Соединение таблиц

 ALTER TABLE kassy ADD CONSTRAINT fk_kassyShops FOREIGN KEY (shops) REFERENCES shops(name) 
 
 
CREATE TABLE "KASSY"
  (
    "ID"   VARCHAR2(20 BYTE),
    "SHOP" VARCHAR2(20 BYTE),
    CONSTRAINT "PK_KASSY" PRIMARY KEY ("ID") 
    CONSTRAINT "UQ_KASSY" UNIQUE ("ID", "SHOP")
  )
 
 
CREATE TABLE "SHOPS"
  (
    "ID"     VARCHAR2(20 BYTE),
    "NAME"   VARCHAR2(20 BYTE),
    "ADRESS" VARCHAR2(20 BYTE),
    CONSTRAINT "PK_SHOP" PRIMARY KEY ("ID") 
  )
 
 
CREATE TABLE "OPERATIONS"
  (
    "ID"        NUMBER,
    "TYPE_OPER" VARCHAR2(20 BYTE),
    "AMOUNT"    VARCHAR2(20 BYTE),
    "CUR"       VARCHAR2(10 BYTE),
    "DATA_OPER" VARCHAR2(20 BYTE),
    "AM_REAL"   VARCHAR2(30 BYTE),
    "CARD_ID"   VARCHAR2(20 BYTE),
    "SHOP"      VARCHAR2(20 BYTE),
    "KASSY"     VARCHAR2(20 BYTE),
    CONSTRAINT "PK_OPER" PRIMARY KEY ("ID") 
  )

ALTER TABLE kassy ADD CONSTRAINT fk_kassyShops FOREIGN KEY (SHOP) REFERENCES SHOPS(ID);