mysql select from where a condition is met

Question

My table structure is as follows

ProductID |  Image  | Default
1            1.jpg     N
1            2.jpg     Y
1            3.jpg     N
2            4.jpg     N
2            5.jpg     N
3            6.jpg     Y
3            7.jpg     N

I'm Trying to get a return of all producID where there is no default image 'N' , eg the above should return productID 2. Sorry no code attempt , as i'm not sure what to do at all.

Answer 1

Group by the product and select only those having none default=Y

select productID
from your_table
group by productID
having sum(`default` = 'Y') = 0

Answer 2

Try this:

SELECT t1.productID
FROM yourtable t1
WHERE NOT EXISTS(
    SELECT 'DEFAULT'
    FROM yourtable t2
    WHERE T2.productid = t1.productid
    AND T2.`default` = 'Y'
)

Answer 3

This SQL code does what you want:

SELECT productID FROM  
    (SELECT productID, SUM(table.default = 'Y') AS Y_count 
    FROM table
    GROUP BY productID) AS tbl
WHERE Y_count = 0

Answer 4

如果default是数据库中的一列，则可以使用：

Select * from mytabale where 'Default'='Y'