{"id":179002,"date":"2024-11-08T22:11:20","date_gmt":"2024-11-08T14:11:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179002\/"},"modified":"2024-11-08T22:11:21","modified_gmt":"2024-11-08T14:11:21","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%9a42725-ambiguous_function%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179002\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42725 &#8211; ambiguous_function\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%9a42725-ambiguous_function-KUMezKWIRf\">\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42725 &#8211; ambiguous_function<\/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\u5c31\u662f\u932f\u8aa4\u4ee3\u78bc 42725\uff0c\u8a72\u932f\u8aa4\u901a\u5e38\u8868\u793a\u300c\u6a21\u7cca\u7684\u51fd\u6578\u300d\u3002\u9019\u610f\u5473\u8457\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528\u7684\u51fd\u6578\u540d\u7a31\u4e0d\u5920\u660e\u78ba\uff0c\u5c0e\u81f4\u6578\u64da\u5eab\u7121\u6cd5\u78ba\u5b9a\u61c9\u8a72\u8abf\u7528\u54ea\u4e00\u500b\u51fd\u6578\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u9019\u4e00\u932f\u8aa4\u7684\u6210\u56e0\u53ca\u5176\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n<h2 id=\"%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc-42725-%e7%9a%84%e6%88%90%e5%9b%a0-KUMezKWIRf\">\u932f\u8aa4\u4ee3\u78bc 42725 \u7684\u6210\u56e0<\/h2>\n<p>\u7576 PostgreSQL \u9047\u5230\u591a\u500b\u540c\u540d\u7684\u51fd\u6578\u6642\uff0c\u6703\u51fa\u73fe\u932f\u8aa4 42725\u3002\u9019\u901a\u5e38\u767c\u751f\u5728\u4ee5\u4e0b\u60c5\u6cc1\uff1a<\/p>\n<ul>\n<li><strong>\u51fd\u6578\u91cd\u8f09\uff1a<\/strong>\u5982\u679c\u5728\u6578\u64da\u5eab\u4e2d\u5b9a\u7fa9\u4e86\u591a\u500b\u540c\u540d\u4f46\u53c3\u6578\u985e\u578b\u4e0d\u540c\u7684\u51fd\u6578\uff0c\u7576\u8abf\u7528\u9019\u4e9b\u51fd\u6578\u6642\uff0c\u5982\u679c\u672a\u63d0\u4f9b\u8db3\u5920\u7684\u53c3\u6578\u4fe1\u606f\uff0c\u6578\u64da\u5eab\u5c07\u7121\u6cd5\u78ba\u5b9a\u61c9\u8a72\u4f7f\u7528\u54ea\u4e00\u500b\u51fd\u6578\u3002<\/li>\n<li><strong>\u7f3a\u5c11\u985e\u578b\u4fe1\u606f\uff1a<\/strong>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u7576\u51fd\u6578\u7684\u53c3\u6578\u985e\u578b\u4e0d\u660e\u78ba\u6642\uff0cPostgreSQL \u4e5f\u6703\u5831\u544a\u6b64\u932f\u8aa4\u3002<\/li>\n<li><strong>\u4f7f\u7528\u4e86\u4e0d\u6b63\u78ba\u7684\u6a21\u5f0f\uff1a<\/strong>\u5982\u679c\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528\u4e86\u4e0d\u6b63\u78ba\u7684\u6a21\u5f0f\uff0c\u53ef\u80fd\u6703\u5c0e\u81f4 PostgreSQL \u7121\u6cd5\u627e\u5230\u6b63\u78ba\u7684\u51fd\u6578\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9%e9%8c%af%e8%aa%a4-42725-KUMezKWIRf\">\u5982\u4f55\u4fee\u5fa9\u932f\u8aa4 42725<\/h2>\n<p>\u4fee\u5fa9 PostgreSQL \u932f\u8aa4 42725 \u7684\u65b9\u6cd5\u4e3b\u8981\u6709\u4ee5\u4e0b\u5e7e\u7a2e\uff1a<\/p>\n<h3 id=\"1-%e6%98%8e%e7%a2%ba%e6%8c%87%e5%ae%9a%e5%87%bd%e6%95%b8%e7%9a%84%e5%8f%83%e6%95%b8%e9%a1%9e%e5%9e%8b-KUMezKWIRf\">1. \u660e\u78ba\u6307\u5b9a\u51fd\u6578\u7684\u53c3\u6578\u985e\u578b<\/h3>\n<p>\u5728\u8abf\u7528\u51fd\u6578\u6642\uff0c\u660e\u78ba\u6307\u5b9a\u53c3\u6578\u7684\u985e\u578b\u53ef\u4ee5\u5e6b\u52a9 PostgreSQL \u78ba\u5b9a\u61c9\u8a72\u4f7f\u7528\u54ea\u4e00\u500b\u51fd\u6578\u3002\u4f8b\u5982\uff0c\u5047\u8a2d\u6709\u5169\u500b\u540d\u70ba <code>calculate<\/code> \u7684\u51fd\u6578\uff0c\u4e00\u500b\u63a5\u53d7\u6574\u6578\u53c3\u6578\uff0c\u53e6\u4e00\u500b\u63a5\u53d7\u6d6e\u9ede\u6578\u53c3\u6578\u3002\u53ef\u4ee5\u9019\u6a23\u8abf\u7528\uff1a<\/p>\n<pre><code>SELECT calculate(5::integer);  -- \u8abf\u7528\u6574\u6578\u7248\u672c\nSELECT calculate(5.0::float);    -- \u8abf\u7528\u6d6e\u9ede\u6578\u7248\u672c\n<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e5%87%bd%e6%95%b8%e7%9a%84%e5%ae%8c%e6%95%b4%e5%90%8d%e7%a8%b1-KUMezKWIRf\">2. \u4f7f\u7528\u51fd\u6578\u7684\u5b8c\u6574\u540d\u7a31<\/h3>\n<p>\u5982\u679c\u51fd\u6578\u5b58\u5728\u65bc\u7279\u5b9a\u7684\u6a21\u5f0f\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u6a21\u5f0f\u540d\u7a31\u4f86\u660e\u78ba\u6307\u5b9a\u51fd\u6578\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT schema_name.calculate(5);\n<\/code><\/pre>\n<h3 id=\"3-%e6%aa%a2%e6%9f%a5%e5%87%bd%e6%95%b8%e5%ae%9a%e7%be%a9-KUMezKWIRf\">3. \u6aa2\u67e5\u51fd\u6578\u5b9a\u7fa9<\/h3>\n<p>\u6aa2\u67e5\u6578\u64da\u5eab\u4e2d\u51fd\u6578\u7684\u5b9a\u7fa9\uff0c\u78ba\u4fdd\u6c92\u6709\u4e0d\u5fc5\u8981\u7684\u91cd\u8f09\u3002\u5982\u679c\u767c\u73fe\u91cd\u8f09\u7684\u51fd\u6578\u4e0d\u518d\u9700\u8981\uff0c\u53ef\u4ee5\u8003\u616e\u522a\u9664\u6216\u91cd\u547d\u540d\u5176\u4e2d\u4e00\u500b\u51fd\u6578\u3002<\/p>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8-cast-%e8%bd%89%e6%8f%9b%e9%a1%9e%e5%9e%8b-KUMezKWIRf\">4. \u4f7f\u7528 CAST \u8f49\u63db\u985e\u578b<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528 CAST \u53ef\u4ee5\u5e6b\u52a9 PostgreSQL \u78ba\u5b9a\u6b63\u78ba\u7684\u51fd\u6578\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT calculate(CAST(5 AS integer));\n<\/code><\/pre>\n<h2 id=\"%e7%a4%ba%e4%be%8b-KUMezKWIRf\">\u793a\u4f8b<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4ee5\u4e0b\u5169\u500b\u51fd\u6578\uff1a<\/p>\n<pre><code>CREATE FUNCTION calculate(integer) RETURNS integer AS $$ BEGIN RETURN $1 * 2; END; $$ LANGUAGE plpgsql;\nCREATE FUNCTION calculate(float) RETURNS float AS $$ BEGIN RETURN $1 * 2.0; END; $$ LANGUAGE plpgsql;\n<\/code><\/pre>\n<p>\u5982\u679c\u6211\u5011\u57f7\u884c\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT calculate(5);\n<\/code><\/pre>\n<p>\u9019\u5c07\u5c0e\u81f4\u932f\u8aa4 42725\uff0c\u56e0\u70ba PostgreSQL \u7121\u6cd5\u78ba\u5b9a\u61c9\u8a72\u8abf\u7528\u54ea\u4e00\u500b <code>calculate<\/code> \u51fd\u6578\u3002\u70ba\u4e86\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff0c\u6211\u5011\u53ef\u4ee5\u660e\u78ba\u6307\u5b9a\u53c3\u6578\u985e\u578b\uff1a<\/p>\n<pre><code>SELECT calculate(5::integer);  -- \u6b63\u78ba\u8abf\u7528\u6574\u6578\u7248\u672c\n<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-KUMezKWIRf\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL \u932f\u8aa4\u4ee3\u78bc 42725 \u901a\u5e38\u662f\u7531\u65bc\u51fd\u6578\u540d\u7a31\u6a21\u7cca\u5f15\u8d77\u7684\u3002\u901a\u904e\u660e\u78ba\u6307\u5b9a\u53c3\u6578\u985e\u578b\u3001\u4f7f\u7528\u5b8c\u6574\u7684\u51fd\u6578\u540d\u7a31\u3001\u6aa2\u67e5\u51fd\u6578\u5b9a\u7fa9\u4ee5\u53ca\u4f7f\u7528 CAST \u8f49\u63db\u985e\u578b\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u89e3\u6c7a\u6b64\u554f\u984c\u3002\u4e86\u89e3\u9019\u4e9b\u89e3\u6c7a\u65b9\u6848\u5c07\u6709\u52a9\u65bc\u958b\u767c\u8005\u5728\u4f7f\u7528 PostgreSQL \u6642\u66f4\u6709\u6548\u5730\u8655\u7406\u51fd\u6578\u8abf\u7528\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u670d\u52a1\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc 42725\uff1a\u6a21\u7cca\u51fd\u6578\u554f\u984c\uff0c\u63d0\u4f9b\u89e3\u6c7a\u65b9\u6848\u548c\u6700\u4f73\u5be6\u8e10\u4ee5\u907f\u514d\u6b64\u932f\u8aa4\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-179002","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179002","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=179002"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179002\/revisions"}],"predecessor-version":[{"id":179003,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179002\/revisions\/179003"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179002"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179002"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179002"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}