_gmt":"2024-11-08T14:24:24","slug":"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9-postgresql-%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a42p05-duplicate_prepared_statement%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179028\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42P05 &#8211; duplicate_prepared_statement\uff1f"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9-postgresql-%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a42p05-duplicate_prepared_statement-RfiiRuQuoe\">\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42P05 &#8211; duplicate_prepared_statement<\/h1>\n<p>\u5728\u4f7f\u7528 PostgreSQL \u6578\u64da\u5eab\u6642\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u9047\u5230\u5404\u7a2e\u932f\u8aa4\u4ee3\u78bc\uff0c\u5176\u4e2d\u4e4b\u4e00\u662f\u932f\u8aa4\u4ee3\u78bc 42P05\uff0c\u8a72\u932f\u8aa4\u8868\u793a\u300cduplicate_prepared_statement\u300d\u3002\u9019\u610f\u5473\u8457\u5728\u540c\u4e00\u500b\u6703\u8a71\u4e2d\uff0c\u5617\u8a66\u6e96\u5099\u4e00\u500b\u5df2\u7d93\u5b58\u5728\u7684\u8a9e\u53e5\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0e\u9019\u500b\u932f\u8aa4\u7684\u539f\u56e0\u3001\u5f71\u97ff\u4ee5\u53ca\u5982\u4f55\u6709\u6548\u5730\u4fee\u5fa9\u5b83\u3002<\/p>\n<h2 id=\"%e9%8c%af%e8%aa%a4%e5%8e%9f%e5%9b%a0-RfiiRuQuoe\">\u932f\u8aa4\u539f\u56e0<\/h2>\n<p>PostgreSQL \u7684\u300cduplicate_prepared_statement\u300d\u932f\u8aa4\u901a\u5e38\u767c\u751f\u5728\u4ee5\u4e0b\u60c5\u6cc1\uff1a<\/p>\n<ul>\n<li><strong>\u91cd\u8907\u7684\u8a9e\u53e5\u540d\u7a31\uff1a<\/strong>\u7576\u4f60\u5728\u540c\u4e00\u500b\u6703\u8a71\u4e2d\u4f7f\u7528\u76f8\u540c\u7684\u540d\u7a31\u4f86\u6e96\u5099\u591a\u500b\u8a9e\u53e5\u6642\uff0cPostgreSQL \u6703\u5831\u544a\u6b64\u932f\u8aa4\u3002\u4f8b\u5982\uff0c\u5982\u679c\u4f60\u5df2\u7d93\u6e96\u5099\u4e86\u4e00\u500b\u540d\u70ba &#8220;my_statement&#8221; \u7684\u8a9e\u53e5\uff0c\u7136\u5f8c\u518d\u6b21\u5617\u8a66\u6e96\u5099\u4e00\u500b\u540c\u540d\u7684\u8a9e\u53e5\uff0c\u5c31\u6703\u51fa\u73fe\u6b64\u932f\u8aa4\u3002<\/li>\n<li><strong>\u6703\u8a71\u7ba1\u7406\u4e0d\u7576\uff1a<\/strong>\u5728\u591a\u7dda\u7a0b\u6216\u591a\u7528\u6236\u74b0\u5883\u4e2d\uff0c\u82e5\u6703\u8a71\u7ba1\u7406\u4e0d\u7576\uff0c\u53ef\u80fd\u6703\u5c0e\u81f4\u540c\u4e00\u500b\u8a9e\u53e5\u5728\u4e0d\u540c\u7684\u7dda\u7a0b\u4e2d\u88ab\u91cd\u8907\u6e96\u5099\u3002<\/li>\n<li><strong>\u61c9\u7528\u7a0b\u5f0f\u908f\u8f2f\u932f\u8aa4\uff1a<\/strong>\u5982\u679c\u61c9\u7528\u7a0b\u5f0f\u7684\u908f\u8f2f\u4e0d\u6b63\u78ba\uff0c\u53ef\u80fd\u6703\u5c0e\u81f4\u91cd\u8907\u6e96\u5099\u8a9e\u53e5\u7684\u60c5\u6cc1\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9%e9%8c%af%e8%aa%a4-RfiiRuQuoe\">\u5982\u4f55\u4fee\u5fa9\u932f\u8aa4<\/h2>\n<p>\u4fee\u5fa9 PostgreSQL \u7684 42P05 \u932f\u8aa4\u53ef\u4ee5\u901a\u904e\u4ee5\u4e0b\u5e7e\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\uff1a<\/p>\n<h3 id=\"1-%e6%aa%a2%e6%9f%a5%e8%aa%9e%e5%8f%a5%e5%90%8d%e7%a8%b1-RfiiRuQuoe\">1. \u6aa2\u67e5\u8a9e\u53e5\u540d\u7a31<\/h3>\n<p>\u9996\u5148\uff0c\u6aa2\u67e5\u4f60\u7684 SQL \u8a9e\u53e5\u540d\u7a31\uff0c\u78ba\u4fdd\u5728\u540c\u4e00\u500b\u6703\u8a71\u4e2d\u4e0d\u6703\u91cd\u8907\u4f7f\u7528\u76f8\u540c\u7684\u540d\u7a31\u3002\u4f60\u53ef\u4ee5\u4f7f\u7528\u4e0d\u540c\u7684\u540d\u7a31\u4f86\u6e96\u5099\u65b0\u7684\u8a9e\u53e5\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>PREPARE my_statement AS SELECT * FROM my_table;\nPREPARE