diff --git a/code_thingies/dbtlearn/macros/no_nulls_in_columns.sql b/code_thingies/dbtlearn/macros/no_nulls_in_columns.sql
new file mode 100644
index 0000000..40af5d4
--- /dev/null
+++ b/code_thingies/dbtlearn/macros/no_nulls_in_columns.sql
@@ -0,0 +1,10 @@
+{% macro no_nulls_in_columns(model) %}
+    SELECT *
+    FROM
+        {{ model }}
+    WHERE
+        {% for col in adapter.get_columns_in_relation(model) -%}
+            {{col.column}} IS NULL OR
+        {% endfor %}
+        FALSE
+{% endmacro %}
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diff --git a/code_thingies/dbtlearn/tests/no_nulls_in_dim_listings.sql b/code_thingies/dbtlearn/tests/no_nulls_in_dim_listings.sql
new file mode 100644
index 0000000..e2a6fb5
--- /dev/null
+++ b/code_thingies/dbtlearn/tests/no_nulls_in_dim_listings.sql
@@ -0,0 +1 @@
+{{ no_nulls_in_columns(ref('dim_listings_cleansed')) }}
\ No newline at end of file
diff --git a/notes/8.md b/notes/8.md
index f96b728..bd7e45a 100644
--- a/notes/8.md
+++ b/notes/8.md
@@ -73,4 +73,11 @@ There are two kinds of tests:
 - Singular tests: you make any `SELECT` statement you want. If the `SELECT` statement is run and any data is found, the test is considered failed. If the statement is run and no rows are returned, the test is considered passed.
 - Built-in test: just a bunch of typical stuff: uniqueness, nullability, enum validations and relationship (referential integrity)
 
-You can also define your own custom generic tests.
\ No newline at end of file
+You can also define your own custom generic tests.
+
+
+## Macros
+
+- Macros are jinja templates.
+- There are many built-in macros in dbt, but you can also use your own macros.
+- dbt packages exist and you can use them to have more tests and macros that you can use.
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