如何比较两个表并删除SQL中的重复行？

SELECT column1, column2, column3
FROM table1
UNION
SELECT column1, column2, column3
FROM table2;

SELECT column1, column2, column3
FROM table1
EXCEPT
SELECT column1, column2, column3
FROM table2;

SELECT column1, column2, column3
FROM table1
INTERSECT
SELECT column1, column2, column3
FROM table2;

SELECT DISTINCT column1, column2, column3
FROM table1;

SELECT column1, column2, column3
FROM table1
GROUP BY column1, column2, column3;

SELECT column1, column2, column3
FROM (
  SELECT column1, column2, column3, ROW_NUMBER() OVER (PARTITION BY column1, column2, column3 ORDER BY column1) AS row_num
  FROM table1
) AS subquery
WHERE subquery.row_num = 1;