This tutorial introduces the notion of a join. The database consists of three tables movie , actor and casting .
movie | actor | casting |
|---|
| id |
id |
movieid |
| title |
name |
actorid |
| yr |
|
ord |
| director |
|
|
| budget |
|
|
| gross |
|
|
| |
|
|
movie
| Field name | Type | Notes |
|---|
| id |
INTEGER |
An arbitrary unique identifier |
| title |
CHAR(70) |
The name of the film - usually in the language of the first release. |
| yr |
DECIMAL(4) |
Year of first release. |
| director |
INT |
A reference to the actor table. |
| budget |
INTEGER |
How much the movie cost to make (in a variety of currencies unfortunately). |
| gross |
INTEGER |
How much the movie made at the box office. |
Example
| id | title | yr | director | budget | gross |
|---|
| 10003 |
"Crocodile" Dundee II |
1988 |
38 |
15800000 |
239606210 |
| 10004 |
‘Til There Was You |
1997 |
49 |
10000000 |
|
actor
| Field name | Type | Notes |
|---|
| id |
INTEGER |
An arbitrary unique identifier |
| name |
CHAR(36) |
The name of the actor (the term actor is used to refer to both male and female thesps.) |
Example
| id | name |
|---|
| 20 |
Paul Hogan |
| 50 |
Jeanne Tripplehorn |
casting
| Field name | Type | Notes |
|---|
| movieid |
INTEGER |
A reference to the movie table. |
| actorid |
INTEGER |
A reference to the actor table. |
| ord |
INTEGER |
The ordinal position of the actor in the cast list. The
star of the movie will have ord value 1 the co-star will have
value 2, ... |
Example
| movieid | actorid | ord |
|---|
| 10003 |
20 |
4 |
| 10004 |
50 |
1 |
mysql练习----More JOIN operations
原文：http://www.cnblogs.com/tk55/p/6759749.html
