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select sum(Post.rating) from Post
        left join assetData on 
                Post.assetId=assetData.assetId
        left join asset on 
                asset.assetId=assetData.assetId
                and assetData.revisionDate=(SELECT max(revisionDate) from assetData where assetData.assetId=asset.assetId)
        where 
                Post.threadId=?
                and asset.assetId!=?