PRAGMA foreign_keys = ON;

PRAGMA writable_schema = 1;
DELETE FROM sqlite_master WHERE type IN ("table", "index", "trigger");
PRAGMA writable_schema = 0;
VACUUM;

CREATE TABLE "concert" (
"concert_ID" INT UNIQUE,
PRIMARY KEY ("concert_ID")
);

CREATE TABLE "singer" (
"Singer_ID" INT UNIQUE,
PRIMARY KEY ("Singer_ID")
);

CREATE TABLE "singer_in_concert" (
"concert_ID" INT,
"Singer_ID" TEXT,
PRIMARY KEY ("concert_ID", "Singer_ID"),
FOREIGN KEY ("concert_ID") REFERENCES "concert"("concert_ID"),
FOREIGN KEY ("Singer_ID") REFERENCES "singer"("Singer_ID")
);





INSERT INTO "concert" VALUES ("1");
INSERT INTO "concert" VALUES ("2");
INSERT INTO "concert" VALUES ("3");
INSERT INTO "concert" VALUES ("4");
INSERT INTO "concert" VALUES ("5");
INSERT INTO "singer" VALUES ("1");
INSERT INTO "singer" VALUES ("2");
INSERT INTO "singer" VALUES ("3");
INSERT INTO "singer" VALUES ("4");
INSERT INTO "singer" VALUES ("5");
INSERT INTO "singer" VALUES ("6");
INSERT INTO "singer" VALUES ("7");
INSERT INTO "singer_in_concert" VALUES ("1", "1");
INSERT INTO "singer_in_concert" VALUES ("1", "2");
INSERT INTO "singer_in_concert" VALUES ("2", "3");
INSERT INTO "singer_in_concert" VALUES ("2", "4");
INSERT INTO "singer_in_concert" VALUES ("3", "1");
INSERT INTO "singer_in_concert" VALUES ("3", "5");
INSERT INTO "singer_in_concert" VALUES ("4", "6");
INSERT INTO "singer_in_concert" VALUES ("5", "7");