{"Entry":{"collection":"sql","key":"drop-transform","name":"DROP TRANSFORM","aliases":["droptransform"],"metadata":{"aliases":["droptransform"],"changed_in":["9.6"],"changes":[{"from":"9.4","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":[],"removed":[]},"status":"added","synopsis":null,"to":"9.5"},{"from":"9.5","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":{"added":["DROP TRANSFORM [ IF EXISTS ] FOR type_name LANGUAGE lang_name [ CASCADE | RESTRICT ]"],"removed":[]},"to":"9.6"},{"from":"11","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":null,"to":"12"},{"from":"14","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["examples"],"removed":[]},"status":"changed","synopsis":null,"to":"15"},{"from":"16","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":null,"to":"17"},{"from":"18","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":null,"to":"19"}],"content_hash":"b3e765b26cdcf6a3faba7483184d49d3a0848848193cca4e9468c9909743b70e","editorial":{},"first_version":"9.5","group":"routine","imported_at":"2026-09-30T17:43:37.334484+08:00","last_version":"20","name":"DROP TRANSFORM","object":"TRANSFORM","position":2017,"present_in":["9.5","9.6","10","11","12","13","14","15","16","17","18","19","20"],"purpose":"remove a transform","purpose_zh":"","related":["create-transform"],"slug":"drop-transform","source_rev":"a709ab85","synopsis":"DROP TRANSFORM [ IF EXISTS ] FOR type_name LANGUAGE lang_name [ CASCADE | RESTRICT ]","verb":"DROP"}},"Definition":{"Collection":"sql","Key":"drop-transform","SourceDatabase":"center","Version":"18","SourceTable":"sqlcmd","SourceKey":"drop-transform","SourceRevision":"a709ab85","Facts":{"anchor":"SQL-DROPTRANSFORM","file":"sql-droptransform.html","lang":"en","name":"DROP TRANSFORM","purpose":"remove a transform","purpose_zh":"","related":["create-transform"],"sections":[{"html":"\u003cp\u003e\u003ccode class=\"command\"\u003eDROP TRANSFORM\u003c/code\u003e removes a previously defined transform.\u003c/p\u003e\u003cp\u003eTo be able to drop a transform, you must own the type and the language. These are the same privileges that are required to create a transform.\u003c/p\u003e","key":"description","title":"Description"},{"html":"\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eIF EXISTS\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eDo not throw an error if the transform does not exist. A notice is issued in this case.\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003etype_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eThe name of the data type of the transform.\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003elang_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eThe name of the language of the transform.\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eCASCADE\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eAutomatically drop objects that depend on the transform, and in turn all objects that depend on those objects (see \u003ca href=\"/docs/18/ddl-depend.html\" title=\"5.15. Dependency Tracking\"\u003eSection 5.15\u003c/a\u003e).\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eRESTRICT\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eRefuse to drop the transform if any objects depend on it. This is the default.\u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","key":"parameters","title":"Parameters"},{"html":"\u003cp\u003eTo drop the transform for type \u003ccode class=\"type\"\u003ehstore\u003c/code\u003e and language \u003ccode class=\"literal\"\u003eplpython3u\u003c/code\u003e:\u003c/p\u003e\u003cpre class=\"programlisting\"\u003eDROP TRANSFORM FOR hstore LANGUAGE plpython3u;\n\u003c/pre\u003e","key":"examples","title":"Examples"},{"html":"\u003cp\u003eThis form of \u003ccode class=\"command\"\u003eDROP TRANSFORM\u003c/code\u003e is a \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e extension. See \u003ca href=\"/docs/18/sql-createtransform.html\" title=\"CREATE TRANSFORM\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e for details.\u003c/p\u003e","key":"compatibility","title":"Compatibility"},{"html":"\u003cspan class=\"simplelist\"\u003e\u003ca href=\"/wiki/sql/create-transform/?v=18\" title=\"CREATE TRANSFORM\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e","key":"see_also","title":"See Also"}],"sections_same_as":"","slug":"18","synopsis_html":"DROP TRANSFORM [ IF EXISTS ] FOR \u003cem class=\"replaceable\"\u003e\u003ccode\u003etype_name\u003c/code\u003e\u003c/em\u003e LANGUAGE \u003cem class=\"replaceable\"\u003e\u003ccode\u003elang_name\u003c/code\u003e\u003c/em\u003e [ CASCADE | RESTRICT ]","synopsis_text":"DROP TRANSFORM [ IF EXISTS ] FOR type_name LANGUAGE lang_name [ CASCADE | RESTRICT ]"},"ManualEvidence":{},"MeasuredEvidence":{}},"Text":{"Collection":"sql","Key":"drop-transform","SourceDatabase":"pgweb","Version":"18","Locale":"zh-Hans","Title":"DROP TRANSFORM","Summary":"移除一个转换","BodyHTML":"\u003cpre\u003eDROP TRANSFORM [ IF EXISTS ] FOR type_name LANGUAGE lang_name [ CASCADE | RESTRICT ]\u003c/pre\u003e\u003csection\u003e\u003ch2\u003e描述\u003c/h2\u003e\u003cp\u003e\u003ccode\u003eDROP TRANSFORM\u003c/code\u003e移除一个先前定义的转换。