mysql - How do I Compare columns of records from the same table? -

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here testing table data:

testing

id      name            payment_date   fee                amt 1       banka           2016-04-01     100                20000 2       bankb           2016-04-02     200                10000 3       banka           2016-04-03     100                20000 4       bankb           2016-04-04     300                20000

i trying compare fields name, fee , amt of each data records see whether there same values or not. if got same value, i'd mark 'y' record. here expected result

id      name            payment_date   fee                amt      samedataexistyn 1       banka           2016-04-01     100                20000    y 2       bankb           2016-04-02     200                10000    n 3       banka           2016-04-03     100                20000    y 4       bankb           2016-04-04     300                20000    n

i have tried these 2 methods below. looking other solutions can pick out best 1 work.

method 1.

select t.*, iif((select count(*) testing name=t.name , fee=t.fee , amt=t.amt)=1,'n','y') samedataexistyn testing t

method 2.

select t.*, case when ((b.name = t.name)                         , (b.fee = t.fee) , (b.amt = t.amt)) 'y' else 'n' end samedataexistyn testing t left join ( select name,  fee, amt             testing             group name,  fee, amt             having count(*)>1  ) b on b.name = t.name                                       , b.fee = t.fee                                       , b.amt = t.amt

here method, think have run tests on data find out best:

select   t.*,   case when exists(     select * testing id <> t.id , name = t.name , fee = t.fee , amt = t.amt   ) 'y' else 'n' end samedataexistyn   testing t  ;

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