{"id":179012,"date":"2024-11-08T22:16:18","date_gmt":"2024-11-08T14:16:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179012\/"},"modified":"2024-11-08T22:16:18","modified_gmt":"2024-11-08T14:16:18","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%9a42846-cannot_coerce%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179012\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42846 &#8211; cannot_coerce\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%9a42846-cannot_coerce-AiGFKuierJ\">\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42846 &#8211; cannot_coerce<\/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 42846\uff0c\u8a72\u932f\u8aa4\u901a\u5e38\u986f\u793a\u70ba &#8220;cannot_coerce&#8221;\u3002\u9019\u500b\u932f\u8aa4\u901a\u5e38\u767c\u751f\u5728\u5617\u8a66\u5c07\u4e00\u7a2e\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u4e0d\u517c\u5bb9\u7684\u6578\u64da\u985e\u578b\u6642\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u9019\u500b\u932f\u8aa4\u7684\u539f\u56e0\u53ca\u5176\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n<h2 id=\"%e9%8c%af%e8%aa%a4%e5%8e%9f%e5%9b%a0-AiGFKuierJ\">\u932f\u8aa4\u539f\u56e0<\/h2>\n<p>PostgreSQL \u662f\u4e00\u500b\u5f37\u5927\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u652f\u6301\u591a\u7a2e\u6578\u64da\u985e\u578b\u3002\u5728\u9032\u884c\u6578\u64da\u64cd\u4f5c\u6642\uff0c\u6578\u64da\u985e\u578b\u7684\u517c\u5bb9\u6027\u81f3\u95dc\u91cd\u8981\u3002\u932f\u8aa4\u4ee3\u78bc 42846 \u901a\u5e38\u51fa\u73fe\u5728\u4ee5\u4e0b\u60c5\u6cc1\uff1a<\/p>\n<ul>\n<li><strong>\u4e0d\u517c\u5bb9\u7684\u6578\u64da\u985e\u578b\uff1a<\/strong>\u7576\u4f60\u5617\u8a66\u5c07\u4e00\u500b\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u500b\u4e0d\u517c\u5bb9\u7684\u6578\u64da\u985e\u578b\u6642\uff0c\u4f8b\u5982\u5c07\u4e00\u500b\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u6574\u6578\uff0cPostgreSQL \u6703\u5831\u544a\u6b64\u932f\u8aa4\u3002<\/li>\n<li><strong>\u51fd\u6578\u6216\u64cd\u4f5c\u7b26\u4e0d\u652f\u6301\u7684\u985e\u578b\uff1a<\/strong>\u67d0\u4e9b\u51fd\u6578\u6216\u64cd\u4f5c\u7b26\u53ef\u80fd\u4e0d\u652f\u6301\u7279\u5b9a\u7684\u6578\u64da\u985e\u578b\uff0c\u9019\u6703\u5c0e\u81f4\u985e\u4f3c\u7684\u932f\u8aa4\u3002<\/li>\n<li><strong>\u7f3a\u5c11\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db\uff1a<\/strong>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0cPostgreSQL \u9700\u8981\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db\u4f86\u9032\u884c\u64cd\u4f5c\uff0c\u5982\u679c\u6c92\u6709\u63d0\u4f9b\uff0c\u5247\u6703\u5f15\u767c\u6b64\u932f\u8aa4\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-AiGFKuierJ\">\u5982\u4f55\u4fee\u5fa9\u932f\u8aa4<\/h2>\n<p>\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc 42846 \u7684\u65b9\u6cd5\u53d6\u6c7a\u65bc\u5177\u9ad4\u7684\u60c5\u6cc1\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u89e3\u6c7a\u65b9\u6848\uff1a<\/p>\n<h3 id=\"1-%e6%aa%a2%e6%9f%a5%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-AiGFKuierJ\">1. \u6aa2\u67e5\u6578\u64da\u985e\u578b<\/h3>\n<p>\u9996\u5148\uff0c\u6aa2\u67e5\u4f60\u6b63\u5728\u64cd\u4f5c\u7684\u6578\u64da\u985e\u578b\u3002\u4f7f\u7528 <code>SELECT<\/code> \u8a9e\u53e5\u4f86\u67e5\u770b\u8868\u4e2d\u5217\u7684\u6578\u64da\u985e\u578b\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT column_name, data_type \nFROM information_schema.columns \nWHERE table_name = 