CONVERT的使用方法:   
    
    ////////////////////////////////////////////////////////////////////////////////////////   
    
    格式:   
    CONVERT(data_type,expression[,style])   
    
    說明:   
    此樣式一般在時間類型(datetime,smalldatetime)與字符串類型(nchar,nvarchar,char,varchar)   
    相互轉(zhuǎn)換的時候才用到.   
    
    例子:   
    SELECT     CONVERT(varchar(30),getdate(),101)     now   
    結(jié)果為   
    now   
    ---------------------------------------   
    09/15/2001   
    
    /////////////////////////////////////////////////////////////////////////////////////   
    
    style數(shù)字在轉(zhuǎn)換時間時的含義如下   
    
    -------------------------------------------------------------------------------------------------   
    Style(2位表示年份)         |       Style(4位表示年份)           |         輸入輸出格式                                                                           
    -------------------------------------------------------------------------------------------------   
    -                                           |       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                             &n