fixing bug with multiple alter statements

Author: dantownsend

piccolo/query/methods/alter.py

@@ -60,7 +60,7 @@ class Add(AlterStatement):
     @property
     def querystring(self) -> QueryString:
         self.column._meta.name = self.name
-        return QueryString("ADD {}", self.column.querystring)
+        return QueryString("ADD COLUMN {}", self.column.querystring)
 
 
 @dataclasses.dataclass
@@ -218,8 +218,7 @@ def querystring(self) -> QueryString:
             )
         ]
 
-        for a in alterations:
-            query += " {}"
+        query += ",".join([" {}" for i in alterations])
 
         return QueryString(query, *alterations)
 

tests/table/test_alter.py

@@ -90,10 +90,28 @@ def test_unique(self):
         self.assertTrue(len(response), 2)
 
 
+class TestMultiple(DBTestCase):
+    """
+    Make sure multiple alter statements work correctly.
+    """
+
+    def test_multiple(self):
+        self.insert_row()
+
+        query = (
+            Manager.alter()
+            .add_column("column_a", Integer(default=0, null=True))
+            .add_column("column_b", Integer(default=0, null=True))
+        )
+        query.run_sync()
+
+        response = Band.raw("SELECT * FROM manager").run_sync()
+
+        column_names = response[0].keys()
+        self.assertTrue("column_a" in column_names)
+        self.assertTrue("column_b" in column_names)
+
+
 class TestNull(DBTestCase):
     def test_null(self):
         pass
-
-
-class TestMultiple(DBTestCase):
-    pass