C＃仅显示sql表中具有空值的值

I am connecting to an SQL server. I have a column which has date and time and another which has the user name. Once i connect to the database it shows everything except the null values in the column of date and time. I need to show only the column of data and time which holds null values and the user with the null value. How do i Display the null values but only the null values?I am connecting to an SQL server. I have a colu