How can I compare two tables with same structure and find unmatched records with mySQL?

问题

I have two tables with same structure.

TABLE-1
--------
ID  NAME
1   AAAA
2   BBBB
3   CCCC
4   DDDD

TABLE-2
--------
ID  NAME
1   AAAA
2   BBBB
3   CCCC
4   DDDD
5   eeee
6   ffff
7   gggg
8   hhhh
9   iiii

How I can compare this tables with MySQL and adding unmatched rows from TABLE-2 in TABLE-1?

回答1:

Insert into table-1 (select id,name from table-2 where id not in (select id from table-1));

回答2:

If any of the ID, NAME is defined as unique key or combined unique (e.g primary key (ID, NAME)) Then its possible to utilize INSERT IGONRE .. SELECT

INSERT IGNORE INTO TABLE1 SELECT * FROM TABLE2

If they are key, duplicate columns will be ignored while inserting as we are using INSERT IGNORE

回答3:

I find the answer. This code working correctly and returnig unmatched rows.

SELECT * FROM TABLE-1
WHERE TABLE-1.ID
NOT IN (
SELECT TABLE-2.ID
FROM TABLE-2
WHERE TABLE-2.ID=TABLE-1.ID
)

来源：https://stackoverflow.com/questions/9584885/how-can-i-compare-two-tables-with-same-structure-and-find-unmatched-records-with