Question

I want to select all records, but have the query only return a single record per Product Name. My table looks similar to:

SellId   ProductName Comment
1          Cake        dasd 
2          Cake        dasdasd
3          Bread       dasdasdd  

where the Product Name is not unique. I want the query to return a single record per ProductName with results like:

SellId   ProductName Comment
1          Cake        dasd 
3          Bread       dasdasdd 

I have tried this query,

Select distict ProductName,Comment ,SellId from TBL#Sells

but it is returning multiple records with the same ProductName. My table is not realy as simple as this, this is just a sample. What is the solution? Is it clear?

Answer 1

Select  ProductName, 
min(Comment) , min(SellId) from TBL#Sells
group by ProductName

If y ou only want one record per productname, you ofcourse have to choose what value you want for the other fields.

If you aggregate (using group by) you can choose an aggregate function,
htat’s a function that takes a list of values and return only one : here I have chosen MIN : that is the smallest walue for each field.

NOTE : comment and sellid can come from different records, since MIN is taken…

Othter aggregates you might find useful :

FIRST : first record encountered
LAST : last record encoutered
AVG : average 
COUNT : number of records

first/last have the advantage that all fields are from the same record.