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sqlrow-numbersequential

Sequentially number rows by keyed group in SQL?

Is there a way in SQL to sequentially add a row number by key group?

Assume a table with arbitrary (CODE,NAME) tuples. Example table:

CODE NAME    
---- ----
A    Apple
A    Angel
A    Arizona
B    Bravo
C    Charlie
C    Cat
D    Dog
D    Doppler
D    Data
D    Down

Desired projection using CODE as the grouping attribute:

CODE C_NO NAME    
---- ---- ----
A    0    Apple
A    1    Angel
A    2    Arizona
B    0    Bravo
C    1    Charlie
C    0    Cat
D    0    Dog
D    1    Data
D    2    Down
D    3    Doppler

Thanks,

Solution

  • This covers most bases.

    SELECT
    CODE,
    ROW_NUMBER() OVER (PARTITION BY CODE ORDER BY NAME) - 1 As C_NO,
    NAME
FROM
    MyTable