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 or 100 | mon dd yyyy hh:miAM(或PM) ------------------------------------------------------------------------------------------------- 1 | 101 | mm/dd/yy ------------------------------------------------------------------------------------------------- 2 | 102 | yy-mm-dd ------------------------------------------------------------------------------------------------- 3 | 103 | dd/mm/yy ------------------------------------------------------------------------------------------------- 4 | 104 | dd-mm-yy ------------------------------------------------------------------------------------------------- 5 | 105 | dd-mm-yy ------------------------------------------------------------------------------------------------- 6 | 106 | dd mon yy ------------------------------------------------------------------------------------------------- 7 | 107 | mon dd,yy ------------------------------------------------------------------------------------------------- 8 | 108 | hh:mm:ss ------------------------------------------------------------------------------------------------- - | 9 or 109 | mon dd yyyy hh:mi:ss:mmmmAM(或PM) ------------------------------------------------------------------------------------------------- 10 | 110 | mm-dd-yy ------------------------------------------------------------------------------------------------- 11 | 111 | yy/mm/dd ------------------------------------------------------------------------------------------------- 12 | 112 | yymmdd ------------------------------------------------------------------------------------------------- - | 13 or 113 | dd mon yyyy hh:mi:ss:mmm(24小时制) ------------------------------------------------------------------------------------------------- 14 | 114 | hh:mi:ss:mmm(24小时制) ------------------------------------------------------------------------------------------------- - | 20 or 120 | yyyy-mm-dd hh:mi:ss(24小时制) ------------------------------------------------------------------------------------------------- - | 21 or 121 | yyyy-mm-dd hh:mi:ss:mmm(24小时制) 例如当前时间为：2005-9-12 13:20:00 我要取其中的：2005-9-12 select convert(char(10),'2005-9-12 13:20:00',120) CAST ( expression AS data_type ) 将某种数据类型的表达式显式转换为另一种数据类型 declare @a int cast(@a as varchar(10))--从而连接动态语句