umbraco-clear-recycle-bin.sql

--deletes in Document
--at this point all associated media files are deleted
delete from umbracoDomains where id in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsDocument where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
 
--deletes in Content
delete from cmsPropertyData where contentNodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsPreviewXml where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsContentVersion where ContentId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsContentXml where NodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
 
--deletes in CMSNode
delete from umbracoRelation where parentId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoRelation where childId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsTask where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoUser2NodeNotify where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsTagRelationship where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoUser2NodePermission where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsContent where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoNode where path like '%-20%' and id!=-20;

Updated for Umbraco 11.4.2 (to include VersionCulture tables):

--deletes in Document
--at this point all associated media files are deleted
delete from umbracoDomain where id in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoDocument where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoDocumentVersion where id in (select id from umbracoContentVersion where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20));
delete from umbracoDocumentCultureVariation where nodeid in (select id from umbracoNode where path like '%-20%' and id!=-20);

--deletes in Content
delete from umbracoPropertyData where versionId in (select id from umbracoContentVersion where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20));
delete from umbracoContentVersionCultureVariation where versionid in (select id from umbracoContentVersion where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20));
delete from umbracoContentVersion where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsContentNu where NodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);

--deletes in CMSNode
delete from umbracoRelation where parentId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoRelation where childId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoUser2NodeNotify where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from cmsTagRelationship where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoUserGroup2NodePermission where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoContent where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20);
delete from umbracoContentSchedule where nodeId in (select id from umbracoNode where path like '%-20%' and id!=-20)
delete from umbracoRedirectUrl where contentKey in (select uniqueId from umbracoNode where path like '%-20%' and id!=-20)
delete from umbracoNode where path like '%-20%' and id!=-20;