CREATE TABLE PROF_BUS (PROF VARCHAR2(20)  , PRIMARY KEY (PROF));
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CREATE TABLE PROF_GOV (PROF VARCHAR2(20)  , PRIMARY KEY (PROF));
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CREATE TABLE TOWN ( AREACODE VARCHAR2(2) , AREA VARCHAR2(20) , PRIMARY KEY(AREACODE,AREA));
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CREATE TABLE EDIS_RES (AREACODE VARCHAR2(2) , TELNO NUMBER(9) , NAME1 VARCHAR2(100) ,
 NAME2 VARCHAR2(100) , NAME3 VARCHAR2(100) , NAME4 VARCHAR2(100) , GOV_NAM VARCHAR2(20),primary key(TELNO));
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CREATE TABLE EDIS_BUS (AREACODE VARCHAR2(2) , TELNO NUMBER(9) , NAME1 VARCHAR2(100) ,
 NAME2 VARCHAR2(100) , GOV_NAM VARCHAR2(20),primary key(TELNO));
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CREATE TABLE EDIS_GOV (AREACODE VARCHAR2(2) , TELNO NUMBER(9) , NAME1 VARCHAR2(100) ,
 NAME2 VARCHAR2(100) , GOV_NAM VARCHAR2(20),primary key(TELNO));
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ALTER TABLE EDIS_RES ADD CONSTRAINT FK_EDIS_RES_TOWN FOREIGN KEY(AREACODE,GOV_NAM) 
REFERENCES TOWN(AREACODE,AREA);
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ALTER TABLE EDIS_BUS ADD CONSTRAINT FK_EDIS_BUS_TOWN FOREIGN KEY(AREACODE,GOV_NAM) 
REFERENCES TOWN(AREACODE,AREA);
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ALTER TABLE EDIS_GOV ADD CONSTRAINT FK_EDIS_GOV_PROF FOREIGN KEY(AREACODE,GOV_NAM) 
REFERENCES TOWN(AREACODE,AREA);
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ALTER TABLE EDIS_GOV ADD CONSTRAINT FK_EDIS_GOV_PROF FOREIGN KEY(NAME1) 
REFERENCES PROF_GOV(PROF);
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ALTER TABLE EDIS_BUS ADD CONSTRAINT FK_EDIS_BUS_PROF FOREIGN KEY(NAME1) 
REFERENCES PROF_BUS(PROF);
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