The database is really a many-to-many relation between MOVIE and ACTOR. CASTING is an intermediate entity type which is present only to allow the many-to-many relationship to be implemented.
The SELECT is good, and the query uses all three tables. However, there is only one JOIN (there should be two), and no search for the data 1959.
The database is really a many-to-many relation between MOVIE and ACTOR. CASTING is an intermediate entity type which is present only to allow the many-to-many relationship to be implemented.
The SELECT is good, but the query uses only two tables (not three), missing out the intermediate entity type which supports the many-to-many relationship. In addition, there are no JOINs (there should be two).
The database is really a many-to-many relation between MOVIE and ACTOR. CASTING is an intermediate entity type which is present only to allow the many-to-many relationship to be implemented.
The SELECT is good, and the query uses all three tables. There are two JOINs, and all the search criteria are present.
The database is really a many-to-many relation between MOVIE and ACTOR. CASTING is an intermediate entity type which is present only to allow the many-to-many relationship to be implemented.
The SELECT is good, and the query uses all three tables. However, there is a JOIN involving movie.yr == casting.yr, yet there is you yr in CASTING. The searches look right though.
The database is really a many-to-many relation between MOVIE and ACTOR. CASTING is an intermediate entity type which is present only to allow the many-to-many relationship to be implemented.
We are looking for a SELECT which uses all three tables, as we need MOVIE for the title and year, ACTOR for Marilyn Monroe, and CASTING to support the relationship between them. We need two joins; ACTOR-CASTING and CASTING-MOVIE. We also need two search conditions; one for Marilyn Monroe, and the other for the year. Look again at the other options...
Films Database
Consider the following database:
MOVIE(id,title,yr)
ACTOR(id,name)
CASTING(movieid,actorid)
The following SQL... SELECT title FROM movie,casting,actor WHERE movieid = movie.id AND name = 'Marilyn Monroe' ;The following SQL... SELECT title FROM movie,actor WHERE name = 'Marilyn Monroe' AND yr = 1959 ;The following SQL... SELECT title FROM movie,casting,actor WHERE movieid = movie.id AND actor.id = actorid AND name = 'Marilyn Monroe' AND yr = 1959 ;The following SQL... SELECT title FROM movie,casting,actor WHERE movieid = movie.id AND actor.id = actorid AND movie.yr = casting.yr AND name = 'Marilyn Monroe' AND yr = 1959 ;- None of the above
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