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Delete rows with duplicate and similar content & get row with maximum number with MySQL select statement?
Let us first create a table −
mysql> create table DemoTable1468 -> ( -> Id int, -> Name varchar(20), -> Age int -> ); Query OK, 0 rows affected (1.21 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1468 values(100,'Chris',23); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1468 values(101,'Bob',25); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1468 values(102,'David',30); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1468 values(100,'Chris',23); Query OK, 1 row affected (0.35 sec) mysql> insert into DemoTable1468 values(100,'Chris',38); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1468 values(101,'Bob',23); Query OK, 1 row affected (0.13 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1468;
This will produce the following output −
+------+-------+------+ | Id | Name | Age | +------+-------+------+ | 100 | Chris | 23 | | 101 | Bob | 25 | | 102 | David | 30 | | 100 | Chris | 23 | | 100 | Chris | 38 | | 101 | Bob | 23 | +------+-------+------+ 6 rows in set (0.00 sec)
Here is the query to delete rows with duplicate and similar content and get row with max number with select statement −
mysql> select Id,Name,Age from DemoTable1468 -> group by Name,Id -> having max(Age);
This will produce the following output −
+------+-------+------+ | Id | Name | Age | +------+-------+------+ | 100 | Chris | 23 | | 101 | Bob | 25 | | 102 | David | 30 | +------+-------+------+ 3 rows in set (0.00 sec)
Updated on: 10-Dec-2019
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