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mysql duplikatdata sletning

Du kan oprette en tabel med 1 post for hver af dubletterne:Slet derefter alle dup-posterne fra persontabellen, og indsæt derefter dup-posterne igen.

-- Setup for example create table people (fname varchar(10), lname varchar(10)); insert into people values ('Bob', 'Newhart'); insert into people values ('Bob', 'Newhart'); insert into people values ('Bill', 'Cosby'); insert into people values ('Jim', 'Gaffigan'); insert into people values ('Jim', 'Gaffigan'); insert into people values ('Adam', 'Sandler'); -- Show table with duplicates select * from people; -- Create table with one version of each duplicate record create table dups as select distinct fname, lname, count(*) from people group by fname, lname having count(*) > 1; -- Delete all matching duplicate records delete people from people inner join dups on people.fname = dups.fname AND people.lname = dups.lname; -- Insert single record of each dup back into table insert into people select fname, lname from dups; -- Show Fixed table select * from people;

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