Daha fazla join

Oracle SQL'ye Giriş

Sara Billen

Curriculum Manager

Diğer join türleri

CROSS JOIN
Kendine JOIN

Kartezyen çarpım (diğer adıyla cross product)

Kartezyen çarpım diyagramı

Tablolarda cross product

Cross product örneği

SELECT * 
FROM MediaType

| MediaTypeId | Name                        |
|-------------|-----------------------------|
| 1           | MPEG audio file             |
| 2           | Protected AAC audio file    |
| 3           | Protected MPEG-4 video file |
| 4           | Purchased AAC audio file    |
| 5           | AAC audio file              |

Cross product örneği

SELECT m.MediaTypeId, m.Name, t.TrackId, t.Name, t.MediaTypeId
FROM MediaType m CROSS JOIN Track t

| MediaTypeId | Name                        | TrackId | Name       | MediaTypeId       |
|-------------|-----------------------------|---------|------------|-------------------|
| 1           | MPEG audio file             | 3021    | Forty      | 1                 |
| 2           | Protected AAC audio file    | 3021    | Forty      | 1                 |
| 3           | Protected MPEG-4 video file | 3021    | Forty      | 1                 |
| 4           | Purchased AAC audio file    | 3021    | Forty      | 1                 |
| 5           | AAC audio file              | 3021    | Forty      | 1                 |

Kendine join

Bir tabloyu kendisiyle birleştirme

Kullanım durumu:

SELECT * FROM Employee

| EmployeeId | LastName | Title               | ... | ReportsTo |
|------------|----------|---------------------|-----|-----------|
| 1          | Adames   | General Manager     | ... | null      |
| 2          | Edwards  | Sales Manager       | ... | 1         |
| 3          | Peacock  | Sales Support Agent | ... | 2         |
| 4          | Park     | Sales Support Agent | ... | 2         |

Kendine join

SELECT e.LastName Employee, m.LastName ReportsTo
FROM Employee e JOIN Employee m
ON (e.ReportsTo = m.EmployeeId)

| Employee | ReportsTo |
|----------|-----------|
| Edwards  | Adams     |
| Peacock  | Edwards   |
| Mitchell | Adams     |
| Park       | Edwards   |
| ...      | ...       |

Haydi pratik yapalım!

Oracle SQL'ye Giriş