create table GURU (
NIG VARCHAR2(32) not null,
NAMA VARCHAR2(64) not null,
JENIS_KELAMIN CHAR not null,
TGL_MASUK DATE,
STATUS_PEG CHAR not null,
constraint PK_GURU primary key (NIG))

create table KELAS (
KELAS_ID VARCHAR2(32) not null,
KETERANGAN VARCHAR2(64),
constraint PK_KELAS primary key (KELAS_ID))

create table MATA_PELAJARAN (
KODE_MP VARCHAR(32) not null,
NAMA_MP VARCHAR(64) not null,
KREDIT NUMBER not null,
constraint PK_MATA_PELAJARAN primary key (KODE_MP))

create table MURID (
NIS VARCHAR2(32) not null,
KELAS_ID VARCHAR2(32) not null,
NAMA VARCHAR2(64) not null,
TGL_LAHIR DATE not null,
JENIS_KELAMIN CHAR not null,
ALAMAT VARCHAR2(128) not null,
NAMA_ORTU VARCHAR2(64),
constraint PK_MURID primary key (NIS),
constraint AK_MURID unique (KELAS_ID, NIS),
constraint MURID#KELAS_FK foreign key (KELAS_ID) references KELAS (KELAS_ID))

create table ULANGAN (
NIS VARCHAR2(32) not null,
KODE_MP VARCHAR2(32) not null,
UJIAN_KE NUMBER not null,
TGL_UJIAN DATE not null,
NILAI NUMBER,
constraint PK_ULANGAN primary key (NIS, KODE_MP, UJIAN_KE),
constraint ULANGAN#MURID_FK foreign key (NIS) references MURID (NIS),
constraint ULANGAN#MATA_PELAJARAN_FK foreign key (KODE_MP) references MATA_PELAJARAN (KODE_MP))

create table BELAJAR (
NIG VARCHAR2(32) not null,
KODE_MP VARCHAR2(32) not null,
KELAS_ID VARCHAR2(32) not null,
HARI VARCHAR2(32) not null,
constraint PK_BELAJAR primary key (NIG, KODE_MP, KELAS_ID),
constraint BELAJAR#GURU_FK foreign key (NIG) references GURU (NIG),
constraint BELAJAR#MATA_PELAJARAN_FK foreign key (KODE_MP) references MATA_PELAJARAN (KODE_MP),
constraint BELAJAR#KELAS_FK foreign key (KELAS_ID) references KELAS (KELAS_ID))