The INSERT statement conflicted with the constraint

Question

I want to make a date constraint in my table (I use sql server). I want to make sure that the date in one of my columns is later than the current date and time (I know it sounds weird, but it's an assignment so I have no choice). I tried to do it this way:

ALTER TABLE sales ADD CONSTRAINT d CHECK (Date >  CURRENT_TIMESTAMP);

but later when inserting DEFAULT into date column I get the following error:

The INSERT statement conflicted with the CHECK constraint "d". 
The conflict occurred in database "Newsagents", table "dbo.Sales", column 'Date'.

This is the said table:

CREATE TABLE Sales (
ID INT IDENTITY(1,1) NOT NULL  ,
ClientID INT REFERENCES Client(ClientID),
ProductNumber CHAR(10)  REFERENCES Product(ProductNumber),
Quantity INT NOT NULL,
Price FLOAT NOT NULL ,
Date TIMESTAMP  NOT NULL,
PRIMARY KEY ( ID ) 

and this how I insert my data into Sales column and get the constraint conflict:

DECLARE @counter INT
DECLARE @quantity int
DECLARE @prodNum varchar(20)
SET @counter = 0 
WHILE @counter < 10  
BEGIN
SET @quantity = (select FLOOR(RAND()*100))
SET @prodNum = (select TOP 1 ProductNumber from Product Order by NEWID())

 insert into Sales (ClientID, ProductNumber, Quantity, Price, Date )
 values(
 (select TOP 1 ClientID from Client Order by NEWID()),
 (select @prodNum),
 (select @quantity),
 ((select @quantity)*(select TOP 1 Price from Product where ProductNumber = @prodNum)),
 DEFAULT
 )
 SET @counter = @counter + 1 
 END 

Is there a different way to do this? Or am I doing something wrong?

Answer 1

ALTER TABLE sales ADD CONSTRAINT d CHECK (Date >  GETDATE());

change the Date column to datetime