'your_table_name';<\/code><\/pre>\n<p>\u78ba\u4fdd\u4f60\u5728\u9032\u884c\u64cd\u4f5c\u6642\u4f7f\u7528\u7684\u6578\u64da\u985e\u578b\u662f\u517c\u5bb9\u7684\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e6%98%8e%e7%a2%ba%e7%9a%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b-AiGFKuierJ\">2. \u4f7f\u7528\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db<\/h3>\n<p>\u5982\u679c\u4f60\u9700\u8981\u5c07\u4e00\u500b\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u500b\uff0c\u8acb\u4f7f\u7528\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db\u3002\u4f8b\u5982\uff0c\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u6574\u6578\u53ef\u4ee5\u9019\u6a23\u505a\uff1a<\/p>\n<pre><code>SELECT '123'::integer;<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u907f\u514d PostgreSQL \u81ea\u52d5\u8f49\u63db\u6642\u51fa\u73fe\u7684\u554f\u984c\u3002<\/p>\n<h3 id=\"3-%e6%aa%a2%e6%9f%a5%e5%87%bd%e6%95%b8%e5%92%8c%e6%93%8d%e4%bd%9c%e7%ac%a6-AiGFKuierJ\">3. \u6aa2\u67e5\u51fd\u6578\u548c\u64cd\u4f5c\u7b26<\/h3>\n<p>\u5982\u679c\u4f60\u5728\u4f7f\u7528\u67d0\u500b\u51fd\u6578\u6216\u64cd\u4f5c\u7b26\u6642\u9047\u5230\u6b64\u932f\u8aa4\uff0c\u8acb\u6aa2\u67e5\u8a72\u51fd\u6578\u6216\u64cd\u4f5c\u7b26\u662f\u5426\u652f\u6301\u4f60\u6240\u4f7f\u7528\u7684\u6578\u64da\u985e\u578b\u3002\u67e5\u95b1 PostgreSQL \u7684\u5b98\u65b9\u6587\u6a94\u4ee5\u7372\u53d6\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8-case-%e8%aa%9e%e5%8f%a5%e9%80%b2%e8%a1%8c%e6%a2%9d%e4%bb%b6%e8%bd%89%e6%8f%9b-AiGFKuierJ\">4. \u4f7f\u7528 CASE \u8a9e\u53e5\u9032\u884c\u689d\u4ef6\u8f49\u63db<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f60\u53ef\u80fd\u9700\u8981\u6839\u64da\u4e0d\u540c\u7684\u689d\u4ef6\u9032\u884c\u6578\u64da\u985e\u578b\u7684\u8f49\u63db\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528 <code>CASE<\/code> \u8a9e\u53e5\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT CASE \n           WHEN column_name IS NULL THEN 'default_value'::text \n           ELSE column_name::text \n       END \nFROM your_table_name;<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-AiGFKuierJ\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL \u932f\u8aa4\u4ee3\u78bc 42846 &#8211; cannot_coerce \u901a\u5e38\u662f\u7531\u65bc\u6578\u64da\u985e\u578b\u4e0d\u517c\u5bb9\u6216\u7f3a\u5c11\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db\u5f15\u8d77\u7684\u3002\u901a\u904e\u6aa2\u67e5\u6578\u64da\u985e\u578b\u3001\u4f7f\u7528\u660e\u78ba\u7684\u985e\u578b\u8f49\u63db\u3001\u6aa2\u67e5\u51fd\u6578\u548c\u64cd\u4f5c\u7b26\u7684\u517c\u5bb9\u6027\uff0c\u4ee5\u53ca\u4f7f\u7528 CASE \u8a9e\u53e5\u9032\u884c\u689d\u4ef6\u8f49\u63db\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u4fee\u5fa9\u6b64\u932f\u8aa4\u3002<\/p>\n<p>\u5982\u679c\u4f60\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\u4e0d\u540c\u9700\u6c42\u7684\u7528\u6236\u3002\u7121\u8ad6\u662f\u958b\u767c\u74b0\u5883\u9084\u662f\u751f\u7522\u74b0\u5883\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u4f60\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 42846 &#8211; cannot_coerce\uff0c\u89e3\u6c7a\u985e\u578b\u4e0d\u5339\u914d\u554f\u984c\uff0c\u78ba\u4fdd\u6578\u64da\u5eab\u67e5\u8a62\u6b63\u5e38\u904b\u884c\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-179012","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179012","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=179012"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179012\/revisions"}],"predecessor-version":[{"id":179013,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179012\/revisions\/179013"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179012"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179012"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179012"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}