{"Entry":{"collection":"sql","key":"drop-collation","name":"DROP COLLATION","aliases":["dropcollation"],"metadata":{"aliases":["dropcollation"],"changed_in":[],"changes":[{"from":"9.0","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":[],"removed":[]},"status":"added","synopsis":null,"to":"9.1"},{"from":"9.5","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":null,"to":"9.6"},{"from":"11","purpose_changed":false,"renamed":null,"sections":{"added":[],"changed":["parameters"],"removed":[]},"status":"changed","synopsis":null,"to":"12"},{"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":"b8656cff600f8285e92fbebe772ccbdadb3251e24ebda7d11c054d71970d4634","editorial":{},"first_version":"9.1","group":"type","imported_at":"2026-09-30T17:43:37.412704+08:00","last_version":"20","name":"DROP COLLATION","object":"COLLATION","position":3004,"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"],"purpose":"remove a collation","purpose_zh":"","related":["alter-collation","create-collation"],"slug":"drop-collation","source_rev":"a709ab85","synopsis":"DROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]","verb":"DROP"}},"Definition":{"Collection":"sql","Key":"drop-collation","SourceDatabase":"center","Version":"18","SourceTable":"sqlcmd","SourceKey":"drop-collation","SourceRevision":"a709ab85","Facts":{"anchor":"SQL-DROPCOLLATION","file":"sql-dropcollation.html","lang":"en","name":"DROP COLLATION","purpose":"remove a collation","purpose_zh":"","related":["alter-collation","create-collation"],"sections":[{"html":"\u003cp\u003e\u003ccode class=\"command\"\u003eDROP COLLATION\u003c/code\u003e removes a previously defined collation. To be able to drop a collation, you must own the collation.\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 collation 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\u003ename\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003eThe name of the collation. The collation name can be schema-qualified.\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 collation, 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 collation 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 collation named \u003ccode class=\"literal\"\u003egerman\u003c/code\u003e:\u003c/p\u003e\u003cpre class=\"programlisting\"\u003eDROP COLLATION german;\n\u003c/pre\u003e","key":"examples","title":"Examples"},{"html":"\u003cp\u003eThe \u003ccode class=\"command\"\u003eDROP COLLATION\u003c/code\u003e command conforms to the \u003cacronym\u003eSQL\u003c/acronym\u003e standard, apart from the \u003ccode class=\"literal\"\u003eIF EXISTS\u003c/code\u003e option, which is a \u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e extension.\u003c/p\u003e","key":"compatibility","title":"Compatibility"},{"html":"\u003cspan class=\"simplelist\"\u003e\u003ca href=\"/wiki/sql/alter-collation/?v=18\" title=\"ALTER COLLATION\"\u003e\u003cspan class=\"refentrytitle\"\u003eALTER COLLATION\u003c/span\u003e\u003c/a\u003e, \u003ca href=\"/wiki/sql/create-collation/?v=18\" title=\"CREATE COLLATION\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE COLLATION\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e","key":"see_also","title":"See Also"}],"sections_same_as":"","slug":"18","synopsis_html":"DROP COLLATION [ IF EXISTS ] \u003cem class=\"replaceable\"\u003e\u003ccode\u003ename\u003c/code\u003e\u003c/em\u003e [ CASCADE | RESTRICT ]","synopsis_text":"DROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]"},"ManualEvidence":{},"MeasuredEvidence":{}},"Text":{"Collection":"sql","Key":"drop-collation","SourceDatabase":"pgweb","Version":"18","Locale":"zh-Hans","Title":"DROP COLLATION","Summary":"删除一个排序规则","BodyHTML":"\u003cpre\u003eDROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]\u003c/pre\u003e\u003csection\u003e\u003ch2\u003e描述\u003c/h2\u003e\u003cp\u003e\u003ccode\u003eDROP COLLATION\u003c/code\u003e删除一个先前定义的排序规则。