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) ------------------------------------------------------------------------------------------------------------
例：得到前个月倒数第三天日期: select dateadd(Day ,-3,convert(varchar(8),getdate(),120)+'01')