使用restore database preview语句，出现以下报错：
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01005: syntax error: found "identifier": expecting one of: "archivelog, cha
nnel, check, controlfile, clone, database, datafile, device, from, force, high,
(, parms, ;, skip, spfile, standby, tablespace, until, validate"
RMAN-01008: the bad identifier was: preview
RMAN-01007: at line 1 column 18 file: standard input

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01005: syntax error: found ";": expecting one of: "allocate, alter, backup,
beginline, blockrecover, catalog, change, connect, copy, create, crosscheck, co
nfigure, duplicate, debug, delete, drop, exit, endinline, host, {, library, list
, mount, open, print, quit, recover, register, release, replace, report, renorma
lize, reset, restore, resync, rman, run, rpctest, set, setlimit, sql, spool, sta
rtup, shutdown, send, show, test, upgrade, validate"
RMAN-01007: at line 1 column 25 file: standard input
请各位大神指点一下

使用restore database preview语句，出现以下报错：
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01005: syntax error: found "identifier": expecting one of: "archivelog, cha
nnel, check, controlfile, clone, database, datafile, device, from, force, high,
(, parms, ;, skip, spfile, standby, tablespace, until, validate"
RMAN-01008: the bad identifier was: preview
RMAN-01007: at line 1 column 18 file: standard input

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01005: syntax error: found ";": expecting one of: "allocate, alter, backup,
beginline, blockrecover, catalog, change, connect, copy, create, crosscheck, co
nfigure, duplicate, debug, delete, drop, exit, endinline, host, {, library, list
, mount, open, print, quit, recover, register, release, replace, report, renorma
lize, reset, restore, resync, rman, run, rpctest, set, setlimit, sql, spool, sta
rtup, shutdown, send, show, test, upgrade, validate"
RMAN-01007: at line 1 column 25 file: standard input
请各位大神指点一下