4D Doc Center : SQLコードから4Dメソッドを呼び出す

4D v14

SQLコードから4Dメソッドを呼び出す

ここでは、映画ごとに出演者に関する何らかの情報を取得します。たとえば最低7人の出演者がいる映画を探すといったようなものです。結果は年で並び替えられます。
これを行うために、4Dメソッド (Find_Nr_Of_Actors) を使用します。このメソッドは映画のIDを受け取り、その映画の出演者数を返します:

  `(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])

4Dコードは以下のようになります:

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;>)

SQLコードの場合:

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

ここで示すとおり、SQLコード内部で以下のシンタックスを使用することにより4Dメソッドを呼び出すことができます:

{fn 4DFunctionName AS 4DFunctionResultType}

汎用SQLコマンドの場合:

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

QUERY BY SQLコマンドの場合:

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;>)

SQLのEXECUTE IMMEDIATEコマンドの場合:

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

これらをテストするには"4D SQL Code Samples"データベースを起動してメインウィンドウを表示させます。クエリモードを選択して Calling 4D methodsボタンをクリックします。