要删除一个排序规则，你必须拥有该排序规则。\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如果该排序规则不存在，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\u003ename\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e排序规则的名称。该名称可以使用模式限定。\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自动删除依赖于该排序规则的对象，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排序规则，则拒绝删除该排序规则。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删除名为\u003ccode\u003egerman\u003c/code\u003e的排序规则：\u003c/p\u003e\u003cpre\u003eDROP COLLATION german;\n\u003c/pre\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e兼容性\u003c/h2\u003e\u003cp\u003e\u003ccode\u003eDROP COLLATION\u003c/code\u003e命令符合\u003cacronym\u003eSQL\u003c/acronym\u003e标准，但\u003ccode\u003eIF EXISTS\u003c/code\u003e选项是\u003cspan\u003ePostgreSQL\u003c/span\u003e扩展。\u003c/p\u003e\u003c/section\u003e\u003csection\u003e\u003ch2\u003e另见\u003c/h2\u003e\u003cspan\u003e\u003ca href=\"/wiki/sql/alter-collation/?v=18\" title=\"ALTER COLLATION\" rel=\"nofollow\"\u003e\u003cspan\u003eALTER COLLATION\u003c/span\u003e\u003c/a\u003e, \u003ca href=\"/wiki/sql/create-collation/?v=18\" title=\"CREATE COLLATION\" rel=\"nofollow\"\u003e\u003cspan\u003eCREATE COLLATION\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e\u003c/section\u003e","SourceRevision":"1b5ca64c","ContentHash":"aaf2aae8251f7cfe0c6f66ba89b7e43f25ff7269931c624f7031d3c428756c88","Payload":{"purpose_zh":"删除一个排序规则","sections":[{"html":"\u003cp\u003e\u003ccode class=\"command\"\u003eDROP COLLATION\u003c/code\u003e删除一个先前定义的排序规则。要删除一个排序规则，你必须拥有该排序规则。\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如果该排序规则不存在，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\u003ename\u003c/code\u003e\u003c/em\u003e\u003c/span\u003e\u003c/dt\u003e\u003cdd\u003e\u003cp\u003e排序规则的名称。该名称可以使用模式限定。\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自动删除依赖于该排序规则的对象，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排序规则，则拒绝删除该排序规则。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删除名为\u003ccode class=\"literal\"\u003egerman\u003c/code\u003e的排序规则：\u003c/p\u003e\u003cpre class=\"programlisting\"\u003eDROP COLLATION german;\n\u003c/pre\u003e","key":"examples","title":"示例"},{"html":"\u003cp\u003e\u003ccode class=\"command\"\u003eDROP COLLATION\u003c/code\u003e命令符合\u003cacronym\u003eSQL\u003c/acronym\u003e标准，但\u003ccode class=\"literal\"\u003eIF EXISTS\u003c/code\u003e选项是\u003cspan class=\"productname\"\u003ePostgreSQL\u003c/span\u003e扩展。\u003c/p\u003e","key":"compatibility","title":"兼容性"},{"html":"\u003cspan class=\"simplelist\"\u003e\u003ca href=\"/wiki/sql/alter-collation/?v=18\" title=\"ALTER COLLATION\"\u003e\u003cspan class=\"refentrytitle\"\u003eALTER COLLATION\u003c/span\u003e\u003c/a\u003e, \u003ca href=\"/wiki/sql/create-collation/?v=18\" title=\"CREATE COLLATION\"\u003e\u003cspan class=\"refentrytitle\"\u003eCREATE COLLATION\u003c/span\u003e\u003c/a\u003e\u003c/span\u003e","key":"see_also","title":"另见"}],"sections_same_as":"","synopsis_html":"DROP COLLATION [ IF EXISTS ] \u003cem class=\"replaceable\"\u003e\u003ccode\u003ename\u003c/code\u003e\u003c/em\u003e [ CASCADE | RESTRICT ]","synopsis_text":"DROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]"}},"RequestedLocale":"zh-Hans","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":null,"Spellings":null,"SQLState":null,"Evidence":null}