my_statement_2 AS SELECT * FROM my_table WHERE id = $1;<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8-deallocate-%e9%87%8b%e6%94%be%e8%aa%9e%e5%8f%a5-RfiiRuQuoe\">2. \u4f7f\u7528 DEALLOCATE \u91cb\u653e\u8a9e\u53e5<\/h3>\n<p>\u5982\u679c\u4f60\u78ba\u5be6\u9700\u8981\u91cd\u65b0\u6e96\u5099\u4e00\u500b\u8a9e\u53e5\uff0c\u53ef\u4ee5\u5728\u6e96\u5099\u4e4b\u524d\u4f7f\u7528 <code>DEALLOCATE<\/code> \u547d\u4ee4\u4f86\u91cb\u653e\u5df2\u7d93\u5b58\u5728\u7684\u8a9e\u53e5\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>DEALLOCATE my_statement;\nPREPARE my_statement AS SELECT * FROM my_table;<\/code><\/pre>\n<h3 id=\"3-%e6%aa%a2%e6%9f%a5%e6%87%89%e7%94%a8%e7%a8%8b%e5%bc%8f%e9%82%8f%e8%bc%af-RfiiRuQuoe\">3. \u6aa2\u67e5\u61c9\u7528\u7a0b\u5f0f\u908f\u8f2f<\/h3>\n<p>\u6aa2\u67e5\u4f60\u7684\u61c9\u7528\u7a0b\u5f0f\u908f\u8f2f\uff0c\u78ba\u4fdd\u5728\u6e96\u5099\u8a9e\u53e5\u6642\u4e0d\u6703\u91cd\u8907\u57f7\u884c\u76f8\u540c\u7684\u4ee3\u78bc\u3002\u9019\u53ef\u4ee5\u901a\u904e\u6dfb\u52a0\u689d\u4ef6\u4f86\u6aa2\u67e5\u8a9e\u53e5\u662f\u5426\u5df2\u7d93\u5b58\u5728\u4f86\u5be6\u73fe\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>IF NOT EXISTS (SELECT 1 FROM pg_prepared_statements WHERE name = 'my_statement') THEN\n    PREPARE my_statement AS SELECT * FROM my_table;\nEND IF;<\/code><\/pre>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8%e4%b8%8d%e5%90%8c%e7%9a%84%e6%9c%83%e8%a9%b1-RfiiRuQuoe\">4. \u4f7f\u7528\u4e0d\u540c\u7684\u6703\u8a71<\/h3>\n<p>\u5728\u591a\u7dda\u7a0b\u6216\u591a\u7528\u6236\u74b0\u5883\u4e2d\uff0c\u8003\u616e\u4f7f\u7528\u4e0d\u540c\u7684\u6703\u8a71\u4f86\u6e96\u5099\u8a9e\u53e5\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u56e0\u70ba\u6703\u8a71\u91cd\u8907\u800c\u5c0e\u81f4\u7684\u932f\u8aa4\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-RfiiRuQuoe\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL \u7684\u932f\u8aa4\u4ee3\u78bc 42P05 &#8211; duplicate_prepared_statement \u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u901a\u5e38\u7531\u65bc\u91cd\u8907\u7684\u8a9e\u53e5\u540d\u7a31\u6216\u4e0d\u7576\u7684\u6703\u8a71\u7ba1\u7406\u5f15\u8d77\u3002\u901a\u904e\u6aa2\u67e5\u8a9e\u53e5\u540d\u7a31\u3001\u4f7f\u7528 <code>DEALLOCATE<\/code> \u547d\u4ee4\u3001\u6aa2\u67e5\u61c9\u7528\u7a0b\u5f0f\u908f\u8f2f\u4ee5\u53ca\u4f7f\u7528\u4e0d\u540c\u7684\u6703\u8a71\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u4fee\u5fa9\u6b64\u932f\u8aa4\u3002\u5c0d\u65bc\u9700\u8981\u7a69\u5b9a\u548c\u9ad8\u6548\u6578\u64da\u5eab\u7ba1\u7406\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u6574\u9ad4\u6027\u80fd\u548c\u53ef\u9760\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc 42P05 &#8211; duplicate_prepared_statement\uff0c\u89e3\u6c7a\u91cd\u8907\u7684\u9810\u5099\u8a9e\u53e5\u554f\u984c\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\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-179028","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179028","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=179028"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179028\/revisions"}],"predecessor-version":[{"id":179029,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179028\/revisions\/179029"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179028"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179028"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179028"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}