{"Entry":{"collection":"psql","key":"cmd-64-64","name":"\\dd","aliases":["\\dd","\\ddS","\\ddSx","\\ddx"],"metadata":{"aliases":["\\dd","\\ddS","\\ddSx","\\ddx"],"category":"Describe database objects","content_hash":"1fc6b6a9f660305e965230bd0006ec171526fc940a0c79a05bcfb084ead7c9ce","derived_content_hash":"1fd8adb0d285cf01ee629e08729a8ddf02b576058c9c53a208a35183b379a38d","documentation_refresh":{"batch":"20261113","original_source_rev":"","versions":{"14":"14.25","15":"15.20","16":"16.16","17":"17.12","18":"18.7","19":"19rc2"}},"imported_at":"2026-09-30T00:40:44.857442+08:00","name":"\\dd","name_zh":"","slug":"cmd-64-64","summary":"Shows the descriptions of objects of type constraint , operator class , operator family , rule , and trigger . All other comments may be viewed by the respective backslash commands for those object types."}},"Definition":{"Collection":"psql","Key":"cmd-64-64","SourceDatabase":"center","Version":"18","SourceTable":"psql_command","SourceKey":"cmd-64-64","SourceRevision":"1b2d62b4845aa46374f2cb680f95d3392322cc8128646992ae4e18d0e7084915","Facts":{"command":"\\dd","comparison_data":{"definition":"Shows the descriptions of objects of type constraint , operator class , operator family , rule , and trigger . All other comments may be viewed by the respective backslash commands for those object types. \\dd displays descriptions for objects matching the pattern , or of visible objects of the appropriate type if no argument is given. But in either case, only objects that have a description are listed. By default, only user-created objects are shown; supply a pattern or the S modifier to include system objects. If x is appended to the command name, the results are displayed in expanded mode. Descriptions for objects can be created with the COMMENT SQL command.","modifiers":[{"command":"\\dd","modifiers":"Sx"}],"signature":"\\dd[Sx] [ pattern ]","spellings":["\\dd"]},"comparison_hash":"f245b16c02d98a66694299aae5f9fa01b4a055b69c46d42b9ae85411be476798","description":["Shows the descriptions of objects of type constraint , operator class , operator family , rule , and trigger . All other comments may be viewed by the respective backslash commands for those object types."],"description_zh":"显示 constraint 、 operator class 、 operator family 、 rule 和 trigger 类型对象的描述。其他注释可通过对应对象类型的反斜线命令查看。","description_zh_html":"\u003cdd\u003e\u003cp\u003e\n        显示 \u003ccode class=\"literal\"\u003econstraint\u003c/code\u003e、\u003ccode class=\"literal\"\u003eoperator class\u003c/code\u003e、\u003ccode class=\"literal\"\u003eoperator family\u003c/code\u003e、\u003ccode class=\"literal\"\u003erule\u003c/code\u003e 和\n        \u003ccode class=\"literal\"\u003etrigger\u003c/code\u003e 类型对象的描述。其他注释可通过对应对象类型的反斜线命令查看。\n        \u003c/p\u003e\u003cp\u003e\u003ccode class=\"literal\"\u003e\\dd\u003c/code\u003e 显示与\n        \u003cem class=\"replaceable\"\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e 匹配的对象描述；如果没有给出参数，则显示相应类型的可见对象的描述。但无论哪种情况，只列出那些已有描述的对象。默认情况下，只显示用户创建的对象；提供模式或 \u003ccode class=\"literal\"\u003eS\u003c/code\u003e 修饰符可包括系统对象。如果在命令名后追加 \u003ccode class=\"literal\"\u003ex\u003c/code\u003e，结果会以扩展模式显示。\n        \u003c/p\u003e\u003cp\u003e\n        可以使用 \u003ca class=\"link\" href=\"/zh/docs/18/sql-comment.html\" title=\"COMMENT\"\u003e\u003ccode class=\"command\"\u003eCOMMENT\u003c/code\u003e\u003c/a\u003e \u003cacronym class=\"acronym\"\u003eSQL\u003c/acronym\u003e 命令创建对象的描述。