MySQL query to select the values having multiple occurrence and display their count
For this, use GROUP BY HAVING clause. Let us first create a table −
mysql> create table DemoTable673(
Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
Value int
);
Query OK, 0 rows affected (0.59 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable673(Value) values(10);
Query OK, 1 row affected (0.21 sec)
mysql> insert into DemoTable673(Value) values(20);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable673(Value) values(10);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable673(Value) values(30);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable673(Value) values(20);
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable673(Value) values(10);
Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable673(Value) values(10);
Query OK, 1 row affected (0.28 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable673;
This will produce the following output −
+----+-------+
| Id | Value |
+----+-------+
| 1 | 10 |
| 2 | 20 |
| 3 | 10 |
| 4 | 30 |
| 5 | 20 |
| 6 | 10 |
| 7 | 10 |
+----+-------+
7 rows in set (0.00 sec)
Following is the query to display only the values having multiple occurrences −
mysql> select Id,count(*) as myValue from DemoTable673 group by Value having count(*) > 1;
This will produce the following output −
+----+---------+
| Id | myValue |
+----+---------+
| 1 | 4 |
| 2 | 2 |
+----+---------+
2 rows in set (0.00 sec)
Published on 26-Aug-2019 10:07:17
