
  CREATE TABLE "EMPLOYEES" 
   (	"EMPLOYEE_ID" NUMBER(6,0), 
	"FIRST_NAME" VARCHAR2(20), 
	"LAST_NAME" VARCHAR2(25) CONSTRAINT "EMP_LAST_NAME_NN" NOT NULL ENABLE, 
	"EMAIL" VARCHAR2(25) CONSTRAINT "EMP_EMAIL_NN" NOT NULL ENABLE, 
	"PHONE_NUMBER" VARCHAR2(20), 
	"HIRE_DATE" DATE CONSTRAINT "EMP_HIRE_DATE_NN" NOT NULL ENABLE, 
	"JOB_ID" VARCHAR2(10) CONSTRAINT "EMP_JOB_NN" NOT NULL ENABLE, 
	"SALARY" NUMBER(8,2), 
	"COMMISSION_PCT" NUMBER(2,2), 
	"MANAGER_ID" NUMBER(6,0), 
	"DEPARTMENT_ID" NUMBER(4,0), 
	 CONSTRAINT "EMP_SALARY_MIN" CHECK (salary > 0) ENABLE, 
	 CONSTRAINT "EMP_EMAIL_UK" UNIQUE ("EMAIL")
  USING INDEX  ENABLE, 
	 CONSTRAINT "EMP_DEPT_FK" FOREIGN KEY ("DEPARTMENT_ID")
	  REFERENCES "DEPARTMENTS" ("DEPARTMENT_ID") ENABLE, 
	 CONSTRAINT "EMP_JOB_FK" FOREIGN KEY ("JOB_ID")
	  REFERENCES "JOBS" ("JOB_ID") ENABLE, 
	 CONSTRAINT "EMP_MANAGER_FK" FOREIGN KEY ("MANAGER_ID")
	  REFERENCES "EMPLOYEES" ("EMPLOYEE_ID") ENABLE
   ) ;
  CREATE UNIQUE INDEX "EMP_EMP_ID_PK" ON "EMPLOYEES" ("EMPLOYEE_ID") 
  ;
ALTER TABLE "EMPLOYEES" ADD CONSTRAINT "EMP_EMP_ID_PK" PRIMARY KEY ("EMPLOYEE_ID")
  USING INDEX "EMP_EMP_ID_PK"  ENABLE;