{"Entry":{"collection":"operator","key":"op-2d3e-json-int4","name":"-\u003e(json,int4)","aliases":["-\u003e","-\u003e(json,int4)"],"metadata":{"aliases":["-\u003e","-\u003e(json,int4)"],"category":"JSON","content_hash":"4a67f10c7af6d658185f0b333220fb981f95a0d8b8028ed06f0b6163822ac9db","derived_content_hash":"23b77477251f06b8173ea9fb2d1f902021bf2abc431c36078325fa0484d674fa","imported_at":"2026-09-30T00:40:40.980495+08:00","name":"-\u003e(json,int4)","name_zh":"","slug":"op-2d3e-json-int4","summary":"get json array element"}},"Definition":{"Collection":"operator","Key":"op-2d3e-json-int4","SourceDatabase":"center","Version":"18","SourceTable":"pg_operator_entry","SourceKey":"op-2d3e-json-int4","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","Facts":{"aliases":["-\u003e","-\u003e(json,int4)"],"comparison_data":{"memberships":[],"operator":{"commutator":"","function":"json_array_element(json,int4)","hash_join":"f","kind":"b","left_type":"json","merge_join":"f","negator":"","result_type":"json","right_type":"int4","symbol":"-\u003e"}},"comparison_hash":"abaa826d9bd6b9f087053913d1191bdf8bf0402404f78b84170167c3c8d53cf9","description":["get json array element"],"description_zh":"获取 JSON 数组元素。","description_zh_html":"\u003cp\u003e获取 JSON 数组元素。\u003c/p\u003e\u003cdl\u003e\u003cdt\u003e种类\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003eb\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e符号\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003e-\u0026gt;\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e实现函数\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003ejson_array_element(json,int4)\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e可用于哈希连接\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003e否\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e左操作数类型\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003ejson\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e可用于归并连接\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003e否\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e右操作数类型\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003eint4\u003c/code\u003e\u003c/dd\u003e\u003cdt\u003e结果类型\u003c/dt\u003e\u003cdd\u003e\u003ccode\u003ejson\u003c/code\u003e\u003c/dd\u003e\u003c/dl\u003e\u003ch3\u003e同版本中文手册节选\u003c/h3\u003e\u003cp class=\"title\"\u003e\u003cstrong\u003e表 9.47. \u003ccode class=\"type\"\u003ejson\u003c/code\u003e 和 \u003ccode class=\"type\"\u003ejsonb\u003c/code\u003e 操作符\u003c/strong\u003e\u003c/p\u003e\u003cp\u003e\u003ca href=\"/zh/docs/18/functions-json.html#FUNCTIONS-JSON-OP-TABLE\"\u003e查看完整中文手册与上下文\u003c/a\u003e。\u003c/p\u003e\u003cp\u003e本页开头的中文说明为 PG.CENTER 对源码说明的翻译；手册节选保留对应版本中文文档原文。源码信息及手册示例不代表重新进行过运行测试。\u003c/p\u003e","facts":[{"label":"Left operand","value":"json"},{"label":"Right operand","value":"int4"},{"label":"Result type","value":"json"},{"label":"Implementing function","value":"json_array_element(json,int4)"},{"label":"Operator kind","value":"Binary"},{"label":"Hash join candidate","value":"no"},{"label":"Merge join candidate","value":"no"}],"facts_zh":[{"label":"左操作数","value":"json"},{"label":"右操作数","value":"int4"},{"label":"返回类型","value":"json"},{"label":"实现函数","value":"json_array_element(json,int4)"},{"label":"操作符种类","value":"Binary"},{"label":"可用于哈希连接","value":"否"},{"label":"可用于归并连接","value":"否"}],"manual_semantics":"Exact operand/result signature matched","memberships":[],"operator":{"commutator":"","function":"json_array_element(json,int4)","hash_join":"f","kind":"b","left_type":"json","merge_join":"f","negator":"","result_type":"json","right_type":"int4","symbol":"-\u003e"},"related":[{"label":"json data type","url":"/wiki/type/json/?v=18"},{"label":"int4 data type","url":"/wiki/type/int4/?v=18"}],"release":{"catalog_fingerprint":"deec62e0f0c649d9d0d058ddd0b16bf41afffd569c3fd73949ff0971ce5cabd6","channel":"stable","label":"18.6","major":"18","manual_fingerprint":"fefce9e478eb2afe5e17e869492bbedc67dce23d317f0a5257240113d6496ebc","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sections":[{"paragraphs":["Extracts n 'th element of JSON array (array elements are indexed from zero, but negative integers count from the end).","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e 2 → {\"c\":\"baz\"}","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e -3 → {\"a\":\"foo\"}"],"title":"English manual definition"},{"paragraphs":["The catalog pg_operator stores information about operators. See CREATE OPERATOR and Section 36.14 for more information."],"title":"Catalog interpretation"}],"sections_zh":[{"paragraphs":["提取JSON数组的第 n 个元素（数组元素从0开始索引，但负整数从末尾开始计数）。","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e 2 → {\"c\":\"baz\"}","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e -3 → {\"a\":\"foo\"}"],"title":"英文手册定义"},{"paragraphs":["目录 pg_operator 存储关于操作符的信息。