MySQL SELECT DISTINCT and count?

MySQLMySQLi Database

You need to use GROUP BY command with aggregate function count(*) from MySQL to achieve this. The syntax is as follows:

SELECT yourColumnName,COUNT(*) AS anyVariableNameFROM yourTableName GROUP BY yourColumnName;

To understand the above syntax, let us create a table. The query to create a table is as follows:

mysql> create table selectDistinct_CountDemo
   -> (
   -> Id int NOT NULL AUTO_INCREMENT,
   -> Name varchar(10),
   -> AppearanceId int,
   -> PRIMARY KEY(Id)
   -> );
Query OK, 0 rows affected (0.63 sec)

Insert some records in the table using insert command. The query is as follows:

mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('Larry',1);
Query OK, 1 row affected (0.18 sec)
mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('John',2);
Query OK, 1 row affected (0.24 sec)
mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('Larry',3);
Query OK, 1 row affected (0.12 sec)
mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('Larry',10);
Query OK, 1 row affected (0.18 sec)
mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('Carol',11);
Query OK, 1 row affected (0.18 sec)
mysql> insert into selectDistinct_CountDemo(Name,AppearanceId) values('Larry',15);
Query OK, 1 row affected (0.18 sec)

Display all records from the table using select statement. The query is as follows:

mysql> select *from selectDistinct_CountDemo;

The following is the output:

+----+-------+--------------+
| Id | Name  | AppearanceId |
+----+-------+--------------+
|  1 | Larry |            1 |
|  2 | John  |            2 |
|  3 | Larry |            3 |
|  4 | Larry |           10 |
|  5 | Carol |           11 |
|  6 | Larry |           15 |
+----+-------+--------------+
6 rows in set (0.00 sec)

Here is the query to select distinct and count:

mysql> select Name,count(*) as TotalAppearance from selectDistinct_CountDemo
   -> group by Name;

The following is the output:

+-------+-----------------+
| Name  | TotalAppearance |
+-------+-----------------+
| Larry |               4 |
| John  |               1 |
| Carol |               1 |
+-------+-----------------+
3 rows in set (0.00 sec)
raja
Published on 25-Feb-2019 10:09:04
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