Database: MS SQL 2008
SELECT Listing.Title, Listing.MLS, Pictures.PictureTH, Pictures.Picture, Listing.ID
FROM Listing INNER JOIN Pictures ON Listing.ID = Pictures.ListingID
WHERE (Pictures.ID = (SELECT MIN(ID) FROM Pictures WHERE (ListingID = Listing.ID)))
The issue is, I have several "Listings" without a Picture, and because of this SQL script they don't show up. How can I get them to show up?
Maybe give the Pictures.Picture Column a value开发者_StackOverflow of "default.jpg" if the value is null? I'm pretty lost on this, so if someone could help, that'd be amazing. Sorry if I'm asking the question poorly as well, I dont understand how to ask really what I need it to do. But ask for more details and I'll post them.
Each Listing can have as many pictures as the user wants, I need this script to display a Listing even if it doesn't have a picture.
PHASE 2
Thank you all. So far I'm learning some new commands I never even knew existed. The issue now is its returning a row for each picture a listing has. But the default image is working great.
SELECT Listing.Title, Listing.MLS, coalesce(Pictures.PictureTH, '../default_th.jpg') as PictureTH, coalesce(Pictures.Picture, '../default.jpg') as Picture, Listing.ID FROM Listing LEFT
OUTER JOIN Pictures ON Listing.ID = Pictures.ListingID
How can I get it so it only returns 1 row per ListingID ?
Two things:
- Use
left outer join
instead ofinner join
to get all the listings, even with missing pictures. Use
coalesce
to apply the defaultSELECT Listing.Title , Listing.MLS , Pictures.PictureTH , coalesce(Pictures.Picture, 'default.jpg') as Picture , Listing.ID FROM Listing LEFT OUTER JOIN Pictures ON Listing.ID = Pictures.ListingID
EDIT To limit to one row:
SELECT Listing.Title
, Listing.MLS
, Pictures.PictureTH
, coalesce(Pictures.Picture, 'default.jpg') as Picture
, Listing.ID
FROM Listing
LEFT OUTER JOIN Pictures
ON Listing.ID = Pictures.ListingID
WHERE Pictures.ID is null
OR Pictures.ID = (SELECT MIN(ID)
FROM Pictures
WHERE (ListingID = Listing.ID)))
if you want to set the default value if the Pic is null you can do this via COALESCE key word:
SELECT Listing.Title, Listing.MLS, Pictures.PictureTH,
COALESCE (Pictures.Picture, 'default.jpg') AS Pictures, Listing.ID
FROM Listing LEFT JOIN Pictures
ON Listing.ID = Pictures.ListingID
WHERE (Pictures.ID = (SELECT MIN(ID)
FROM Pictures WHERE (ListingID = Listing.ID)))
You can also achieve this via IsNull like below:
SELECT Listing.Title, Listing.MLS, Pictures.PictureTH,
ISNULL(Pictures.Picture, 'default.jpg') AS Pictures, Listing.ID
FROM Listing LEFT JOIN Pictures
ON Listing.ID = Pictures.ListingID
WHERE (Pictures.ID = (SELECT MIN(ID)
FROM Pictures WHERE (ListingID = Listing.ID)))
you can read here about IsNull and Coalesce
Use left outer join
instead of inner join
Inner join
will return results if and only if there is a result that satisfies the join.
Left outer join
will return results from the left side table, and if the join is satisfied also add results from the right side table..
If you need to convert the null values returned from the non-satisfying joins, then use coalesce
function like coalesce(Pictures.Picture, 'default.jpg')
Need to do a LEFT join
SELECT Listing.Title, Listing.MLS, Pictures.PictureTH, Pictures.Picture, Listing.ID
FROM Listing LEFT JOIN Pictures ON Listing.ID = Pictures.ListingID
Landmine, what database are you using?
If it's sql server 2005 or above or oracle, you can use the pivot command to achieve this.
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