5.1. .
1.
2.
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- (renaming) .
ᒺ (.5.1).
R, S , :
- , () ;
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- ( , ).
title | year | length | filmtype | studioName | starName |
Star Wrs | Color | Fox | Carrie Fisher | ||
Waynes World | Color | Paramount | Mike Meyers |
|
|
³ R
title | year | length | filmtype | studioName | starName |
Star Wrs | Color | Fox | Carrie Fisher | ||
Mighty Ducks | Color | Disney | Emilio Estevez | ||
Waynes World | Color | Paramount | Mike Meyers |
³ S
title | year | length | filmtype | studioName | starName |
Star Wrs | Color | Fox | Carrie Fisher | ||
Mighty Ducks | Color | Disney | Emilio Estevez | ||
Waynes World | Color | Paramount | Mike Meyers |
.5.1. ᒺ R S
³, , Գ .
R ∩ S. .5.2
title | year | length | filmtype | studioName | starName |
Star Wrs | Color | Fox | Carrie Fisher | ||
Waynes World | Color | Paramount | Mike Meyers |
. 5.2. R S
S-R. .5.3.
title | year | length | filmtype | studioName | starName |
Mighty Ducks | Color | Disney | Emilio Estevez |
. 5.3. г S R
, .
title | year | length | InColor | studioName | producerC# |
Star Wrs | true | Fox | |||
Mighty Ducks | true | Disney | |||
Waynes World | true | Paramount |
D
title | year | length |
Star Wrs | ||
Mighty Ducks | ||
Waynes World |
.5.4. D
5.1. D (.5.4), .
ptitle, year, length (D)
.
, , D , D, C, D. s(D).
, . , , D. t D, , , t. , t s(D); t .
5.2. ³, slength ³100(D), .5.5.
|
|
title | year | length | InColor | studioName | producerC# |
Star Wrs | true | Fox | |||
Mighty Ducks | true | Disney |
.5.5. ³ slength ³100(D)
.5.5., D (.5.4.) length ³ 100. , 1 2 D .
.
, R S. R S , . , . : R, S. R S ᒺ R S. , R S , . R. S..
D | |||||
³ R ³ S
A | R.B | S.B | C | D |
.5.6. ³ R S
璺.
璺 R S (natural join) R S R S, , R S. 璺 R S, . 5.6, .5.7.
A | B | C | D |
.5.7. 璺 R S (.5.6.)
, R S.
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- R S;
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R S
5.3. - R S.
R S
(A+C)³D
R S .5.6. - .5.8.
A | R.B | S.B | C | D |
.5.8. - 5.3.
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.
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5.4.
|
|
䳿 Fox, 100 . :
- Movie , length³100
- Movie ,
studioName=Fox;
- , ..1,2;
- .3 title year.
2. (.5.9), (π - , σ- , ∩ - )
.5.9
3. :
ptitle, year (σ length≧100 (Movie) ∩ σ studioName = Fox (Movie))
(AND)
ptitle, year (σ length≧100 AND σ studioName = Fox (Movie))