SQL选择行，其中列值是唯一的（仅出现一次）

Question

Given the table

| id | Name |
| 01 | Bob  |
| 02 | Chad |
| 03 | Bob  |
| 04 | Tim  |
| 05 | Bob  |

I want to select the name and ID, from rows where the name is unique (only appears once)

This is essentially the same as How to select unique values of a column from table? , but notice that the author doesn't need the id, so that problem can be solved by a GROUP BY name HAVING COUNT(name) = 1

However, I need to extract the entire row (could be tens or hundreds of columns) including the id, where COUNT(name) = 1 , but I cannot GROUP BY id, name as every combination of those are unique.

EDIT:

Am using Google BigQuery.

Expected results:

| id | Name |
| 02 | Chad |
| 04 | Tim  |

Answer 1

Use correlated subquery

DEMO

select * from tablename a
where not exists (select 1 from tablename b where a.name=b.name having count(*)>1)

OUTPUT:

id  name
2   Chad
4   Tim

Answer 2

You can use NOT EXISTS :

SELECT t.*
FROM table t
WHERE NOT EXISTS (SELECT 1 FROM table t1 WHERE t1.name = t.Name AND t1.id <> t.id);

This would need index on table(id, name) to produce faster result set.

Answer 3

Simply do a GROUP BY . Use HAVING to make sure a name is only there once. Use MIN() to pick the only id for the name.

select min(id), name
from tablename
group by name
having count(*) = 1

Reading the table only once will increase performance! (And don't forget to create an index on (name, id).)

Answer 4

use exists and check uqique name

   select id,name 
    from table t1 
   where exists ( select 1 from table t2 where t1.name=t2.name

    having count(*)=1
)

Answer 5

Please try this.

SELECT 
   DISTINCT id,NAME
FROM
   tableName

Answer 6

You can use multiple subqueries to extract what you need.

SELECT * FROM tableName
WHERE name IN (SELECT name FROM (SELECT name, COUNT(name) FROM tableName
                                 GROUP BY name 
                                 HAVING COUNT(name) = 1) AS subQuery)

Answer 7

How about a simple aggregation?

select any_value(id), name
from t
group by name
having count(*) = 1;

BigQuery works quite well with aggregations so this might be quite efficient as well.

Answer 8

Below is for BigQuery Standard SQL and works for any number of columns w/o explicitly calling them out and does not require any join'ing or sub-selects

#standardSQL
SELECT t.*
FROM (
  SELECT ANY_VALUE(t) t
  FROM `project.dataset.table` t
  GROUP BY name
  HAVING COUNT(1) = 1
)