{"id":21417,"date":"2024-01-02T09:02:19","date_gmt":"2024-01-02T09:02:19","guid":{"rendered":"https:\/\/server.hk\/blog\/21417\/"},"modified":"2024-11-14T10:34:48","modified_gmt":"2024-11-14T02:34:48","slug":"how-to-fix-postgresql-error-code-42701-duplicate_column","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/21417\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42701 – duplicate_column"},"content":{"rendered":"

\u5982\u4f55\u4fee\u5fa9 PostgreSQL \u932f\u8aa4\u4ee3\u78bc\uff1a42701 – duplicate_column<\/h1>\n

PostgreSQL \u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u7528\u65bc\u5404\u7a2e\u61c9\u7528\u7a0b\u5e8f\u3002\u7136\u800c\uff0c\u50cf\u5176\u4ed6\u8edf\u4ef6\u4e00\u6a23\uff0c\u5b83\u4e5f\u53ef\u80fd\u9047\u5230\u9700\u8981\u89e3\u6c7a\u7684\u932f\u8aa4\u3002PostgreSQL \u7528\u6236\u53ef\u80fd\u6703\u9047\u5230\u7684\u4e00\u500b\u5e38\u898b\u932f\u8aa4\u662f\u932f\u8aa4\u4ee3\u78bc 42701 \u7684 “duplicate_column” \u932f\u8aa4\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u5c07\u63a2\u8a0e\u6b64\u932f\u8aa4\u7684\u6210\u56e0\uff0c\u4e26\u63d0\u4f9b\u9010\u6b65\u7684\u4fee\u5fa9\u6307\u5c0e\u3002<\/p>\n

\u7406\u89e3\u932f\u8aa4<\/h2>\n

“duplicate_column” \u932f\u8aa4\u767c\u751f\u5728\u60a8\u5617\u8a66\u5411\u4e00\u500b\u5df2\u7d93\u6709\u540c\u540d\u5217\u7684\u8868\u4e2d\u6dfb\u52a0\u65b0\u5217\u6642\u3002PostgreSQL \u5728\u8868\u5167\u5f37\u5236\u57f7\u884c\u5217\u540d\u7684\u552f\u4e00\u6027\uff0c\u56e0\u6b64\u5617\u8a66\u6dfb\u52a0\u91cd\u8907\u7684\u5217\u5c07\u5c0e\u81f4\u6b64\u932f\u8aa4\u3002<\/p>\n

\u4ee5\u4e0b\u662f\u60a8\u53ef\u80fd\u9047\u5230\u7684\u932f\u8aa4\u6d88\u606f\u793a\u4f8b\uff1a<\/p>\n

ERROR: column \"column_name\" of relation \"table_name\" already exists<\/code><\/p>\n

\u4fee\u5fa9\u932f\u8aa4<\/h2>\n

\u8981\u4fee\u5fa9 “duplicate_column” \u932f\u8aa4\uff0c\u60a8\u6709\u5e7e\u500b\u9078\u64c7\uff1a<\/p>\n

1. \u91cd\u65b0\u547d\u540d\u73fe\u6709\u5217<\/h3>\n

\u5982\u679c\u73fe\u6709\u5217\u4e0d\u518d\u9700\u8981\u6216\u53ef\u4ee5\u91cd\u65b0\u547d\u540d\uff0c\u60a8\u53ef\u4ee5\u5728\u6dfb\u52a0\u65b0\u5217\u4e4b\u524d\u5c07\u5176\u91cd\u65b0\u547d\u540d\u70ba\u4e0d\u540c\u7684\u540d\u7a31\u3002\u9019\u53ef\u4ee5\u4f7f\u7528 ALTER TABLE \u8a9e\u53e5\u548c RENAME COLUMN \u5b50\u53e5\u4f86\u5b8c\u6210\u3002<\/p>\n

ALTER TABLE table_name RENAME COLUMN column_name TO new_column_name;<\/code><\/p>\n

\u5728\u91cd\u65b0\u547d\u540d\u73fe\u6709\u5217\u5f8c\uff0c\u60a8\u53ef\u4ee5\u7e7c\u7e8c\u6dfb\u52a0\u65b0\u5217\uff0c\u800c\u4e0d\u6703\u9047\u5230\u932f\u8aa4\u3002<\/p>\n

2. \u522a\u9664\u73fe\u6709\u5217<\/h3>\n

\u5982\u679c\u73fe\u6709\u5217\u4e0d\u518d\u9700\u8981\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528 ALTER TABLE \u8a9e\u53e5\u548c DROP COLUMN \u5b50\u53e5\u522a\u9664\u5b83\u3002<\/p>\n

ALTER TABLE table_name DROP COLUMN column_name;<\/code><\/p>\n

\u5728\u522a\u9664\u73fe\u6709\u5217\u5f8c\uff0c\u60a8\u53ef\u4ee5\u6beb\u7121\u554f\u984c\u5730\u6dfb\u52a0\u65b0\u5217\u3002<\/p>\n

3. \u4f7f\u7528 IF NOT EXISTS \u5b50\u53e5<\/h3>\n

\u5982\u679c\u60a8\u5e0c\u671b\u50c5\u5728\u65b0\u5217\u5c1a\u4e0d\u5b58\u5728\u7684\u60c5\u6cc1\u4e0b\u6dfb\u52a0\u5b83\uff0c\u60a8\u53ef\u4ee5\u5728 ALTER TABLE \u8a9e\u53e5\u4e2d\u4f7f\u7528 IF NOT EXISTS \u5b50\u53e5\u3002<\/p>\n

ALTER TABLE table_name ADD COLUMN IF NOT EXISTS column_name data_type;<\/code><\/p>\n

\u9019\u6a23\uff0c\u5982\u679c\u8a72\u5217\u5df2\u5b58\u5728\uff0cPostgreSQL \u5c07\u4e0d\u6703\u5f15\u767c\u932f\u8aa4\uff0c\u4e26\u5c07\u7e7c\u7e8c\u57f7\u884c\u8a9e\u53e5\uff0c\u800c\u4e0d\u6703\u6dfb\u52a0\u91cd\u8907\u7684\u5217\u3002<\/p>\n

\u7d50\u8ad6<\/h2>\n

PostgreSQL \u4e2d\u7684 “duplicate_column” \u932f\u8aa4\u4ee3\u78bc 42701 \u767c\u751f\u5728\u60a8\u5617\u8a66\u5411\u4e00\u500b\u5df2\u7d93\u6709\u540c\u540d\u5217\u7684\u8868\u4e2d\u6dfb\u52a0\u65b0\u5217\u6642\u3002\u901a\u904e\u9075\u5faa\u672c\u6587\u4e2d\u6982\u8ff0\u7684\u6b65\u9a5f\uff0c\u60a8\u53ef\u4ee5\u901a\u904e\u91cd\u65b0\u547d\u540d\u73fe\u6709\u5217\u3001\u522a\u9664\u5b83\u6216\u5728\u6dfb\u52a0\u65b0\u5217\u6642\u4f7f\u7528 IF NOT EXISTS \u5b50\u53e5\u4f86\u89e3\u6c7a\u6b64\u932f\u8aa4\u3002<\/p>\n

\u5982\u9700\u4e86\u89e3\u6709\u95dc VPS \u8a17\u7ba1\u89e3\u6c7a\u65b9\u6848\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u8acb\u8a2a\u554f Server.HK<\/a>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5982\u4f55\u4fee\u5fa9 PostgreSQL ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-21417","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/21417","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=21417"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/21417\/revisions"}],"predecessor-version":[{"id":24076,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/21417\/revisions\/24076"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=21417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=21417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=21417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}