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 "course" (
"Course_ID" INT,
"Course" TEXT,
PRIMARY KEY ("Course_ID")
);

CREATE TABLE "course_arrange" (
"Course_ID" INT,
"Teacher_ID" INT,
"Grade" INT,
PRIMARY KEY ("Course_ID", "Teacher_ID", "Grade"),
FOREIGN KEY ("Teacher_ID") REFERENCES "teacher"("Teacher_ID")
);

CREATE TABLE "teacher" (
"Teacher_ID" INT UNIQUE,
"Age" TEXT,
"Hometown" TEXT,
PRIMARY KEY ("Teacher_ID")
);





INSERT INTO "course" VALUES ("1", "Mathematics");
INSERT INTO "course" VALUES ("2", "Physics");
INSERT INTO "course" VALUES ("3", "Chemistry");
INSERT INTO "course" VALUES ("4", "Biology");
INSERT INTO "course" VALUES ("5", "History");
INSERT INTO "teacher" VALUES ("101", "29", "New York");
INSERT INTO "teacher" VALUES ("102", "35", "Los Angeles");
INSERT INTO "teacher" VALUES ("103", "22", "Chicago");
INSERT INTO "teacher" VALUES ("104", "40", "Houston");
INSERT INTO "teacher" VALUES ("105", "22", "San Francisco");
INSERT INTO "teacher" VALUES ("106", "30", "Seattle");
INSERT INTO "course_arrange" VALUES ("1", "101", "10");
INSERT INTO "course_arrange" VALUES ("2", "102", "11");
INSERT INTO "course_arrange" VALUES ("3", "103", "12");
INSERT INTO "course_arrange" VALUES ("4", "104", "10");
INSERT INTO "course_arrange" VALUES ("5", "105", "11");
INSERT INTO "course_arrange" VALUES ("1", "106", "12");
INSERT INTO "course_arrange" VALUES ("2", "103", "10");
INSERT INTO "course_arrange" VALUES ("3", "105", "12");
INSERT INTO "course_arrange" VALUES ("4", "101", "11");
INSERT INTO "course_arrange" VALUES ("5", "106", "10");