{"id":178796,"date":"2024-11-08T20:58:19","date_gmt":"2024-11-08T12:58:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/178796\/"},"modified":"2024-11-08T20:58:19","modified_gmt":"2024-11-08T12:58:19","slug":"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9postgresql%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a2203g-sql_json_item_cannot_be_cast_to_target_type%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/178796\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc\uff1a2203G &#8211; sql_json_item_cannot_be_cast_to_target_type\uff1f"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9postgresql%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a2203g-sql_json_item_cannot_be_cast_to_target_type%ef%bc%9f-ZOlkJPeamV\">\u5982\u4f55\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc\uff1a2203G &#8211; sql_json_item_cannot_be_cast_to_target_type\uff1f<\/h1>\n<p>\u5728\u4f7f\u7528PostgreSQL\u9032\u884c\u6578\u64da\u5eab\u64cd\u4f5c\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\u78bc2203G\uff0c\u8a72\u932f\u8aa4\u901a\u5e38\u986f\u793a\u70ba\u201csql_json_item_cannot_be_cast_to_target_type\u201d\u3002\u9019\u500b\u932f\u8aa4\u4e3b\u8981\u8207JSON\u6578\u64da\u985e\u578b\u7684\u8f49\u63db\u6709\u95dc\uff0c\u7576\u4f60\u5617\u8a66\u5c07\u4e00\u500bJSON\u9805\u76ee\u8f49\u63db\u70ba\u4e0d\u517c\u5bb9\u7684\u6578\u64da\u985e\u578b\u6642\uff0c\u5c31\u6703\u51fa\u73fe\u9019\u500b\u932f\u8aa4\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%e5%88%86%e6%9e%90-ZOlkJPeamV\">\u932f\u8aa4\u539f\u56e0\u5206\u6790<\/h2>\n<p>PostgreSQL\u652f\u6301\u591a\u7a2e\u6578\u64da\u985e\u578b\uff0c\u5176\u4e2d\u5305\u62ecJSON\u548cJSONB\u3002\u9019\u4e9b\u6578\u64da\u985e\u578b\u5141\u8a31\u7528\u6236\u4ee5\u7d50\u69cb\u5316\u7684\u65b9\u5f0f\u5b58\u5132\u548c\u67e5\u8a62\u6578\u64da\u3002\u7136\u800c\uff0c\u7576\u4f60\u5617\u8a66\u5c07JSON\u6578\u64da\u8f49\u63db\u70ba\u5176\u4ed6\u6578\u64da\u985e\u578b\u6642\uff0c\u53ef\u80fd\u6703\u9047\u5230\u985e\u578b\u4e0d\u5339\u914d\u7684\u554f\u984c\u3002\u4f8b\u5982\uff0c\u7576\u4f60\u5617\u8a66\u5c07\u4e00\u500bJSON\u5c0d\u8c61\u4e2d\u7684\u67d0\u500b\u5b57\u6bb5\u8f49\u63db\u70ba\u6574\u6578\u985e\u578b\uff0c\u4f46\u8a72\u5b57\u6bb5\u5be6\u969b\u4e0a\u662f\u4e00\u500b\u5b57\u7b26\u4e32\u6642\uff0c\u5c31\u6703\u5f15\u767c2203G\u932f\u8aa4\u3002<\/p>\n<h3 id=\"%e5%b8%b8%e8%a6%8b%e5%a0%b4%e6%99%af-ZOlkJPeamV\">\u5e38\u898b\u5834\u666f<\/h3>\n<ul>\n<li>\u5617\u8a66\u5c07JSON\u4e2d\u7684\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u6574\u6578\u3002<\/li>\n<li>\u5c07JSON\u5c0d\u8c61\u4e2d\u7684\u5e03\u723e\u503c\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u3002<\/li>\n<li>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528\u4e0d\u6b63\u78ba\u7684\u985e\u578b\u8f49\u63db\u51fd\u6578\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%a7%a3%e6%b1%ba%e6%96%b9%e6%a1%88-ZOlkJPeamV\">\u89e3\u6c7a\u65b9\u6848<\/h2>\n<p>\u8981\u4fee\u5fa92203G\u932f\u8aa4\uff0c\u9996\u5148\u9700\u8981\u78ba\u5b9a\u5c0e\u81f4\u932f\u8aa4\u7684\u5177\u9ad4\u539f\u56e0\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-ZOlkJPeamV\">1. \u6aa2\u67e5\u6578\u64da\u985e\u578b<\/h3>\n<p>\u5728\u9032\u884c\u985e\u578b\u8f49\u63db\u4e4b\u524d\uff0c\u9996\u5148\u8981\u6aa2\u67e5JSON\u6578\u64da\u7684\u7d50\u69cb\u548c\u985e\u578b\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0bSQL\u67e5\u8a62\u4f86\u6aa2\u67e5JSON\u6578\u64da\uff1a<\/p>\n<pre><code>SELECT