你sql写的有误吧，应该是ROW_NUMBER() OVER (partition by xx ORDER BY xx DESC) ,参考示例如下：

DROP TABLE IF EXISTS "SYSDBA"."ORDERINFO";

CREATE TABLE "SYSDBA"."ORDERINFO"
(
"ID" INT IDENTITY(1, 1) NOT NULL,
"USERID" NVARCHAR(50 CHAR) NOT NULL,
"TOTALPRICE" FLOAT NOT NULL,
"ORDERTIME" DATETIME(6) NOT NULL,
NOT CLUSTER PRIMARY KEY("ID")) STORAGE(ON "MAIN", CLUSTERBTR) ;

INSERT INTO ORDERINFO
           (USERID
           ,TOTALPRICE
           ,ORDERTIME)
     VALUES
           ('1', 111, CAST('2011-01-01' AS DATETIME)),
           ('1', 112, CAST('2011-01-02' AS DATETIME)),
           ('3', 311, CAST('2013-01-01' AS DATETIME)),
           ('3', 312, CAST('2013-01-02' AS DATETIME)),
           ('2', 211, CAST('2012-01-01' AS DATETIME)),
           ('2', 212, CAST('2012-01-02' AS DATETIME)),
           ('1', 113, CAST('2011-01-03' AS DATETIME)),
           ('2', 213, CAST('2012-01-03' AS DATETIME)),
           ('3', 313, CAST('2013-01-03' AS DATETIME));
COMMIT;       
           
SELECT * FROM ORDERINFO;
SELECT ID,USERID,TOTALPRICE,ORDERTIME,ROW_NUMBER() OVER (partition by USERID ORDER BY ORDERTIME DESC) AS ROWINDEX FROM ORDERINFO;