SQL query to break at first match of the condition

Question

Need help to achieve the following result.

I have the following table entries ordered by name

Name  Rank
----------
A      1
B      1
C      2
D      1
E      2

I am in an attempt to write an sql query to get the following results

Name  Rank
---------
A      1
B      1

The condition is like as soon as we find rank > 1 stop further traversal and return all items prior to the 1st matched row in this example all rows prior to Name 'C'

Answer 1

SELECT
  *
FROM
(
  SELECT
    ROW_NUMBER() OVER (                  ORDER BY name)  AS name_row_number,
    ROW_NUMBER() OVER (PARTITION BY rank ORDER BY name)  AS rank_row_number,
    yourTable.*
  FROM
    yourTable
)
  ordered
WHERE
  name_row_number = rank_row_number

The example below shows that only for the first two rows do these ROW_NUMBER() values match.

Name  Rank  name_row_number  rank_row_number
---------------------------------------------
A      1     1                1
B      1     2                2
C      2     3                  1
D      1     4                3
E      2     5                  2

I can't imagine that it's very efficient on large data sets though.

Answer 2

SELECT * FROM
(
  SELECT name,rank FROM test
  ORDER BY name,rank
)
WHERE RowNum < (
                 select min(rnk)
                 from (
                       SELECT 
                       case rank when 2 then 'x' else 'y' end as tag,
                       row_number() over(order by name,rank) as rnk
                       from test
                 )Z 
                 where tag='x'
                )

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