error in SELECT

CREATE TABLE public.students (
  id INTEGER PRIMARY KEY NOT NULL DEFAULT nextval('students_id_seq'::regclass),
  first_name CHARACTER VARYING(20) NOT NULL,
  last_name CHARACTER VARYING(20) NOT NULL,
  major CHARACTER VARYING(20) NOT NULL
);
CREATE UNIQUE INDEX "Students_ID_uindex" ON students USING BTREE (id);

SELECT * FROM public.students;

---------------------------
[2016-03-12 22:16:54] Run postgres.public.students [PostgreSQL - postgres@localhost]
[2016-03-12 22:16:54] Connecting to PostgreSQL - postgres@localhost...
CREATE TABLE public.students (
  id INTEGER PRIMARY KEY NOT NULL DEFAULT nextval('students_id_seq'::regclass),
  first_name CHARACTER VARYING(20) NOT NULL,
  last_name CHARACTER VARYING(20) NOT NULL,
  major CHARACTER VARYING(20) NOT NULL
)
[2016-03-12 22:16:54] [42P07] ERROR: relation "students" already exists
CREATE UNIQUE INDEX "Students_ID_uindex" ON students USING BTREE (id)
[2016-03-12 22:16:54] [42P07] ERROR: relation "Students_ID_uindex" already exists
SELECT * FROM public.students
[2016-03-12 22:16:54] Executed in 14ms ms

[2016-03-12 22:16:54] Summary: 3 of 3 statements executed, 2 failed in 68ms (338 symbols in file)