kurs:joins
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kurs:joins [2008/10/23 12:25] 127.0.0.1 external edit |
kurs:joins [2020/05/12 10:09] admin |
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| on employees.department_id = departments.department_id | on employees.department_id = departments.department_id | ||
| order by department_name desc, last_name, first_name; | order by department_name desc, last_name, first_name; | ||
| + | |||
| + | SELECT EMPLOYEES.FIRST_NAME, | ||
| + | EMPLOYEES.LAST_NAME, | ||
| + | DEPARTMENTS.DEPARTMENT_NAME, | ||
| + | LOCATIONS.CITY | ||
| + | FROM HR.EMPLOYEES left outer join HR.DEPARTMENTS on | ||
| + | DEPARTMENTS.DEPARTMENT_ID = EMPLOYEES.DEPARTMENT_ID | ||
| + | left outer join HR.LOCATIONS on | ||
| + | LOCATIONS.LOCATION_ID = DEPARTMENTS.LOCATION_ID | ||
| + | order by department_name desc | ||
| SELF JOIN | SELF JOIN | ||
| Line 32: | Line 42: | ||
| order by m.employee_id | order by m.employee_id | ||
| + | SELECT EMPLOYEES.FIRST_NAME, | ||
| + | EMPLOYEES.LAST_NAME, | ||
| + | MANAGER.FIRST_NAME "MANAGER FIRST_NAME", | ||
| + | MANAGER.LAST_NAME "MANAGER LAST_NAME" | ||
| + | FROM HR.EMPLOYEES right join EMPLOYEES MANAGER | ||
| + | on ( (EMPLOYEES.MANAGER_ID = MANAGER.EMPLOYEE_ID) ) | ||
| + | where employees.employee_id is null | ||
| + | (89 rows) | ||
| + | |||
| + | |||
| + | </code> | ||
| + | |||
| + | Join über mehrere Tabellen hinweg | ||
| + | <code> | ||
| + | SELECT | ||
| + | first_name, | ||
| + | last_name, | ||
| + | coalesce(department_name, '[kein department]'), | ||
| + | city, | ||
| + | country_name, | ||
| + | region_name | ||
| + | FROM | ||
| + | hr.employees | ||
| + | left JOIN hr.departments ON employees.department_id = departments.department_id | ||
| + | left join hr.locations on departments.location_id = locations.location_id | ||
| + | left join hr.countries on locations.country_id = countries.country_id | ||
| + | left join hr.regions on countries.region_id = regions.region_id | ||
| + | where region_name = 'Europe' | ||
| + | </code> | ||
| + | |||
| + | <code> | ||
| + | SELECT | ||
| + | first_name, | ||
| + | last_name, | ||
| + | e.department_id aktuelle_department_id, | ||
| + | jh.department_id jh_department_id, | ||
| + | e.job_id aktuelle_job_id, | ||
| + | jh.job_id jh_job_id, | ||
| + | start_date, | ||
| + | end_date | ||
| + | FROM | ||
| + | employees e left JOIN job_history jh | ||
| + | ON e.employee_id = jh.employee_id | ||
| + | ORDER BY | ||
| + | coalesce(e.employee_id, jh.employee_id) | ||
| </code> | </code> | ||
kurs/joins.txt · Last modified: 2020/05/12 10:09 by admin
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