编辑代码

CREATE TABLE A
                 (
                     id         int,
                     val        text
                 );
CREATE TABLE B
                 (
                     id         int,
                     val        text
                 );
 CREATE TABLE AB
                 (
                     id         int,
                     val        text
                 );
INSERT INTO A VALUES(1,"AB");
INSERT INTO B VALUES(1,"AB");
INSERT INTO A VALUES(2,"A");
INSERT INTO A VALUES(3,"B");

INSERT INTO AB
SELECT DISTINCT * FROM A
UNION
SELECT DISTINCT * FROM B
ORDER BY id;

SELECT * FROM AB;