当其中两行需要唯一时,选择三行(SQL)

如果域名称、索引路径的某些组合有多行,那么您希望从这些行中看到集合名称的哪个值?如果你不介意哪种价值,那就做:

SELECT domain_name, index_path, MIN(collection_name) collection_name
FROM TABLENAMEHERE
GROUP BY domain_name, index_path;

select domain_name, index_path, collection_name
  from my_table outr
       inner join 
         (select domain_name, index_path, collection_name, 
                 max(gen_timestamp) 
                    over (partition by domain_name, index_path) gen_timestamp
            from my_table) innr
 where outr.domain_name = innr.domain_name
   and outr.index_path  = innr.index_path
   and outr.collection_name = innr.collection_name
   and outr.gen_timestamp   = innr.gen_timestamp

只是替换 unique 具有 distinct 在你的询问中。

哦。。。

那么应该是这样的:

select [domain_name], [index_path], min([collection_name]) 
from TABLENAMEHERE
group by [domain_name], [index_path]

您可以按域名和索引路径分组,每个组包含一个(最小或最大)集合名称值。