MySQL GROUP BY를 사용하여 특정 회사의 직원 이름을 얻으시겠습니까?

먼저 테이블을 생성하겠습니다 -

mysql> create table DemoTable642(
   EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,EmployeeName archar(100), EmployeeCompanyNamevarchar(100)
);
Query OK, 0 rows affected (0.81 sec)

삽입 명령을 사용하여 테이블에 일부 레코드 삽입 -

mysql> insert into DemoTable642(EmployeeName,EmployeeCompanyName) values('John','Google');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable642(EmployeeName,EmployeeCompanyName) values('Carol','Microsoft');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable642(EmployeeName,EmployeeCompanyName) values('John','Amazon');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable642(EmployeeName,EmployeeCompanyName) values('Carol','Google');
Query OK, 1 row affected (0.37 sec)
mysql> insert into DemoTable642(EmployeeName,EmployeeCompanyName) values('John','Flipkart');
Query OK, 1 row affected (0.14 sec)

select 문을 사용하여 테이블의 모든 레코드 표시 -

mysql> select *from DemoTable642;

이것은 다음과 같은 출력을 생성합니다 -

+------------+--------------+---------------------+
| EmployeeId | EmployeeName | EmployeeCompanyName |
+------------+--------------+---------------------+
| 1          | John         | Google              |
| 2          | Carol        | Microsoft           |
| 3          | John         | Amazon              |
| 4          | Carol        | Google              |
| 5          | John         | Flipkart            |
+------------+--------------+---------------------+
5 rows in set (0.00 sec)

다음은 특정 회사에서 직원 이름을 가져오는 쿼리입니다 -

mysql> select EmployeeName from DemoTable642
   where EmployeeCompanyName="Google"
   group by EmployeeName;

이것은 다음과 같은 출력을 생성합니다 -

+--------------+
| EmployeeName |
+--------------+
| John         |
| Carol        |
+--------------+
2 rows in set (0.00 sec)