appview: add utilities to delete records by rkey

did+rkey can uniquely identify a row for any data record.

appview/db/follow.go

···
 	return err
 }
 
+// Remove a follow
+func DeleteFollowByRkey(e Execer, userDid, rkey string) error {
+	_, err := e.Exec(`delete from follows where user_did = ? and rkey = ?`, userDid, rkey)
+	return err
+}
+
 func GetFollowerFollowing(e Execer, did string) (int, int, error) {
 	followers, following := 0, 0
 	err := e.QueryRow(

appview/db/pubkeys.go

···
 	return err
 }
 
-func RemovePublicKey(e Execer, did, name, key string) error {
+func DeletePublicKey(e Execer, did, name, key string) error {
 	_, err := e.Exec(`
 		delete from public_keys 
 		where did = ? and name = ? and key = ?`,
 		did, name, key)
+	return err
+}
+
+func DeletePublicKeyByRkey(e Execer, did, rkey string) error {
+	_, err := e.Exec(`
+		delete or ignore from public_keys 
+		where did = ? and name = ? and rkey = ?`,
+		did, rkey)
 	return err
 }
 

appview/db/star.go

···
 	return err
 }
 
+// Remove a star
+func DeleteStarByRkey(e Execer, starredByDid string, rkey string) error {
+	_, err := e.Exec(`delete or ignore from stars where starred_by_did = ? and rkey = ?`, starredByDid, rkey)
+	return err
+}
+
 func GetStarCount(e Execer, repoAt syntax.ATURI) (int, error) {
 	stars := 0
 	err := e.QueryRow(

appview/settings/settings.go

···
 
 		client, _ := s.Auth.AuthorizedClient(r)
 
-		if err := db.RemovePublicKey(s.Db, did, name, key); err != nil {
+		if err := db.DeletePublicKey(s.Db, did, name, key); err != nil {
 			log.Printf("removing public key: %s", err)
 			s.Pages.Notice(w, "settings-keys", "Failed to remove public key.")
 			return

appview/state/follow.go

···
 			return
 		}
 
-		err = db.DeleteFollow(s.db, currentUser.Did, subjectIdent.DID.String())
+		err = db.DeleteFollowByRkey(s.db, currentUser.Did, follow.Rkey)
 		if err != nil {
 			log.Println("failed to delete follow from DB")
 			// this is not an issue, the firehose event might have already done this

appview/state/star.go

···
 			return
 		}
 
-		err = db.DeleteStar(s.db, currentUser.Did, subjectUri)
+		err = db.DeleteStarByRkey(s.db, currentUser.Did, star.Rkey)
 		if err != nil {
 			log.Println("failed to delete star from DB")
 			// this is not an issue, the firehose event might have already done this