{"Entry":{"collection":"func","key":"left","name":"left","aliases":[],"metadata":{"changed_in":[],"changes":[{"descriptions_changed":false,"doc_overhaul":false,"from":"9.0","group_changed":null,"signatures":{"added":[],"removed":[]},"status":"added","to":"9.1"},{"descriptions_changed":false,"doc_overhaul":true,"from":"12","group_changed":null,"signatures":{"added":[],"removed":[]},"status":"changed","to":"13"}],"content_hash":"d4c6b5913db40d8659656eb5c657b3ea8572afed1bef927d378c0fb8669cf0d7","derived_content_hash":"e9a69e5e3fdc53b5f06ff2dcf542de72fe919acc96811253e3cac523fda2b4f2","documentation_refresh":{"batch":"20261113","original_source_rev":"wiki-repair-20261023:ccff4f4d470adbaffbe76b1b43793d9036995fa9facaced92f792e422875e716","versions":{"14":"14.25","15":"15.20","16":"16.16","17":"17.12","18":"18.7","19":"19rc2"}},"first_version":"9.1","group":"string","group_label":"String Functions And Operators","groups":["string"],"imported_at":"2026-09-14T21:49:48.649695+08:00","last_version":"20","name":"left","name_key":"left","position":3012,"present_in":["9.1","9.2","9.3","9.4","9.5","9.6","10","11","12","13","14","15","16","17","18","19","20"],"repair_provenance":{"original_source_revision":"2026-09-14T13:14:25.684213+00:00@99e6866c","receipt_sha256":"7628f0fcf35025b473c6d6fd3e0c38e82e869d7dfb70d66208d6547010baa9fd","repair":"wiki-repair-20261023"},"signature":"left ( string text, n integer ) → text","signature_count":1,"slug":"left","source_rev":"wiki-repair-20261023:ccff4f4d470adbaffbe76b1b43793d9036995fa9facaced92f792e422875e716","summary":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","summary_zh":""}},"Definition":{"Collection":"func","Key":"left","SourceDatabase":"center","Version":"18","SourceTable":"func","SourceKey":"left","SourceRevision":"wiki-repair-20261023:ccff4f4d470adbaffbe76b1b43793d9036995fa9facaced92f792e422875e716","Facts":{"description":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","description_html":"Returns first \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","description_zh":"返回字符串最左侧的 n 个字符；如果 n 为负，则返回除最后 |n| 个字符之外的全部字符。","description_zh_html":"返回字符串最左侧的 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 个字符；如果 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 为负，则返回除最后 |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| 个字符之外的全部字符。","doc":{"anchor":"FUNCTIONS-STRING-OTHER","file":"functions-string.html","sha256":"dbe9f91e55c35969d99a8d2697b6f7bd5388a24ccc2b89706a666f176025f1e2","slug":"18"},"documentation_revision":{"inputs":[{"file":"functions-string.html","kind":"same-version-reviewed-manual","locale":"en","sha256":"dbe9f91e55c35969d99a8d2697b6f7bd5388a24ccc2b89706a666f176025f1e2","version":"18.7"},{"file":"functions-string.html","kind":"same-version-reviewed-manual","locale":"zh-Hans","sha256":"7eecd3bb343149124be0476a539f3c682476eab2a15489a0e0ad06fbb769ea9e","version":"18.7"}],"release":"18.7","runtime_remeasured":false,"source_revision":"pgdoc:b9f0e7232f60f380d642ac9b99226606c254b552"},"group":"string","group_label":"字符串函数和操作符","lang":"en","layout":"table-new","pages":["functions-string.html"],"prose_only":false,"signatures":[{"description":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","description_html":"Returns first \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","description_zh":"返回字符串最左侧的 n 个字符；如果 n 为负，则返回除最后 |n| 个字符之外的全部字符。","description_zh_html":"返回字符串最左侧的 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 个字符；如果 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 为负，则返回除最后 |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| 个字符之外的全部字符。","examples":[{"expr":"left('abcde', 2)","result":"ab"}],"html":"\u003ccode class=\"function\"\u003eleft\u003c/code\u003e ( \u003cem class=\"parameter\"\u003e\u003ccode\u003estring\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003etext\u003c/code\u003e, \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003einteger\u003c/code\u003e ) → \u003ccode class=\"returnvalue\"\u003etext\u003c/code\u003e","returns":"text","text":"left ( string text, n integer ) → text","zh_from":"same-version-manual"}],"translation_provenance":{"inputs":[{"kind":"current-pgdoc-translation","path":"/Users/vonng/pgsty/pgdoc/zh/18/html/functions-string.html","sha256":"0446377e0eccc9299099dc4b4b293204c337e3abefcdc396e9698bc54dd1080b"}],"kind":"same-version-pgdoc","locale":"zh-Hans","source_revision":"b1b500221dbe5437cfca004d6b04d3f6e422765d","version":"18"},"zh_from":"same-version-manual"},"ManualEvidence":{"doc":{"anchor":"FUNCTIONS-STRING-OTHER","file":"functions-string.html","sha256":"dbe9f91e55c35969d99a8d2697b6f7bd5388a24ccc2b89706a666f176025f1e2","slug":"18"}},"MeasuredEvidence":{}},"Text":{"Collection":"func","Key":"left","SourceDatabase":"center","Version":"18","Locale":"en","Title":"left","Summary":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","BodyHTML":"Returns first \u003cem\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","SourceRevision":"wiki-repair-20261023:ccff4f4d470adbaffbe76b1b43793d9036995fa9facaced92f792e422875e716","ContentHash":"547f28b5eb61abf1a73cbf58f823eff601a6e20497d0c1434dcbe4970e3f8c2d","Payload":{"description":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","description_html":"Returns first \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","signatures":[{"description":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","description_html":"Returns first \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","description_zh":"返回字符串最左侧的 n 个字符；如果 n 为负，则返回除最后 |n| 个字符之外的全部字符。","description_zh_html":"返回字符串最左侧的 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 个字符；如果 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 为负，则返回除最后 |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| 个字符之外的全部字符。","examples":[{"expr":"left('abcde', 2)","result":"ab"}],"html":"\u003ccode class=\"function\"\u003eleft\u003c/code\u003e ( \u003cem class=\"parameter\"\u003e\u003ccode\u003estring\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003etext\u003c/code\u003e, \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003einteger\u003c/code\u003e ) → \u003ccode class=\"returnvalue\"\u003etext\u003c/code\u003e","returns":"text","text":"left ( string text, n integer ) → text","zh_from":"same-version-manual"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20","9.1","9.2","9.3","9.4","9.5","9.6"],"Locales":["en","zh-Hans"],"Signatures":[{"Version":"18","Ordinal":0,"Hash":"3d2449ef143fb547f1ef8aa50fdd10d6c9546628127914abce1c8a815fda2de8","Text":"left ( string text, n integer ) → text","Returns":"text","Payload":{"description":"Returns first n characters in the string, or when n is negative, returns all but last |n| characters.","description_html":"Returns first \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e characters in the string, or when \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e is negative, returns all but last |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| characters.","description_zh":"返回字符串最左侧的 n 个字符；如果 n 为负，则返回除最后 |n| 个字符之外的全部字符。","description_zh_html":"返回字符串最左侧的 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 个字符；如果 \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e 为负，则返回除最后 |\u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e| 个字符之外的全部字符。","examples":[{"expr":"left('abcde', 2)","result":"ab"}],"html":"\u003ccode class=\"function\"\u003eleft\u003c/code\u003e ( \u003cem class=\"parameter\"\u003e\u003ccode\u003estring\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003etext\u003c/code\u003e, \u003cem class=\"parameter\"\u003e\u003ccode\u003en\u003c/code\u003e\u003c/em\u003e \u003ccode class=\"type\"\u003einteger\u003c/code\u003e ) → \u003ccode class=\"returnvalue\"\u003etext\u003c/code\u003e","returns":"text","text":"left ( string text, n integer ) → text","zh_from":"same-version-manual"}}],"Spellings":null,"SQLState":null,"Evidence":null}