sql - Delete duplicate entries keeping one entry of each if id column not available -


i have tried,

delete student firstname in (     select firstname      (      select firstname,      row_number() over(partition firstname order firstname) rn      student     ) student     rn > 1 );

but deleting both duplicate records. please correct query. in advance.

you can use cte

    mycte          (        select [firstname], row_number() over(partition firstname order firstname) rn        student     )     delete mycte rn > 1;     select * students;

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