\u003c/p\u003e\u003cp\u003e要能够删除一种转换，你必须拥有该类型和该语言。这与创建一种转换所需的权限相同。\u003c/p\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e参数\u003c/h2\u003e\u003cdiv\u003e\u003cdl\u003e\u003cdt\u003e\u003cspan\u003e\u003ccode\u003eIF EXISTS\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e如果该转换不存在，则不要抛出错误。这种情况下会发出一个提示。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan\u003e\u003cem\u003e\u003ccode\u003etype_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e该转换的数据类型名称。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan\u003e\u003cem\u003e\u003ccode\u003elang_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e该转换所用语言的名称。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan\u003e\u003ccode\u003eCASCADE\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e自动删除依赖于该转换的对象，以及进一步依赖于这些对象的所有对象（参见\u003ca href=\"/docs/18/ddl-depend.html\" rel=\"nofollow\"\u003e第 5.15 节\u003c/a\u003e）。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan\u003e\u003ccode\u003eRESTRICT\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e如果有任何对象依赖于该转换，则拒绝删除它。这是默认值。\u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e示例\u003c/h2\u003e\u003cp\u003e要删除类型\u003ccode\u003ehstore\u003c/code\u003e和语言\u003ccode\u003eplpython3u\u003c/code\u003e的转换：\u003c/p\u003e\u003cpre\u003eDROP TRANSFORM FOR hstore LANGUAGE plpython3u;\n\u003c/pre\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e兼容性\u003c/h2\u003e\u003cp\u003e这种形式的\u003ccode\u003eDROP TRANSFORM\u003c/code\u003e是 \u003cspan\u003ePostgreSQL\u003c/span\u003e的一种扩展。详见\u003ca href=\"/docs/18/sql-createtransform.html\" title=\"CREATE TRANSFORM\" rel=\"nofollow\"\u003e\u003cspan\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e。\u003c/p\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e另见\u003c/h2\u003e\u003cspan\u003e\u003ca href=\"/wiki/sql/create-transform/?v=18\" title=\"CREATE TRANSFORM\" rel=\"nofollow\"\u003e\u003cspan\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e\u003c/section\u003e","SourceRevision":"1b5ca64c","ContentHash":"1139ded00eb113264a41e79ea7c37369553e6a639cdd29a0d99b0ab2d1789c64","Payload":{"purpose_zh":"移除一个转换","sections":[{"html":"\u003cp\u003e\u003ccode class=\"command\"\u003eDROP TRANSFORM\u003c/code\u003e移除一个先前定义的转换。\u003c/p\u003e\u003cp\u003e要能够删除一种转换，你必须拥有该类型和该语言。这与创建一种转换所需的权限相同。\u003c/p\u003e","key":"description","title":"描述"},{"html":"\u003cdiv class=\"variablelist\"\u003e\u003cdl class=\"variablelist\"\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eIF EXISTS\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e如果该转换不存在，则不要抛出错误。这种情况下会发出一个提示。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003etype_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e该转换的数据类型名称。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003cem class=\"replaceable\"\u003e\u003ccode\u003elang_name\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e该转换所用语言的名称。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eCASCADE\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e自动删除依赖于该转换的对象，以及进一步依赖于这些对象的所有对象（参见\u003ca href=\"/docs/18/ddl-depend.html\" title=\"5.15. 依赖跟踪\"\u003e第 5.15 节\u003c/a\u003e）。\u003c/p\u003e\u003c/dd\u003e\u003cdt\u003e\u003cspan class=\"term\"\u003e\u003ccode class=\"literal\"\u003eRESTRICT\u003c/code\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e如果有任何对象依赖于该转换，则拒绝删除它。这是默认值。\u003c/p\u003e\u003c/dd\u003e\u003c/dl\u003e\u003c/div\u003e","key":"parameters","title":"参数"},{"html":"\u003cp\u003e要删除类型\u003ccode class=\"type\"\u003ehstore\u003c/code\u003e和语言\u003ccode class=\"literal\"\u003eplpython3u\u003c/code\u003e的转换：\u003c/p\u003e\u003cpre class=\"programlisting\"\u003eDROP TRANSFORM FOR hstore LANGUAGE plpython3u;\n\u003c/pre\u003e","key":"examples","title":"示例"},{"html":"\u003cp\u003e这种形式的\u003ccode class=\"command\"\u003eDROP TRANSFORM\u003c/code\u003e是 \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e的一种扩展。详见\u003ca href=\"/docs/18/sql-createtransform.html\" title=\"CREATE TRANSFORM\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e。\u003c/p\u003e","key":"compatibility","title":"兼容性"},{"html":"\u003cspan class=\"simplelist\"\u003e\u003ca href=\"/wiki/sql/create-transform/?v=18\" title=\"CREATE TRANSFORM\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE TRANSFORM\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e","key":"see_also","title":"另见"}],"sections_same_as":"","synopsis_html":"DROP TRANSFORM [ IF EXISTS ] FOR \u003cem class=\"replaceable\"\u003e\u003ccode\u003etype_name\u003c/code\u003e\u003c/em\u003e LANGUAGE \u003cem class=\"replaceable\"\u003e\u003ccode\u003elang_name\u003c/code\u003e\u003c/em\u003e [ CASCADE | RESTRICT ]","synopsis_text":"DROP TRANSFORM [ IF EXISTS ] FOR type_name LANGUAGE lang_name [ CASCADE | RESTRICT ]"}},"RequestedLocale":"zh-Hans","Fallback":false,"Versions":["10","11","12","13","14","15","16","17","18","19","20","9.5","9.6"],"Locales":["en","zh-Hans"],"Signatures":null,"Spellings":null,"SQLState":null,"Evidence":null}