4D Doc Center : Chamar os métodos 4D desde o código SQL

4D v14

Chamar os métodos 4D desde o código SQL

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:

  `(F) Find_Nr_Of_Actors

 C_LONGINT($0;$1;$vMovie_ID)

 $vMovie_ID:=$1

 

 QUERY([MOVIE_ACTOR];[MOVIE_ACTOR]Movie_ID=$vMovie_ID)

 $0:=Records in selection([MOVIE_ACTOR])

O código 4D inicial seria:

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 $NrOfActors:=7 ALL RECORDS([MOVIES]) For($i;1;Records in selection([MOVIES])) $vCrtActors:=Find_Nr_Of_Actors([MOVIES]ID) If($vCrtActors>=$NrOfActors) $vInd:=$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}:=$vCrtActors End if NEXT RECORD([MOVIES]) End for SORT ARRAY(aMovieYear;aTitles;aDirectors;aMedias;aSoldTickets;aNrActors;>)

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.