ansible complex string example proof for https://stackoverflow.com/a/56234698/9401096

A_test_with_value.yml

---
- name: complex string
  hosts: localhost
  gather_facts: false

  vars:
    DATABASE_LISTDELETED_RESOURCEGROUP: my_ressource_group
    DATABASE_LISTDELETED_SQLSERVER: my_sql_server
    DATABASE_LISTDELETED_QUERY: this is a line of text which mimics an actual query I don't have

  tasks:
    - name: Store my command in a var
      set_fact:
        my_command: >-
          az sql db list-deleted
          --resource-group "{{ DATABASE_LISTDELETED_RESOURCEGROUP }}"
          --server "{{ DATABASE_LISTDELETED_SQLSERVER }}"
          {% if DATABASE_LISTDELETED_QUERY is defined %}
          --query "{{ DATABASE_LISTDELETED_QUERY }}"
          {% endif %}
          --output json
    - debug:
        var: my_command

B_result_with_value.txt

PLAY [complex string] **********************************************************

TASK [Store my command in a var] ***********************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "my_command": "az sql db list-deleted --resource-group \"my_ressource_group\" --server \"my_sql_server\"  --query \"this is a line of text which mimics an actual query I don't have\"  --output json"
}

PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0 

C_test_without_value.yml

---
- name: complex string
  hosts: localhost
  gather_facts: false

  vars:
    DATABASE_LISTDELETED_RESOURCEGROUP: my_ressource_group
    DATABASE_LISTDELETED_SQLSERVER: my_sql_server

  tasks:
    - name: Store my command in a var
      set_fact:
        my_command: >-
          az sql db list-deleted
          --resource-group "{{ DATABASE_LISTDELETED_RESOURCEGROUP }}"
          --server "{{ DATABASE_LISTDELETED_SQLSERVER }}"
          {% if DATABASE_LISTDELETED_QUERY is defined %}
          --query "{{ DATABASE_LISTDELETED_QUERY }}"
          {% endif %}
          --output json
    - debug:
        var: my_command

D_result_without_value.txt

PLAY [complex string] **********************************************************

TASK [Store my command in a var] ***********************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "my_command": "az sql db list-deleted --resource-group \"my_ressource_group\" --server \"my_sql_server\"  --output json"
}

PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0