Agora queremos realizar pesquisas relativas aos atores de cada filme: especificamente, estamos interessados em encontrar todas os filmes com pelo menos 7 atores. O resultado será ordenado por ano.
Para fazer isto, utilizamos uma função 4D (Find_Nr_Of_Actors) que recebe o ID do filme e devolve o número de atores do filme:
C_LONGINT($0;$1;$vMovie_ID)
$vMovie_ID:=$1
QUERY([MOVIE_ACTOR];[MOVIE_ACTOR]Movie_ID=$vMovie_ID)
$0:=Records in selection([MOVIE_ACTOR])
- Utilizando código SQL:
ARRAY LONGINT(aSoldTickets;0)
ARRAY INTEGER(aMovieYear;0)
ARRAY LONGINT(aNrActors;0)
ARRAY TEXT(aTitles;0)
ARRAY TEXT(aDirectors;0)
ARRAY TEXT(aMedias;0)
C_LONGINT($NrOfActors;$i;$vInd)
$vInd:=0
$NrOfActors:=7
Begin SQL
SELECT Year_of_Movie, Title, Director, Media, Sold_Tickets, {fn Find_Nr_Of_Actors(ID) AS NUMERIC}
FROM MOVIES
WHERE {fn Find_Nr_Of_Actors(ID) AS NUMERIC} >= :$NrOfActors
ORDER BY 1
INTO :aMovieYear, :aTitles, :aDirectors, :aMedias, :aSoldTickets, :aNrActors;
End SQL
Pode ver que podemos chamar a uma função 4D dentro do código SQL utilizando a sintaxes:
{fn 4DFunctionName AS 4DFunctionResultType}
- Utilizando comandos SQL genéricos:
ARRAY LONGINT(aSoldTickets;0)
ARRAY INTEGER(aMovieYear;0)
ARRAY LONGINT(aNrActors;0)
ARRAY TEXT(aTitles;0)
ARRAY TEXT(aDirectors;0)
ARRAY TEXT(aMedias;0)
C_LONGINT($NrOfActors;$i;$vInd)
C_TEXT($tQueryTxt)
$vInd:=0
$NrOfActors:=7
SQL LOGIN(SQL_INTERNAL;"";"")
$tQueryTxt:=""
$tQueryTxt:=$tQueryTxt+"SELECT Year_of_Movie, Title, Director, Media, Sold_Tickets, {fn Find_Nr_Of_Actors(ID) AS NUMERIC}"
$tQueryTxt:=$tQueryTxt+" FROM MOVIES"
$tQueryTxt:=$tQueryTxt+" WHERE {fn Find_Nr_Of_Actors(ID) AS NUMERIC} >= :$NrOfActors"
$tQueryTxt:=$tQueryTxt+" ORDER BY 1"
SQL EXECUTE($tQueryTxt;aMovieYear;aTitles;aDirectors;aMedias;aSoldTickets;aNrActors)
SQL LOAD RECORD(SQL all records)
SQL LOGOUT
- Utilizando o comando QUERY BY SQL:
ARRAY LONGINT(aSoldTickets;0)
ARRAY INTEGER(aMovieYear;0)
ARRAY LONGINT(aNrActors;0)
ARRAY TEXT(aTitles;0)
ARRAY TEXT(aDirectors;0)
ARRAY TEXT(aMedias;0)
C_LONGINT($NrOfActors;$i;$vInd)
$vInd:=0
$NrOfActors:=7
QUERY BY SQL([MOVIES];"{fn Find_Nr_Of_Actors(ID) AS NUMERIC} >= :$NrOfActors")
For($i;1;Records in selection([MOVIES]))
$vInd:=$vInd+1
INSERT IN ARRAY(aMovieYear;$vInd;1)
aMovieYear{$vInd}:=[MOVIES]Year_of_Movie
INSERT IN ARRAY(aTitles;$vInd;1)
aTitles{$vInd}:=[MOVIES]Title
INSERT IN ARRAY(aDirectors;$vInd;1)
aDirectors{$vInd}:=[MOVIES]Director
INSERT IN ARRAY(aMedias;$vInd;1)
aMedias{$vInd}:=[MOVIES]Media
INSERT IN ARRAY(aSoldTickets;$vInd;1)
aSoldTickets{$vInd}:=[MOVIES]Sold_Tickets
INSERT IN ARRAY(aNrActors;$vInd;1)
aNrActors{$vInd}:=Find_Nr_Of_Actors([MOVIES]ID)
NEXT RECORD([MOVIES])
End for
SORT ARRAY(aMovieYear;aTitles;aDirectors;aMedias;aSoldTickets;aNrActors;>)
- Utilizando o comando SQL EXECUTE IMMEDIATE:
ARRAY LONGINT(aSoldTickets;0)
ARRAY INTEGER(aMovieYear;0)
ARRAY LONGINT(aNrActors;0)
ARRAY TEXT(aTitles;0)
ARRAY TEXT(aDirectors;0)
ARRAY TEXT(aMedias;0)
C_LONGINT($NrOfActors;$i;$vInd)
C_TEXT($tQueryTxt)
$vInd:=0
$NrOfActors:=7
$tQueryTxt:=""
$tQueryTxt:=$tQueryTxt+"SELECT Year_of_Movie, Title, Director, Media, Sold_Tickets, {fn Find_Nr_Of_Actors(ID) AS NUMERIC}"
$tQueryTxt:=$tQueryTxt+" FROM MOVIES"
$tQueryTxt:=$tQueryTxt+" WHERE {fn Find_Nr_Of_Actors(ID) AS NUMERIC} >= :$NrOfActors"
$tQueryTxt:=$tQueryTxt+" ORDER BY 1"
$tQueryTxt:=$tQueryTxt+" INTO :aMovieYear, :aTitles, :aDirectors, :aMedias, :aSoldTickets,"+" :aNrActors;"
Begin SQL
EXECUTE IMMEDIATE :$tQueryTxt;
End SQL
Para provar todos os exemplos anteriores, lance a base "4D SQL Code Samples" e vá até a janela principal. A continuação, pode escolher o modo de pesquisa e pressionar o botão Calling 4D methods.