Question

I have a table Messages in SQL Server 2012.
There are three columns in table

ID which is an identity column, 
MessageID (int) which is a foreign key to other table and 
IsRead field which is a bit not null column.

At a given point of time table can contain huge number of records with IsRead column value either 1 or 0.
I want to write a single query in which I find count of read and unread messages in two separate columns.
I am trying to use new windows function introduced in SQL Server 2012 for efficiency.
How can I do it ?

Answer 1

Please check whether this helps.

SELECT 
    IsRead, 
    COUNT(*) ReadCount 
FROM 
    YourTable 
GROUP BY IsRead

Or you can select in two columns like:

SELECT  SUM(IsRead - 0) AS ReadCount,
        SUM(1 - IsRead) AS UnreadCount
FROM    YourTable