To find duplicate rows, use GROUP BY and HAVING in MySQL. Let us first create a table −
mysql> create table DemoTable1494 -> ( -> ShippingDate datetime, -> CustomerCountryName varchar(20) -> ); Query OK, 0 rows affected (0.63 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1494 values('2018-09-10 12:34:50','US');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable1494 values('2019-09-10 12:34:50','AUS');
Query OK, 1 row affected (0.65 sec)
mysql> insert into DemoTable1494 values('2018-09-10 11:00:00','US');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable1494 values('2017-12-31 01:10:40','UK');
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable1494 values('2019-09-10 05:00:50','AUS');
Query OK, 1 row affected (0.49 sec)Display all records from the table using select statement −
mysql> select * from DemoTable1494;
This will produce the following output −
+---------------------+---------------------+ | ShippingDate | CustomerCountryName | +---------------------+---------------------+ | 2018-09-10 12:34:50 | US | | 2019-09-10 12:34:50 | AUS | | 2018-09-10 11:00:00 | US | | 2017-12-31 01:10:40 | UK | | 2019-09-10 05:00:50 | AUS | +---------------------+---------------------+ 5 rows in set (0.00 sec)
Following is the query to find duplicate rows in MySQL −
mysql> select ShippingDate,CustomerCountryName,count(*) as c -> from DemoTable1494 -> group by date(ShippingDate),CustomerCountryName -> having c >=2 -> order by c;
This will produce the following output −
+---------------------+---------------------+---+ | ShippingDate | CustomerCountryName | c | +---------------------+---------------------+---+ | 2018-09-10 12:34:50 | US | 2 | | 2019-09-10 12:34:50 | AUS | 2 | +---------------------+---------------------+---+ 2 rows in set (0.00 sec)