CSV data load has some problem to insert data into postgres database

step1:

CREATE TABLE jcp_event
(
jcp_event_id bigint NOT NULL,
event_name character varying(200) NOT NULL,
event_type character varying(20),
event_desc character varying(200),
event_status character varying(3),
event_display_name character varying(50),
parent_event_id bigint,
last_archival_date date,
creation_date date NOT NULL,
created_by bigint NOT NULL,
update_date date NOT NULL,
updated_by bigint NOT NULL,
CONSTRAINT jcp_event_pk PRIMARY KEY (jcp_event_id)
)

step2:

am trying to insert data using csv file ,but in the above table "parent_event_id" is nullable column so that i did't put any value for this but while executing this below changeset it is throwing below exception

Changeset:

<changeSet id="716" author="jaws">
<comment>Inserting JCP_EVENT seed data . . .</comment>
<loadData tableName="JCP_EVENT" file="liquibasedb/Seeddata_Updation/JCP_EVENT_LOGINMODULE.csv"/>
</changeSet>

Exception:
invalid input syntax for integer: ""

please find the attachement
Is there a way to short out this problem ,this is happening only for postgresql ,same thing working fine for oracle.