Equivalent of Oracle’s RowID in MySQL -

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is there equivalent of oracle's rowid in mysql?

delete my_table rowid not in (select max(rowid) my_table group field1,field2)

i want make mysql equivalent of query!!!

what i'm trying is, : my_table has no primary key.. i'm trying delete duplicate values , impose primary key (composite of field1, field2)..!!

in mysql use session variables achive functionality:

select @rowid:=@rowid+1 rowid table1, (select @rowid:=0) init order sorter_field

but can not make sorts on table trying delete in subqueries.

upd: need create temp table, insert ranging subquery temp table , delete original table joining temporary table (you need unique row identifier):

create temporary table duplicates ...  insert duplicates (rowid, field1, field2, some_row_uid) select   @rowid:=if(@f1=field1 , @f2=field2, @rowid+1, 0) rowid,   @f1:=field1 field1,   @f2:=field2 field2,   some_row_uid testruns t, (select @rowid:=null, @f1:=null, @f2:=null) init order field1, field2 desc;  delete my_table using my_table join duplicates   on my_table.some_row_uid = duplicates.some_row_uid , duplicates.rowid > 0

since 1 time operation, should not bring overhead.


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