--> 测试数据：[tb]
IF OBJECT_ID('[tb]') IS NOT NULL DROP TABLE [tb]
GO 
CREATE TABLE [tb]([f_ReadDate] DATETIME,[f_ConsumerName] VARCHAR(10))
INSERT [tb]
SELECT '2012-9-29 8:31:03','lanyang' UNION ALL
SELECT '2012-9-29 8:31:04','lanyang' UNION ALL
SELECT '2012-9-29 8:28:23','wangxiao' UNION ALL
SELECT '2012-9-29 8:27:12','chenchunli' UNION ALL
SELECT '2012-9-29 8:27:01','chenchunli' UNION ALL
SELECT '2012-9-29 8:26:33','liuzg' UNION ALL
SELECT '2012-9-29 8:25:22','zhouar' UNION ALL
SELECT '2012-9-29 8:25:21','tangyc' UNION ALL
SELECT '2012-9-29 8:31:12','zhangsh' UNION ALL
SELECT '2012-9-29 8:21:33','yangmei' UNION ALL
SELECT '2012-9-29 8:21:45','yangmei' UNION ALL
SELECT '2012-9-29 8:21:23','jianghy' UNION ALL
SELECT '2012-9-29 8:21:15','jianghy' UNION ALL
SELECT '2012-9-29 8:09:12','liuyi' UNION ALL
SELECT '2012-9-29 8:09:22','zhangsf' UNION ALL
SELECT '2012-9-28 17:44:15','tangyc' UNION ALL
SELECT '2012-9-28 17:43:15','tangyc' UNION ALL
SELECT '2012-9-28 17:41:23','liuyi' UNION ALL
SELECT '2012-9-28 17:40:14','jianghy'
--------------开始查询--------------------------

SELECT  [f_ReadDate] , [f_ConsumerName] , 状态
FROM    (
         SELECT * , 状态 = CASE WHEN CONVERT(VARCHAR(8) , [f_ReadDate] , 108) > '08:30:59' THEN '迟到'
                              ELSE '正常上班'
                         END , 1 AS 上下班
         FROM   [tb] AS t
         WHERE  NOT EXISTS ( SELECT 1
                             FROM   tb
                             WHERE  CONVERT(VARCHAR(8) , [f_ConsumerName] , 112) = CONVERT(VARCHAR(8) , t.[f_ConsumerName] , 112)
                                    AND [f_ReadDate] > t.[f_ReadDate]
                                    AND CONVERT(VARCHAR(8) , [f_ReadDate] , 108) < '12:00:00' )
                AND CONVERT(VARCHAR(8) , [f_ReadDate] , 108) < '12:00:00'
         UNION ALL
         SELECT * , 状态 = CASE WHEN CONVERT(VARCHAR(8) , [f_ReadDate] , 108) < '12:00:00' THEN '早退'
                              ELSE '正常下班'
                         END , 2 AS 上下班
         FROM   [tb] AS t
         WHERE  NOT EXISTS ( SELECT 1
                             FROM   tb
                             WHERE  CONVERT(VARCHAR(8) , [f_ConsumerName] , 112) = CONVERT(VARCHAR(8) , t.[f_ConsumerName] , 112)
                                    AND [f_ReadDate] > t.[f_ReadDate]
                                    AND CONVERT(VARCHAR(8) , [f_ReadDate] , 108) > '13:00:00' )
                AND CONVERT(VARCHAR(8) , [f_ReadDate] , 108) > '13:00:00'
        ) AS t
ORDER BY [f_ConsumerName] , 上下班                 
----------------结果----------------------------
/* 
f_ReadDate    f_ConsumerName    状态
2012-09-29 08:27:12.000    chenchunli    正常上班
2012-09-29 08:21:23.000    jianghy    正常上班
2012-09-28 17:40:14.000    jianghy    正常下班
2012-09-29 08:31:04.000    lanyang    迟到
2012-09-29 08:09:12.000    liuyi    正常上班
2012-09-28 17:41:23.000    liuyi    正常下班
2012-09-29 08:26:33.000    liuzg    正常上班
2012-09-29 08:25:21.000    tangyc    正常上班
2012-09-28 17:44:15.000    tangyc    正常下班
2012-09-29 08:28:23.000    wangxiao    正常上