diff --git a/d3b_api_client_cli/db/postgres/__init__.py b/d3b_api_client_cli/db/postgres/__init__.py
index 361171e..e24d185 100644
--- a/d3b_api_client_cli/db/postgres/__init__.py
+++ b/d3b_api_client_cli/db/postgres/__init__.py
@@ -25,9 +25,7 @@ class DBConnectionParam:
 
     def __post_init__(self):
         if any(
-            value is None
-            for value in vars(self).values()
-            if not callable(value)
+            not value for value in vars(self).values() if not callable(value)
         ):
             display = {}
             for k, v in vars(self).items():
diff --git a/tests/unit/db/test_postgres.py b/tests/unit/db/test_postgres.py
new file mode 100644
index 0000000..5671bd5
--- /dev/null
+++ b/tests/unit/db/test_postgres.py
@@ -0,0 +1,52 @@
+"""
+Unit tests for interacting with postgres
+"""
+
+import pytest
+
+from d3b_api_client_cli.db.postgres import DBConnectionParam
+
+
+def test_db_connection_params():
+    """
+    Test DBConnectionParam
+    """
+    username = "foo"
+    password = "bar"
+    hostname = "postgres.com"
+    port = "5432"
+    db_name = "postgres"
+
+    params = DBConnectionParam(
+        username=username,
+        password=password,
+        hostname=hostname,
+        port=port,
+        db_name=db_name,
+    )
+
+    assert params.username == username
+    assert params.password == password
+    assert params.hostname == hostname
+    assert params.port == port
+    assert params.db_name == db_name
+
+
+def test_db_connection_params_error():
+    """
+    Test DBConnectionParam errors
+    """
+    username = ""
+    password = ""
+    hostname = None
+    port = None
+    db_name = "postgres"
+
+    with pytest.raises(ValueError):
+        DBConnectionParam(
+            username=username,
+            password=password,
+            hostname=hostname,
+            port=port,
+            db_name=db_name,
+        )