use appearancespost as foreign key

sql/load.sql

@@ -405,7 +405,7 @@ CREATE TABLE IF NOT EXISTS "battingpost" (
 	"SF"	NUMERIC,
 	"GIDP"	NUMERIC,
 	PRIMARY KEY("year","player","round"),
-	foreign key("player") references "people"("ID"),
+	foreign key("player","year") references "appearancespost"("player","year"),
 	foreign key("year","round") references "seriespost"("year","round")
 );
 
@@ -428,7 +428,7 @@ CREATE TABLE IF NOT EXISTS "fieldingpost" (
 	"SB"	NUMERIC,
 	"CS"	NUMERIC,
 	PRIMARY KEY("player","year","round","POS"),
-	foreign key("player") references "people"("ID"),
+	foreign key("player","year") references "appearancespost"("player","year"),
 	foreign key("year","round") references "seriespost"("year","round")
 );
 
@@ -464,7 +464,7 @@ CREATE TABLE IF NOT EXISTS "pitchingpost" (
 	"SF"	NUMERIC,
 	"GIDP"	NUMERIC,
 	PRIMARY KEY("player","year","round"),
-	foreign key("player") references "people"("ID"),
+	foreign key("player","year") references "appearancespost"("player","year"),
 	foreign key("year","round") references "seriespost"("year","round")
 );