json_data-&gt;&gt;'key' AS value FROM your_table;<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u4f60\u7372\u53d6\u7684\u6578\u64da\u985e\u578b\u662f\u6b63\u78ba\u7684\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e6%ad%a3%e7%a2%ba%e7%9a%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e5%87%bd%e6%95%b8-ZOlkJPeamV\">2. \u4f7f\u7528\u6b63\u78ba\u7684\u985e\u578b\u8f49\u63db\u51fd\u6578<\/h3>\n<p>PostgreSQL\u63d0\u4f9b\u4e86\u591a\u7a2e\u985e\u578b\u8f49\u63db\u51fd\u6578\uff0c\u78ba\u4fdd\u4f7f\u7528\u6b63\u78ba\u7684\u51fd\u6578\u4f86\u9032\u884c\u8f49\u63db\u3002\u4f8b\u5982\uff0c\u4f7f\u7528<strong>CAST<\/strong>\u6216<strong>::<\/strong>\u904b\u7b97\u7b26\u4f86\u9032\u884c\u985e\u578b\u8f49\u63db\uff1a<\/p>\n<pre><code>SELECT (json_data-&gt;&gt;'key')::integer FROM your_table;<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u5728\u8f49\u63db\u6642\u4e0d\u6703\u51fa\u73fe\u985e\u578b\u4e0d\u5339\u914d\u7684\u554f\u984c\u3002<\/p>\n<h3 id=\"3-%e8%99%95%e7%90%86%e7%95%b0%e5%b8%b8%e6%83%85%e6%b3%81-ZOlkJPeamV\">3. \u8655\u7406\u7570\u5e38\u60c5\u6cc1<\/h3>\n<p>\u5728\u9032\u884c\u985e\u578b\u8f49\u63db\u6642\uff0c\u5efa\u8b70\u4f7f\u7528<strong>COALESCE<\/strong>\u51fd\u6578\u4f86\u8655\u7406\u53ef\u80fd\u7684\u7570\u5e38\u60c5\u6cc1\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT COALESCE((json_data-&gt;&gt;'key')::integer, 0) FROM your_table;<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u5728\u8f49\u63db\u5931\u6557\u6642\u63d0\u4f9b\u4e00\u500b\u9ed8\u8a8d\u503c\uff0c\u907f\u514d\u5f15\u767c\u932f\u8aa4\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-ZOlkJPeamV\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL\u7684\u932f\u8aa4\u4ee3\u78bc2203G\u901a\u5e38\u662f\u7531\u65bcJSON\u6578\u64da\u985e\u578b\u8f49\u63db\u4e0d\u7576\u5f15\u8d77\u7684\u3002\u901a\u904e\u6aa2\u67e5\u6578\u64da\u985e\u578b\u3001\u4f7f\u7528\u6b63\u78ba\u7684\u8f49\u63db\u51fd\u6578\u4ee5\u53ca\u8655\u7406\u7570\u5e38\u60c5\u6cc1\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u4fee\u5fa9\u9019\u4e00\u932f\u8aa4\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u81f3\u95dc\u91cd\u8981\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u7a69\u5b9a\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u7528\u6236\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc2203G\u7684\u6307\u5357\uff0c\u89e3\u6c7asql_json_item_cannot_be_cast_to_target_type\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-178796","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178796","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=178796"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178796\/revisions"}],"predecessor-version":[{"id":178797,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178796\/revisions\/178797"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=178796"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=178796"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=178796"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}