{% macro union_data(table_identifier, database_variable, schema_variable, default_database, default_schema, default_variable) -%}

{{ adapter.dispatch('union_data', packages = fivetran_utils._get_utils_namespaces()) (table_identifier, database_variable, schema_variable, default_database, default_schema, default_variable) }}

{%- endmacro %}

{% macro default__union_data(table_identifier, database_variable, schema_variable, default_database, default_schema, default_variable) %}

{% if var('union_schemas', none) %}

{% set relations = [] %}

{% for schema in var('union_schemas') %}

{% set relation=adapter.get_relation(

database=var(database_variable, default_database),

schema=schema,

identifier=table_identifier

) -%}

{% set relation_exists=relation is not none %}

{% if relation_exists %}

{% do relations.append(relation) %}

{% endif %}

{% endfor %}

{{ dbt_utils.union_relations(relations) }}

{% elif var('union_databases', none) %}

{% set relations = [] %}

{% for database in var('union_databases') %}

{% set relation=adapter.get_relation(

database=database,

schema=var(schema_variable, default_schema),

identifier=table_identifier

) -%}

{% set relation_exists=relation is not none %}

{% if relation_exists %}

{% do relations.append(relation) %}

{% endif %}

{% endfor %}

{{ dbt_utils.union_relations(relations) }}

{% else %}

select *

from {{ var(default_variable) }}

{% endif %}

{% endmacro %}