\n       \u003c/p\u003e\u003c/dd\u003e","documentation_revision":{"inputs":[{"file":"app-psql.html","kind":"same-version-reviewed-manual","locale":"en","sha256":"af50448485df02bdef2b72b8347192ba029c7082b8d0392ecb17db44ad533aaf","version":"18.7"},{"file":"app-psql.html","kind":"same-version-reviewed-manual","locale":"zh-Hans","sha256":"cb475c53a16d9e06358f5e6c9c5649645db92568cfd319f230c62c9f57ae090b","version":"18.7"}],"release":"18.7","runtime_remeasured":false,"source_revision":"pgdoc:b9f0e7232f60f380d642ac9b99226606c254b552"},"facts":[{"label":"Client","value":"psql 18.7"},{"label":"Case-sensitive spelling","value":"\\dd"}],"facts_zh":[{"label":"客户端","value":"psql 18.7"},{"label":"区分大小写的写法","value":"\\dd"}],"localization":{"documentation_release":"18.7","language":"en","source_language":"en","source_revision":"pgdoc:b9f0e7232f60f380d642ac9b99226606c254b552","status":"same-version-reviewed-manual"},"manual_html":"\u003cdiv\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt id=\"APP-PSQL-META-COMMAND-DD-LC\"\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003e\\dd[Sx] [ \u003ca class=\"link\" href=\"/docs/18/app-psql.html#APP-PSQL-PATTERNS\" title=\"Patterns\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e\u003c/a\u003e ]\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n        Shows the descriptions of objects of type \u003ccode class=\"literal\"\u003econstraint\u003c/code\u003e,\n        \u003ccode class=\"literal\"\u003eoperator class\u003c/code\u003e, \u003ccode class=\"literal\"\u003eoperator family\u003c/code\u003e,\n        \u003ccode class=\"literal\"\u003erule\u003c/code\u003e, and \u003ccode class=\"literal\"\u003etrigger\u003c/code\u003e. All\n        other comments may be viewed by the respective backslash commands for\n        those object types.\n        \u003c/p\u003e\u003cp\u003e\u003ccode class=\"literal\"\u003e\\dd\u003c/code\u003e displays descriptions for objects matching the\n        \u003cem class=\"replaceable\"\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e, or of visible\n        objects of the appropriate type if no argument is given.  But in either\n        case, only objects that have a description are listed.\n        By default, only user-created objects are shown;  supply a\n        pattern or the \u003ccode class=\"literal\"\u003eS\u003c/code\u003e modifier to include system\n        objects.\n        If \u003ccode class=\"literal\"\u003ex\u003c/code\u003e is appended to the command name, the results\n        are displayed in expanded mode.\n        \u003c/p\u003e\u003cp\u003e\n        Descriptions for objects can be created with the \u003ca class=\"link\" href=\"/docs/18/sql-comment.html\" title=\"COMMENT\"\u003e\u003ccode class=\"command\"\u003eCOMMENT\u003c/code\u003e\u003c/a\u003e\nSQL command.\n       \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","manual_path":"app-psql.html#APP-PSQL-META-COMMAND-DD-LC","modifiers":[{"command":"\\dd","modifiers":"Sx"}],"related":[{"label":"psql command-line options and complete manual","url":"/wiki/tool/psql/?v=18"}],"related_zh":[{"label":"psql 命令行选项及完整手册","url":"/wiki/tool/psql/?v=18"}],"release":{"channel":"stable","evidence_kind":"English manual and source declarations","label":"18.7","major":"18","manifest":{"major":"18","release":"18.7","source_sha256":"441dfae4280cae3e0425e5f876f80559fb0731c140f1aae22b3e5a54d0411bfd","source_url":"https://ftp.postgresql.org/pub/source/v18.7/postgresql-18.7.tar.bz2"},"ref":"https://ftp.postgresql.org/pub/source/v18.7/postgresql-18.7.tar.bz2","revision":"1b2d62b4845aa46374f2cb680f95d3392322cc8128646992ae4e18d0e7084915","source_sha256":"441dfae4280cae3e0425e5f876f80559fb0731c140f1aae22b3e5a54d0411bfd"},"sections":[],"sections_zh":[],"signature":"\\dd[Sx] [ pattern ]","sources":[{"anchor":"APP-PSQL-META-COMMAND-DD-LC","file":"app-psql.html","label":"18.7 English manual · app-psql.html","sha256":"af50448485df02bdef2b72b8347192ba029c7082b8d0392ecb17db44ad533aaf","url":"/docs/18/app-psql.html#APP-PSQL-META-COMMAND-DD-LC"}],"spellings":["\\dd"],"tables":[{"columns":[{"key":"command","label":"Command"},{"key":"modifiers","label":"Documented suffix modifiers"}],"key":"spellings","rows":[{"command":{"text":"\\dd","url":"/wiki/psql/cmd-64-64/?v=18"},"modifiers":"Sx"}],"title":"Spellings in this manual definition"}],"tables_zh":[{"columns":[{"key":"command","label":"命令"},{"key":"modifiers","label":"手册中的后缀修饰符"}],"key":"spellings","rows":[{"command":{"text":"\\dd","url":"/wiki/psql/cmd-64-64/?v=18"},"modifiers":"Sx"}],"title":"本版手册中的写法"}],"zh_from":"same-version-manual"},"ManualEvidence":{"manual_path":"app-psql.html#APP-PSQL-META-COMMAND-DD-LC","release":{"channel":"stable","evidence_kind":"English manual and source declarations","label":"18.7","major":"18","manifest":{"major":"18","release":"18.7","source_sha256":"441dfae4280cae3e0425e5f876f80559fb0731c140f1aae22b3e5a54d0411bfd","source_url":"https://ftp.postgresql.org/pub/source/v18.7/postgresql-18.7.tar.bz2"},"ref":"https://ftp.postgresql.org/pub/source/v18.7/postgresql-18.7.tar.bz2","revision":"1b2d62b4845aa46374f2cb680f95d3392322cc8128646992ae4e18d0e7084915","source_sha256":"441dfae4280cae3e0425e5f876f80559fb0731c140f1aae22b3e5a54d0411bfd"},"sources":[{"anchor":"APP-PSQL-META-COMMAND-DD-LC","file":"app-psql.html","label":"18.7 English manual · app-psql.html","sha256":"af50448485df02bdef2b72b8347192ba029c7082b8d0392ecb17db44ad533aaf","url":"/docs/18/app-psql.html#APP-PSQL-META-COMMAND-DD-LC"}]},"MeasuredEvidence":{}},"Text":{"Collection":"psql","Key":"cmd-64-64","SourceDatabase":"center","Version":"18","Locale":"en","Title":"\\dd","Summary":"Shows the descriptions of objects of type constraint , operator class , operator family , rule , and trigger . All other comments may be viewed by the respective backslash commands for those object types.","BodyHTML":"\u003cdiv\u003e\u003cdl\u003e\u003cdt id=\"APP-PSQL-META-COMMAND-DD-LC\"\u003e\u003cspan\u003e\u003ccode\u003e\\dd[Sx] [ \u003ca href=\"/docs/18/app-psql.html#APP-PSQL-PATTERNS\" title=\"Patterns\" rel=\"nofollow\"\u003e\u003cem\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e\u003c/a\u003e ]\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n        Shows the descriptions of objects of type \u003ccode\u003econstraint\u003c/code\u003e,\n        \u003ccode\u003eoperator class\u003c/code\u003e, \u003ccode\u003eoperator family\u003c/code\u003e,\n        \u003ccode\u003erule\u003c/code\u003e, and \u003ccode\u003etrigger\u003c/code\u003e. All\n        other comments may be viewed by the respective backslash commands for\n        those object types.\n        \u003c/p\u003e\u003cp\u003e\u003ccode\u003e\\dd\u003c/code\u003e displays descriptions for objects matching the\n        \u003cem\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e, or of visible\n        objects of the appropriate type if no argument is given.  But in either\n        case, only objects that have a description are listed.\n        By default, only user-created objects are shown;  supply a\n        pattern or the \u003ccode\u003eS\u003c/code\u003e modifier to include system\n        objects.