ERROR! A malformed block was encountered while loading tasks

[anandsolomon]

Hi,
I am new to ansible. I have installed oracle client, cx_oracle, ansible. But when running a playbook I am getting this below error.
ERROR! A malformed block was encountered while loading tasks: {u'environment': u'{{ oracle_env }}', u'oracle_sql': {u'username': u'{{ user }}', u'service_name': u'{{ service_name }}', u'password': u'{{ password }}', u'port': 1521, u'sql': u'select username from dba_users'}} should be a list or None but is <class 'ansible.parsing.yaml.objects.AnsibleMapping'>

The error appears to be in '/home/ansible/playbook/play4.yml': line 1, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

• hosts: DBServer
  ^ here

---------------------------Here is the playbook--------------------------

hosts: DBServer

vars:
oracle_home: /u01/app/oracle/product/12.2.0.1/dbhome_1
service_name: protegrity
set_init_mode: sysdba
set_init_user: sys
user: tstsch
password:
oracle_env:
ORACLE_HOME: "{{ oracle_home }}"
LD_LIBRARY_PATH: "{{ oracle_home }}/lib"
PATH: "/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:.:/u01/app/oracle/product/12.2.0.1/dbhome_1/bin"

tasks:
oracle_sql:
username: "{{ user }}"
password: "{{ password }}"
port: 1521
service_name: "{{ service_name }}"
sql: "select username from dba_users"

environment: "{{ oracle_env }}"

[anandsolomon]

I am able resolve this.