SELECT
coll.title AS CollectionTitle,
cont.CollectionID,
cont.title AS ContainerTitle,
cont.ID as ContainerID,
cont.LevelContainerID,
cont.ContentID,
user.Title,
user.Value,
user.EADElementID
FROM tblCollections_Content cont
JOIN tblCollections_Collections coll
ON cont.collectionid = coll.id
JOIN tblCollections_UserFields user
ON cont.ContentId = user.ContentId
WHERE cont.title is NOT NULL
ORDER BY CollectionID, ContainerID
I have to assume you have a ContentID column in your tblCollections_Content to join to your tblCollections_UserFields and that the columns you specified are all in the tblCollections_UserFields table.
Depending on the referential integrity of these tables you might need to use outer joins to see all the rows.
solved Join 3rd Table in MYSQL [closed]