如何在使用内部联接合并两个表时将列设置为PRIMARY KEY（两个联接表中没有主键）

Question

How to set a column to PRIMARY KEY while merging two tables using inner join ?( there is no primary key in the two joining tables ) please help.

create table merge_aws AS
select aws.id,aws.date,aws.time,aws.pmer,aws.dd,aws.ff,aws.t,masterfile.station,masterfile.latitude,masterfile.longitude
from aws
inner join masterfile
on aws.id=masterfile.call_sign;

Answer 1

Use alter table after creation like this sample:

CREATE TABLE merge_aws AS select 
    aws.id,
    aws.date,
    aws.time,
    aws.pmer,
    aws.dd,
    aws.ff,
    aws.t,
    masterfile.station,
    masterfile.latitude,
    masterfile.longitude
from
    aws
        inner join
    masterfile ON aws.id = masterfile.call_sign;

ALTER TABLE merge_aws ADD COLUMN prim INT NOT NULL AUTO_INCREMENT , ADD PRIMARY KEY (prim) ;

Thanks