在表中查找重复行

Posted 2021-02-25

Field1 + Field2 + Field3 should create 1 entry for each unique row in the DB. In an employee table, this would be FirstName + LastName + EmployeeNumber

SELECT * FROM TABLE WHERE field1 + field2 + field3 IN 
(
	SELECT field1 + field2 + field3 FROM TABLE GROUP BY field1 + field2 + field3 HAVING COUNT(*) > 1
) 
AND uniqueID NOT IN 
(
	SELECT MAX(uniqueID) FROM xer_regis_new GROUP BY field1 + field2 + field3 HAVING COUNT(*) > 1
)