sql tables cant be imported for unknown reason - sql

Question

my tables don't want to be imported from vertabelo and I honestly don't know why. I'm using an oracle connection. if someone could give me a hand with it, it would be kind of you. I'll provide the code below with the errors it's giving. tables equipment, coach and rent are working. however, tables customer and training cant be imported and I honestly don't know what to do.
-- tables
-- Table: coach
CREATE TABLE coach (
id integer NOT NULL,
first_name varchar(255) NOT NULL,
second_name varchar(255) NOT NULL,
CONSTRAINT coach_pk PRIMARY KEY (id)
);
-- Table: customer
CREATE TABLE customer (
id int NOT NULL,
first_name Varchar(55) NOT NULL,
second_name Varchar(55) NOT NULL,
birth_date DateTime NULL,
skill_level int NOT NULL,
CONSTRAINT customer_pk PRIMARY KEY (id)
);
-- Table: equipment
CREATE TABLE equipment (
id int NOT NULL,
price int NOT NULL,
name_of_equipment int NOT NULL,
category_of_equipment int NOT NULL,
CONSTRAINT equipment_pk PRIMARY KEY (id)
);
-- Table: rent
CREATE TABLE rent (
equipment_id int NOT NULL,
customer_id int NOT NULL,
number_of_days date NOT NULL,
CONSTRAINT rent_pk PRIMARY KEY (number_of_days)
);
-- Table: training
CREATE TABLE training (
coach_id int NOT NULL,
customer_id int NOT NULL,
training_time_start time NOT NULL,
training_time_end time NOT NULL,
training_place_id int NOT NULL,
CONSTRAINT training_pk PRIMARY KEY (training_place_id)
);
-- foreign keys
-- Reference: rent_customer (table: rent)
ALTER TABLE rent ADD CONSTRAINT rent_customer FOREIGN KEY rent_customer (customer_id)
REFERENCES customer (id);
-- Reference: rent_equipment (table: rent)
ALTER TABLE rent ADD CONSTRAINT rent_equipment FOREIGN KEY rent_equipment (equipment_id)
REFERENCES equipment (id);
-- Reference: training_coach (table: training)
ALTER TABLE training ADD CONSTRAINT training_coach FOREIGN KEY training_coach (coach_id)
REFERENCES coach (id);
-- Reference: training_customer (table: training)
ALTER TABLE training ADD CONSTRAINT training_customer FOREIGN KEY training_customer (customer_id)
REFERENCES customer (id);
Error starting at line : 3 in command -
CREATE TABLE coach (
id integer NOT NULL,
first_name varchar(255) NOT NULL,
second_name varchar(255) NOT NULL,
CONSTRAINT coach_pk PRIMARY KEY (id)
)
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 - "name is already used by an existing object"
*Cause:
*Action:
Error starting at line : 11 in command -
CREATE TABLE customer (
id int NOT NULL,
first_name Varchar(55) NOT NULL,
second_name Varchar(55) NOT NULL,
birth_date DateTime NULL,
skill_level int NOT NULL,
CONSTRAINT customer_pk PRIMARY KEY (id)
)
Error report -
ORA-00902: invalid datatype
00902. 00000 - "invalid datatype"
*Cause:
*Action:
Error starting at line : 21 in command -
CREATE TABLE equipment (
id int NOT NULL,
price int NOT NULL,
name_of_equipment int NOT NULL,
category_of_equipment int NOT NULL,
CONSTRAINT equipment_pk PRIMARY KEY (id)
)
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 - "name is already used by an existing object"
*Cause:
*Action:
Error starting at line : 30 in command -
CREATE TABLE rent (
equipment_id int NOT NULL,
customer_id int NOT NULL,
number_of_days date NOT NULL,
CONSTRAINT rent_pk PRIMARY KEY (number_of_days)
)
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 - "name is already used by an existing object"
*Cause:
*Action:
Error starting at line : 38 in command -
CREATE TABLE training (
coach_id int NOT NULL,
customer_id int NOT NULL,
training_time_start time NOT NULL,
training_time_end time NOT NULL,
training_place_id int NOT NULL,
CONSTRAINT training_pk PRIMARY KEY (training_place_id)
)
Error report -
ORA-00902: invalid datatype
00902. 00000 - "invalid datatype"
*Cause:
*Action:
Error starting at line : 49 in command -
ALTER TABLE rent ADD CONSTRAINT rent_customer FOREIGN KEY rent_customer (customer_id)
REFERENCES customer (id)
Error report -
ORA-00906: missing left parenthesis
00906. 00000 - "missing left parenthesis"
*Cause:
*Action:
Error starting at line : 53 in command -
ALTER TABLE rent ADD CONSTRAINT rent_equipment FOREIGN KEY rent_equipment (equipment_id)
REFERENCES equipment (id)
Error report -
ORA-00906: missing left parenthesis
00906. 00000 - "missing left parenthesis"
*Cause:
*Action:
Error starting at line : 57 in command -
ALTER TABLE training ADD CONSTRAINT training_coach FOREIGN KEY training_coach (coach_id)
REFERENCES coach (id)
Error report -
ORA-00906: missing left parenthesis
00906. 00000 - "missing left parenthesis"
*Cause:
*Action:
Error starting at line : 61 in command -
ALTER TABLE training ADD CONSTRAINT training_customer FOREIGN KEY training_customer (customer_id)
REFERENCES customer (id)
Error report -
ORA-00906: missing left parenthesis
00906. 00000 - "missing left parenthesis"
*Cause:
*Action: