Oracle PL/SQL/View/Inline View

inline view

 
SQL>
SQL>
SQL> CREATE TABLE departments
  2  (department_id           number(10)            not null,
  3   department_name      varchar2(50)      not null,
  4   CONSTRAINT departments_pk PRIMARY KEY (department_id)
  5  );
Table created.
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SQL>
SQL>
SQL> insert into departments ( department_id, department_name )
  2                    values( 1,             "Data Group" );
1 row created.
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SQL> insert into departments ( department_id, department_name )
  2                    values( 2,             "Purchasing" );
1 row created.
SQL>
SQL> insert into departments ( department_id, department_name )
  2                    values( 3,             "Call Center" );
1 row created.
SQL>
SQL> insert into departments ( department_id, department_name )
  2                    values( 4,             "Communication" );
1 row created.
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SQL>
SQL>
SQL> CREATE TABLE employees
  2  ( employee_id          number(10)      not null,
  3    last_name            varchar2(50)      not null,
  4    email                varchar2(30),
  5    hire_date            date,
  6    job_id               varchar2(30),
  7    department_id        number(10),
  8    salary               number(6),
  9    manager_id           number(6),
 10    CONSTRAINT           employees_pk PRIMARY KEY (employee_id),
 11    CONSTRAINT           fk_departments FOREIGN KEY (department_id) REFERENCES departments(department_id)
 12  );
Table created.
SQL>
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary,department_id ,manager_id)
  2                values ( 1001, "Lawson", "lawson@g.ru", "01-JAN-2002","MGR", 30000,1 ,1004);
1 row created.
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
  2                values ( 1002, "Wells", "wells@g.ru", "01-JAN-2002", "DBA", 20000,2, 1005 );
1 row created.
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SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
  2                 values( 1003, "Bliss", "bliss@g.ru", "01-JAN-2002", "PROG", 24000,3 ,1004);
1 row created.
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
  2                 values( 1004,  "Kyte", "tkyte@a.ru", SYSDATE-3650, "MGR",25000 ,4, 1005);
1 row created.
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
  2                 values( 1005, "Viper", "sdillon@a .ru", SYSDATE, "PROG", 20000, 1, 1006);
1 row created.
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id,manager_id)
  2                 values( 1006, "Beck", "clbeck@g.ru", SYSDATE, "PROG", 20000, 2, null);
1 row created.
SQL>
SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
  2                 values( 1007, "Java", "java01@g.ru", SYSDATE, "PROG", 20000, 3, 1006);
1 row created.
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SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
  2                 values( 1008, "Oracle", "wvelasq@g.ru", SYSDATE, "DBA", 20000, 4, 1006);
1 row created.
SQL>
SQL>  select department_name, count(*),
  2           to_char( (count(*)/total_emp.cnt)*100, "90.99" ) || "%" pct
  3      from departments,
  4           employees, ( select count(*) cnt from employees ) total_emp
  5     where departments.department_id = employees.department_id
  6     group by department_name, total_emp.cnt
  7     /
DEPARTMENT_NAME                                      COUNT(*) PCT
-------------------------------------------------- ---------- -------
Communication                                               2  25.00%
Data Group                                                  2  25.00%
Purchasing                                                  2  25.00%
Call Center                                                 2  25.00%
SQL>
SQL> drop table employees cascade constraints;
Table dropped.
SQL> drop table departments cascade constraints;
Table dropped.
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