Using the distinct function in SQL

Question

I have a SQL query I am running. What I was wanting to know is that is there a way of selecting the rows in a table where the value in on one of those columns is distinct? When

Answer 1

As soulmerge and Shiraz have mentioned you'll need to use a GROUP BY and subselect. This worked for me.

DECLARE @table TABLE (
    [Teacher] [NVarchar](256) NOT NULL ,
    [Student] [NVarchar](256) NOT NULL 
)

INSERT INTO @table VALUES ('Teacher 1', 'Student 1')
INSERT INTO @table VALUES ('Teacher 1', 'Student 2')
INSERT INTO @table VALUES ('Teacher 2', 'Student 3')
INSERT INTO @table VALUES ('Teacher 2', 'Student 4')

SELECT 
    T.[Teacher],  
    (
        SELECT TOP 1 T2.[Student]
        FROM @table AS T2 
        WHERE T2.[Teacher] = T.[Teacher]
    ) AS [Student]
FROM @table AS T
GROUP BY T.[Teacher]

Results

Teacher 1, Student 1
Teacher 2, Student 3