详见 CREATE OPERATOR 和 第 36.14 节 。"],"title":"目录记录解读"}],"signature":"-\u003e(json,int4) → json","source_oid":"3964","sources":[{"label":"Matching PostgreSQL source archive","sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"label":"PostgreSQL 18 English manual: catalog-pg-operator.html","path":"catalog-pg-operator.html","sha256":"e0b1817914e5e8f9037955cd41e9a43584e9227fcc115784898ecdd9a6c0ecd6","url":"/docs/18/catalog-pg-operator.html"},{"label":"PostgreSQL 18 English manual: catalog-pg-amop.html","path":"catalog-pg-amop.html","sha256":"e65b90ee78eaf4b4da97ce5b08b972cee2e2660b882ec107be22eca47201f7d1","url":"/docs/18/catalog-pg-amop.html"},{"label":"PostgreSQL 18 English manual: functions-json.html","path":"functions-json.html","sha256":"5129ad5ed908a15ce4b8a7183a9676878f9acde4d474b28ad476d0c980b73897","url":"/docs/18/functions-json.html#FUNCTIONS-JSON-OP-TABLE"}],"tables":[],"tables_zh":[],"zh_from":{"authored_translation":"authored-translation-of-source-description","body_sha256":"5da9538f31b9581bdb0e31ac1080159c3f7294d1cdb8da8ee8cd573011dd41b1","kind":"same-version-chinese-manual-with-authored-translation-of-source-description","manual":{"anchor":"FUNCTIONS-JSON-OP-TABLE","build_id":107,"extraction":"concept-introduction","fragment_sha256":"66cda05f61d9ef0b654aac557ffeef97a517fb42e777d0dd696fc30e14b4af00","locale":"zh-Hans","page_key":"functions-json.html","source_hash":"a412feb14a229f1d9f14fa2d7735255aa297d5eb8f2971d744d9dfee659c7cca","source_revision":"unknown:rendered-translation-baseline","translated_from_revision":null,"translation_revision":"git:b1b500221dbe5437cfca004d6b04d3f6e422765d;html-sha256:08e987a66af27b98444a8057c256314eafa13611a3fb9e888214fc436824244b","url":"/zh/docs/18/functions-json.html#FUNCTIONS-JSON-OP-TABLE","version":"18"},"runtime_rerun":false,"source_facts_revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"}},"ManualEvidence":{"release":{"catalog_fingerprint":"deec62e0f0c649d9d0d058ddd0b16bf41afffd569c3fd73949ff0971ce5cabd6","channel":"stable","label":"18.6","major":"18","manual_fingerprint":"fefce9e478eb2afe5e17e869492bbedc67dce23d317f0a5257240113d6496ebc","ref":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2","revision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","source_sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f"},"sources":[{"label":"Matching PostgreSQL source archive","sha256":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","url":"https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2"},{"label":"PostgreSQL 18 English manual: catalog-pg-operator.html","path":"catalog-pg-operator.html","sha256":"e0b1817914e5e8f9037955cd41e9a43584e9227fcc115784898ecdd9a6c0ecd6","url":"/docs/18/catalog-pg-operator.html"},{"label":"PostgreSQL 18 English manual: catalog-pg-amop.html","path":"catalog-pg-amop.html","sha256":"e65b90ee78eaf4b4da97ce5b08b972cee2e2660b882ec107be22eca47201f7d1","url":"/docs/18/catalog-pg-amop.html"},{"label":"PostgreSQL 18 English manual: functions-json.html","path":"functions-json.html","sha256":"5129ad5ed908a15ce4b8a7183a9676878f9acde4d474b28ad476d0c980b73897","url":"/docs/18/functions-json.html#FUNCTIONS-JSON-OP-TABLE"}]},"MeasuredEvidence":{}},"Text":{"Collection":"operator","Key":"op-2d3e-json-int4","SourceDatabase":"center","Version":"18","Locale":"en","Title":"-\u003e(json,int4)","Summary":"get json array element","BodyHTML":"\u003cp\u003eget json array element\u003c/p\u003e","SourceRevision":"555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f","ContentHash":"709ba465fc401778183aacffc50eed0889bcee2361525dcad010b0cd43ba4fd6","Payload":{"description":["get json array element"],"related":[{"label":"json data type","url":"/wiki/type/json/?v=18"},{"label":"int4 data type","url":"/wiki/type/int4/?v=18"}],"sections":[{"paragraphs":["Extracts n 'th element of JSON array (array elements are indexed from zero, but negative integers count from the end).","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e 2 → {\"c\":\"baz\"}","'[{\"a\":\"foo\"},{\"b\":\"bar\"},{\"c\":\"baz\"}]'::json -\u003e -3 → {\"a\":\"foo\"}"],"title":"English manual definition"},{"paragraphs":["The catalog pg_operator stores information about operators. See CREATE OPERATOR and Section 36.14 for more information."],"title":"Catalog interpretation"}],"tables":[]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}
