SELECT FLOOR([quantity]) FROM [tb]

------解决方案--------------------


  select distinct 列名  from 表名  

  select count(*)  from 表名

看看记录数是否相等

------解决方案--------------------
select cast([quantity] as int) from 表名

------解决方案--------------------
SQL code
--> 测试数据：[tb]
IF OBJECT_ID('[tb]') IS NOT NULL DROP TABLE [tb]
GO 
CREATE TABLE [tb]([quantity] NUMERIC(9,3))
INSERT [tb]
SELECT 0.8 UNION ALL
SELECT 1.8 UNION ALL
SELECT 30.259 UNION ALL
SELECT 0.003 UNION ALL
SELECT 122323
--------------开始查询--------------------------
 SELECT b.[quantity],CASE WHEN b.cnt>1 THEN 'F' ELSE 'T' END 
 FROM [tb] a 
 LEFT JOIN(
 SELECT FLOOR([quantity]) AS [quantity],COUNT(*) AS cnt FROM [tb] GROUP BY FLOOR([quantity]) 
 ) b ON FLOOR(a.[quantity]) =b.[quantity]
 
----------------结果----------------------------
/* 
quantity                                
--------------------------------------- ----
0                                       F
1                                       T
30                                      T
0                                       F
122323                                  T

(5 行受影响)


*/

------解决方案--------------------
SQL code

SELECT CASE COUNT(1) WHEN 1 THEN 'TRUE'
       ELSE 'FALSE' END AS count 
FROM tba
GROUP BY TNT