Select individual records only

问题

I have a table as such

custno, type, color
A1234, B, Red
A1234, C, Blue
A1277, B, Red
A1288, A, Black
A1288, B, Red
A1289, A, Black

I need to retrieve only the unique records A1277 and A1289 that are only found once.

回答1:

This will display the custNO on the result list,

SELECT  custNo
FROM    tableName
GROUP   BY custNO
HAVING  COUNT(*) = 1

but if you want to get the whole row,

SELECT  a.*
FROM    tableName a
        INNER JOIN
        (
            SELECT  custNo
            FROM    tableName
            GROUP   BY custNO
            HAVING  COUNT(*) = 1
        ) b ON a.custNo = b.custNo

• SQLFiddle Demo (both queries)

回答2:

SELECT custno
FROM yourTable
GROUP BY custno
HAVING COUNT(*) = 1

Example Fiddle

回答3:

Try this as this will prevent costly join operation--

SELECT custno,type,color FROM ( SELECT custno, type, color, COUNT(custno) OVER(PARTITION BY custno) CNT FROM tableName )TMP WHERE CNT=1

来源：https://stackoverflow.com/questions/15364846/select-individual-records-only