{"Entry":{"collection":"func","key":"pg-basetype","name":"pg_basetype","aliases":[],"metadata":{"changed_in":[],"changes":[{"descriptions_changed":false,"doc_overhaul":false,"from":"16","group_changed":null,"signatures":{"added":[],"removed":[]},"status":"added","to":"17"}],"content_hash":"e83aa824420d7dd6e6364fb9eb102a274f392c5fcd513facaef2b48317ab9564","first_version":"17","group":"info","group_label":"System Information Functions And Operators","groups":["info"],"imported_at":"2026-09-27T17:57:29.119902+08:00","last_version":"20","name":"pg_basetype","name_key":"pg_basetype","position":28035,"present_in":["17","18","19","20"],"signature":"pg_basetype ( regtype ) → regtype","signature_count":1,"slug":"pg-basetype","source_rev":"b7bd9cda","summary":"Returns the OID of the base type of a domain identified by its type OID.","summary_zh":""}},"Definition":{"Collection":"func","Key":"pg-basetype","SourceDatabase":"center","Version":"18","SourceTable":"func","SourceKey":"pg-basetype","SourceRevision":"b7bd9cda","Facts":{"description":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_html":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_zh":"","description_zh_html":"","doc":{"anchor":"FUNCTIONS-INFO-CATALOG-TABLE","file":"functions-info.html","slug":"18"},"group":"info","group_label":"System Information Functions And Operators","lang":"en","layout":"table-new","pages":["functions-info.html"],"prose_only":false,"signatures":[{"description":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_html":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_zh":"","description_zh_html":"","examples":[{"expr":"pg_basetype('mytext'::regtype)","result":"text"}],"html":"\u003ccode class=\"function\"\u003epg_basetype\u003c/code\u003e ( \u003ccode class=\"type\"\u003eregtype\u003c/code\u003e ) → \u003ccode class=\"returnvalue\"\u003eregtype\u003c/code\u003e","returns":"regtype","text":"pg_basetype ( regtype ) → regtype","zh_from":""}],"zh_from":""},"ManualEvidence":{"doc":{"anchor":"FUNCTIONS-INFO-CATALOG-TABLE","file":"functions-info.html","slug":"18"}},"MeasuredEvidence":{}},"Text":{"Collection":"func","Key":"pg-basetype","SourceDatabase":"pgweb","Version":"18","Locale":"zh-Hans","Title":"pg_basetype","Summary":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","BodyHTML":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。\u003cpre\u003epg_basetype ( regtype ) → regtype\u003c/pre\u003e返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","SourceRevision":"ca936764","ContentHash":"73abef1a8de3799c42c3841e1b7e98ffc55fa1331d29ecadc593fdb4cb062ad7","Payload":{"description_zh":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","description_zh_html":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","signatures":[{"description_zh":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","description_zh_html":"返回由类型 OID 标识的域的基础类型 OID。如果参数是非域类型的 OID，则原样返回该参数。如果参数不是有效的类型 OID，则返回 NULL。如果存在域依赖链，则递归查找，直到找到基础类型。","returns":"regtype","text":"pg_basetype ( regtype ) → regtype","zh_from":"doc"}],"zh_from":"doc"}},"RequestedLocale":"zh-Hans","Fallback":false,"Versions":["17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":[{"Version":"18","Ordinal":0,"Hash":"42e087d8ce82c10efad3b0dfcb1bac1d3d15c8e92c0c3ee04c869bb0cd0a2f82","Text":"pg_basetype ( regtype ) → regtype","Returns":"regtype","Payload":{"description":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_html":"Returns the OID of the base type of a domain identified by its type OID. If the argument is the OID of a non-domain type, returns the argument as-is. Returns NULL if the argument is not a valid type OID. If there's a chain of domain dependencies, it will recurse until finding the base type.","description_zh":"","description_zh_html":"","examples":[{"expr":"pg_basetype('mytext'::regtype)","result":"text"}],"html":"\u003ccode class=\"function\"\u003epg_basetype\u003c/code\u003e ( \u003ccode class=\"type\"\u003eregtype\u003c/code\u003e ) → \u003ccode class=\"returnvalue\"\u003eregtype\u003c/code\u003e","returns":"regtype","text":"pg_basetype ( regtype ) → regtype","zh_from":""}}],"Spellings":null,"SQLState":null,"Evidence":null}