SQL中CONVERT转化函数的用法

格式:
CONVERT(data_type,expression[,style])

说明:
此样式一般在时间类型(datetime,smalldatetime)与字符串类型(nchar,nvarchar,char,varchar)
相互转换的时候才用到.

例子:
SELECT CONVERT(varchar(30),getdate(),101) now
结果为:
now
---------------------------------------
|09/15/2001

===================================================================

style数字在转换时间时的含义如下:

------------------------------------------------------------------------------------------------------------
Style(2位表示年份)   |  Style(4位表示年份)   |   输入输出格式                                    
------------------------------------------------------------------------------------------------------------
0                               | 100                           |   mon dd yyyy hh:miAM(或PM)              
------------------------------------------------------------------------------------------------------------
1                               |  101   美国                |   mm/dd/yy                                       
------------------------------------------------------------------------------------------------------------
2                               |  102    ANSI               |   yy-mm-dd                                        
------------------------------------------------------------------------------------------------------------
3                               |  103    英法                |   dd/mm/yy                                       
------------------------------------------------------------------------------------------------------------
4                               |  104    德国                |   dd.mm.yy                                        
------------------------------------------------------------------------------------------------------------
5                               |  105    意大利             |   dd-mm-yy                                        
------------------------------------------------------------------------------------------------------------
6                               |  106                            |   dd mon yy                                        
------------------------------------------------------------------------------------------------------------
7                               |  107                            |   mon dd,yy                                        
------------------------------------------------------------------------------------------------------------
8                               |  108                            |   hh:mm:ss                                         
------------------------------------------------------------------------------------------------------------
9                               |  109                            |   mon dd yyyy hh:mi:ss:mmmmAM(或PM)
------------------------------------------------------------------------------------------------------------
10                             |  110    美国                 |   mm-dd-yy                                         
------------------------------------------------------------------------------------------------------------
11                             |  111    日本                 |   yy/mm/dd                                        
------------------------------------------------------------------------------------------------------------
12                             |  112    ISO                  |   yymmdd                                           
------------------------------------------------------------------------------------------------------------
13                             |  113     欧洲默认值     |   dd mon yyyy hh:mi:ss:mmm(24小时制)  
------------------------------------------------------------------------------------------------------------
14                             |  114                            |   hh:mi:ss:mmm(24小时制)                    
------------------------------------------------------------------------------------------------------------
20                             |  120     ODBC 规范     |    yyyy-mm-dd hh:mi:ss(24小时制)         
------------------------------------------------------------------------------------------------------------
21                             |   121                           |    yyyy-mm-dd hh:mi:ss:mmm(24小时制) 
------------------------------------------------------------------------------------------------------------

语句及查询结果：
SELECT CONVERT(varchar(100), GETDATE(), 0): 05 16 2006 10:57AM
SELECT CONVERT(varchar(100), GETDATE(), 1): 05/16/06
SELECT CONVERT(varchar(100), GETDATE(), 2): 06.05.16
SELECT CONVERT(varchar(100), GETDATE(), 3): 16/05/06
SELECT CONVERT(varchar(100), GETDATE(), 4): 16.05.06
SELECT CONVERT(varchar(100), GETDATE(), 5): 16-05-06
SELECT CONVERT(varchar(100), GETDATE(), 6): 16 05 06
SELECT CONVERT(varchar(100), GETDATE(), 7): 05 16, 06
SELECT CONVERT(varchar(100), GETDATE(), 8): 10:57:46
SELECT CONVERT(varchar(100), GETDATE(), 9): 05 16 2006 10:57:46:827AM
SELECT CONVERT(varchar(100), GETDATE(), 10): 05-16-06
SELECT CONVERT(varchar(100), GETDATE(), 11): 06/05/16
SELECT CONVERT(varchar(100), GETDATE(), 12): 060516
SELECT CONVERT(varchar(100), GETDATE(), 13): 16 05 2006 10:57:46:937
SELECT CONVERT(varchar(100), GETDATE(), 14): 10:57:46:967
SELECT CONVERT(varchar(100), GETDATE(), 20): 2006-05-16 10:57:47
SELECT CONVERT(varchar(100), GETDATE(), 21): 2006-05-16 10:57:47.157
SELECT CONVERT(varchar(100), GETDATE(), 22): 05/16/06 10:57:47 AM
SELECT CONVERT(varchar(100), GETDATE(), 23): 2006-05-16
SELECT CONVERT(varchar(100), GETDATE(), 24): 10:57:47
SELECT CONVERT(varchar(100), GETDATE(), 25): 2006-05-16 10:57:47.250
SELECT CONVERT(varchar(100), GETDATE(), 100): 05 16 2006 10:57AM
SELECT CONVERT(varchar(100), GETDATE(), 101): 05/16/2006
SELECT CONVERT(varchar(100), GETDATE(), 102): 2006.05.16
SELECT CONVERT(varchar(100), GETDATE(), 103): 16/05/2006
SELECT CONVERT(varchar(100), GETDATE(), 104): 16.05.2006
SELECT CONVERT(varchar(100), GETDATE(), 105): 16-05-2006
SELECT CONVERT(varchar(100), GETDATE(), 106): 16 05 2006
SELECT CONVERT(varchar(100), GETDATE(), 107): 05 16, 2006
SELECT CONVERT(varchar(100), GETDATE(), 108): 10:57:49
SELECT CONVERT(varchar(100), GETDATE(), 109): 05 16 2006 10:57:49:437AM
SELECT CONVERT(varchar(100), GETDATE(), 110): 05-16-2006
SELECT CONVERT(varchar(100), GETDATE(), 111): 2006/05/16
SELECT CONVERT(varchar(100), GETDATE(), 112): 20060516
SELECT CONVERT(varchar(100), GETDATE(), 113): 16 05 2006 10:57:49:513
SELECT CONVERT(varchar(100), GETDATE(), 114): 10:57:49:547
SELECT CONVERT(varchar(100), GETDATE(), 120): 2006-05-16 10:57:49
SELECT CONVERT(varchar(100), GETDATE(), 121): 2006-05-16 10:57:49:000

原文：http://www.cnblogs.com/xionglee/articles/1444916.html