MSSQL up to date in the law

 

Code

 1    DECLARE   @dt   datetime ;
 2    SET   @dt   =   GETDATE ();
 3    DECLARE   @table   table (caption  varchar ( 20 ),value  datetime );
 4 
 5    INSERT   INTO   @table   VALUES ( ' 0 ' , @dt );
 6    INSERT   INTO   @table   VALUES ( ' -1 ' , @dt - 1 );
 7    INSERT   INTO   @table   VALUES ( ' -0.1 ' , @dt - 0.1 );
 8    INSERT   INTO   @table   VALUES ( ' -0.01 ' , @dt - 0.01 );
 9    INSERT   INTO   @table   VALUES ( ' -0.001 ' , @dt - 0.001 );
10    INSERT   INTO   @table   VALUES ( ' -0.0001 ' , @dt - 0.0001 );
11    INSERT   INTO   @table   VALUES ( ' -0.00001 ' , @dt - 0.00001 );
12    INSERT   INTO   @table   VALUES ( ' -0.000001 ' , @dt - 0.000001 );
13    INSERT   INTO   @table   VALUES ( ' -0.0000001 ' , @dt - 0.0000001 );
14   
15    SELECT   *   FROM   @table
16 

 

 

show result:

 

caption　　　　　　　　   value
0　　　　　　　　 2010-05-05 18:50:03.547
-1　　　　　　　　2010-05-04 18:50:03.547
-0.1　　　　　　　2010-05-05 16:26:03.547
-0.01　　　　　　 2010-05-05 18:35:39.547
-0.001　　　　　  2010-05-05 18:48:37.147
-0.0001 　　　　  2010-05-05 18:49:54.907
-0.00001　　　　 2010-05-05 18:50:02.683
-0.000001　　　  2010-05-05 18:50:03.463
-0.0000001 　　  2010-05-05 18:50:03.540

 

So, in the end it is how he calculated. People immediately see a little focus, when -1, the date just minus one day so we can understand:

-1 = date minus one day.

Then the next, only you need to convert it to understand.

Date = today's date minus -0.1 0.1 Tian .

0.1 days, then 0.1 days is how much? Suddenly awakened, it turned out to be in accordance with the minutes of addition and subtraction.

1 day equals 60 minutes multiplied by 24 hours

Equal to 0.1 multiplied by 24 hours 60 minutes, and then multiplied by 0.1.

Such a right, this really is!

Reproduced in: https: //www.cnblogs.com/sofire/archive/2010/05/05/1728323.html