\n        If \u003ccode\u003ex\u003c/code\u003e is appended to the command name, the results\n        are displayed in expanded mode.\n        \u003c/p\u003e\u003cp\u003e\n        Descriptions for objects can be created with the \u003ca href=\"/docs/18/sql-comment.html\" title=\"COMMENT\" rel=\"nofollow\"\u003e\u003ccode\u003eCOMMENT\u003c/code\u003e\u003c/a\u003e\nSQL command.\n       \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","SourceRevision":"1b2d62b4845aa46374f2cb680f95d3392322cc8128646992ae4e18d0e7084915","ContentHash":"05c0898310d84c3d3a0ca07eacf2b8fe3fc927c2debfdceaf4c8eeb6d805d176","Payload":{"description":["Shows the descriptions of objects of type constraint , operator class , operator family , rule , and trigger . All other comments may be viewed by the respective backslash commands for those object types."],"manual_html":"\u003cdiv\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt id=\"APP-PSQL-META-COMMAND-DD-LC\"\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003e\\dd[Sx] [ \u003ca class=\"link\" href=\"/docs/18/app-psql.html#APP-PSQL-PATTERNS\" title=\"Patterns\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e\u003c/a\u003e ]\u003c/code\u003e\u003c/span\u003e \u003c/dt\u003e\u003cdd\u003e\u003cp\u003e\n        Shows the descriptions of objects of type \u003ccode class=\"literal\"\u003econstraint\u003c/code\u003e,\n        \u003ccode class=\"literal\"\u003eoperator class\u003c/code\u003e, \u003ccode class=\"literal\"\u003eoperator family\u003c/code\u003e,\n        \u003ccode class=\"literal\"\u003erule\u003c/code\u003e, and \u003ccode class=\"literal\"\u003etrigger\u003c/code\u003e. All\n        other comments may be viewed by the respective backslash commands for\n        those object types.\n        \u003c/p\u003e\u003cp\u003e\u003ccode class=\"literal\"\u003e\\dd\u003c/code\u003e displays descriptions for objects matching the\n        \u003cem class=\"replaceable\"\u003e\u003ccode\u003epattern\u003c/code\u003e\u003c/em\u003e, or of visible\n        objects of the appropriate type if no argument is given.  But in either\n        case, only objects that have a description are listed.\n        By default, only user-created objects are shown;  supply a\n        pattern or the \u003ccode class=\"literal\"\u003eS\u003c/code\u003e modifier to include system\n        objects.\n        If \u003ccode class=\"literal\"\u003ex\u003c/code\u003e is appended to the command name, the results\n        are displayed in expanded mode.\n        \u003c/p\u003e\u003cp\u003e\n        Descriptions for objects can be created with the \u003ca class=\"link\" href=\"/docs/18/sql-comment.html\" title=\"COMMENT\"\u003e\u003ccode class=\"command\"\u003eCOMMENT\u003c/code\u003e\u003c/a\u003e\nSQL command.\n       \u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","related":[{"label":"psql command-line options and complete manual","url":"/wiki/tool/psql/?v=18"}],"sections":[],"tables":[{"columns":[{"key":"command","label":"Command"},{"key":"modifiers","label":"Documented suffix modifiers"}],"key":"spellings","rows":[{"command":{"text":"\\dd","url":"/wiki/psql/cmd-64-64/?v=18"},"modifiers":"Sx"}],"title":"Spellings in this manual definition"}]}},"RequestedLocale":"en","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":[{"Version":"18","Ordinal":0,"Command":"\\dd","Signature":"\\dd[Sx] [ pattern ]","Modifiers":[{"command":"\\dd","modifiers":"Sx"}]}],"SQLState":null,"Evidence":null}