Merge pull request #220 from fishtown-analytics/feature/get_relations_by_schema_prefix

feature/get relations by schema prefix

Author: JDW818

README.md

@@ -468,6 +468,35 @@ handy paired with `union_relations`.
 * `database` (optional, default = `target.database`): The database to inspect
 for relations.
 
+#### get_relations_by_pattern
+> This was built from the get_relations_by_prefix macro.
+
+Returns a list of [Relations](https://docs.getdbt.com/docs/writing-code-in-dbt/class-reference/#relation)
+that match a given schema or table pattern and table/view name with an optional exclusion pattern. Like its cousin
+get_relations_by_prefix, it's particularly handy paired with `union_relations`.
+**Usage:**
+```
+-- Returns a list of relations that match schema%.table
+{% set relations = dbt_utils.get_relations_by_pattern('schema_pattern%', 'table_pattern') %}
+
+-- Returns a list of relations that match schema.table%
+{% set relations = dbt_utils.get_relations_by_pattern('schema_pattern', 'table_pattern%') %}
+
+-- Returns a list of relations as above, excluding any that end in `deprecated`
+{% set relations = dbt_utils.get_relations_by_pattern('schema_pattern', 'table_pattern%', '%deprecated') %}
+
+-- Example using the union_relations macro
+{% set event_relations = dbt_utils.get_relations_by_pattern('venue%', 'clicks') %}
+{{ dbt_utils.union_relations(relations = event_relations) }}
+```
+
+**Args:**
+* `schema_pattern` (required): The schema pattern to inspect for relations.
+* `table_pattern` (required): The name of the table/view (case insensitive).
+* `exclude` (optional): Exclude any relations that match this table pattern.
+* `database` (optional, default = `target.database`): The database to inspect
+for relations.
+
 #### group_by ([source](macros/sql/groupby.sql))
 This macro build a group by statement for fields 1...N
 

integration_tests/models/sql/test_get_relations_by_pattern.sql

@@ -0,0 +1,4 @@
+{{ config(materialized = 'table') }}
+
+{% set relations = dbt_utils.get_relations_by_pattern(target.schema, 'data_events_') %}
+{{ dbt_utils.union_relations(relations) }}

macros/sql/get_relations_by_pattern.sql

@@ -0,0 +1,23 @@
+{% macro get_relations_by_pattern(schema_pattern, table_pattern, exclude='', database=target.database) %}
+
+    {%- call statement('get_tables', fetch_result=True) %}
+
+      {{ dbt_utils.get_tables_by_pattern(schema_pattern, table_pattern, exclude, database) }}
+
+    {%- endcall -%}
+
+    {%- set table_list = load_result('get_tables') -%}
+
+    {%- if table_list and table_list['table'] -%}
+        {%- set tbl_relations = [] -%}
+        {%- for row in table_list['table'] -%}
+            {%- set tbl_relation = api.Relation.create(database, row.table_schema, row.table_name) -%}
+            {%- do tbl_relations.append(tbl_relation) -%}
+        {%- endfor -%}
+
+        {{ return(tbl_relations) }}
+    {%- else -%}
+        {{ return([]) }}
+    {%- endif -%}
+
+{% endmacro %}

macros/sql/get_tables_by_pattern.sql

@@ -0,0 +1,12 @@
+{% macro get_tables_by_pattern(schema_pattern, table_pattern, exclude='', database=target.database) %}
+
+        select distinct 
+            table_schema as "table_schema", table_name as "table_name"
+        from {{database}}.information_schema.tables
+        where table_schema ilike '{{ schema_pattern }}'
+        and table_name ilike '{{ table_pattern }}'
+        and table_name not ilike '{{ exclude }}'
+
+{% endmacro %} 
+
+