How to insert Distinct Records from Table A to Table B (both tables have same structure)

问题

I want to insert only Distinct Records from Table "A" to Table "B". Assume both the tables has same structure.

回答1:

If by DISTINCT you mean unique records that are on TableB that aren't already in TableA, then do the following:

INSERT INTO TableB(Col1, Col2, Col3, ... , Coln)
SELECT DISTINCT A.Col1, A.Col2, A.Col3, ... , A.Coln
FROM TableA A
LEFT JOIN TableB B
ON A.KeyOfTableA = B.KeyOfTableB
WHERE B.KeyOfTableB IS NULL

回答2:

INSERT INTO B SELECT DISTINCT * FROM A

You might not want the id column of the table to be part of the distinct check, so use this solution if that's the case: https://stackoverflow.com/a/5171345/453673

回答3:

INSERT INTO TableB
    (Col1, Col2, ...)
    SELECT DISTINCT Col1, Col2, ...
        FROM TableA

回答4:

    INSERT INTO TableB
            SELECT *
            FROM TableA AS A
            WHERE NOT EXISTS(SELECT * FROM TableB AS B WHERE B.Field1 = A.Field1) 
-- If need: B.Field2 = A.Field2 and B.Field3 = A.Field3

来源：https://stackoverflow.com/questions/5171328/how-to-insert-distinct-records-from-table-a-to-table-b-both-tables-have-same-st