hi,
TTITLE FORENAME SURNAME ADDRESS HOME_PHONE TOWN
mr Mohan Krishnan 42,MonksRD 1234567891 coventry,west midlands
null jason Rosss 13,CharterRD 1234567899 birmingham,west midlands
null Mohan Krishnan 42,MonksRD 1234567891 coventry,west midlands
mr Chris Hadland 30,watfordRD 5678912345 london,east midlands
mr Mohan Krishnan 42,MonksRD 4567891123 coventry,westmidlands
In this table the person Mohan is appeared three times and in the first row his title is mr and in the third row the title is null and in the 5 th row the title is mr and the home_phone is different from the other two rows, but all the three rows denote a same person. If this is the case then how will i find this duplicate record using a sql query..
my boss gave me 12 million records like this and he asked me to find all the duplicate records as i mentioned aboveand delete them.
please help me with this.
thanks in advance....
TTITLE FORENAME SURNAME ADDRESS HOME_PHONE TOWN
mr Mohan Krishnan 42,MonksRD 1234567891 coventry,west midlands
null jason Rosss 13,CharterRD 1234567899 birmingham,west midlands
null Mohan Krishnan 42,MonksRD 1234567891 coventry,west midlands
mr Chris Hadland 30,watfordRD 5678912345 london,east midlands
mr Mohan Krishnan 42,MonksRD 4567891123 coventry,westmidlands
In this table the person Mohan is appeared three times and in the first row his title is mr and in the third row the title is null and in the 5 th row the title is mr and the home_phone is different from the other two rows, but all the three rows denote a same person. If this is the case then how will i find this duplicate record using a sql query..
my boss gave me 12 million records like this and he asked me to find all the duplicate records as i mentioned aboveand delete them.
please help me with this.
thanks in advance....