MySQL old table deduplication data import new table and give primary key ID new value

Business Requirements:
A table has the Id,n1,n2,n3 field, which is a new empty table,

Table B has id,n1,n2,n3,n4,n5 fields, such as old tables containing data,

Now the record of the N1,N2,N3 combination in B table is re-imported into a table, and a table primary key is also entered value

Scenario: The records of B table after the query to go to the weight, while the results of the records are numbered, the sequence number as a table to insert the ID value, SQL statement as follows:

INSERT INTO A表(id,n1,n2,n3) select @row :[email protected]row+1 AS id,t1.* from (SELECT DISTINCT n1,n2,n3 FROM B表) t1,(select @row :=0) as t2

MySQL old table deduplication data import new table and give primary key ID new value