storing column params, so table representation can be recreated for migrations and playground

Author: dantownsend

docs/src/piccolo/migrations/create.rst

@@ -144,9 +144,3 @@ Piccolo needs to be able to import these files using ``importlib``, so make
 sure the paths are correct.
 
 Piccolo will then add the table definitions the migration.
-
-To create all tables in a particular file, you can use a placeholder:
-
-.. code-block:: bash
-
-    piccolo new -c ..tables.*

piccolo/columns/base.py

@@ -39,6 +39,8 @@ class ColumnMeta:
     key: bool = False
     unique: bool = False
 
+    params: t.Dict[str, t.Any] = field(default_factory=dict)
+
     # Set by the Table Metaclass:
     _name: t.Optional[str] = None
     _table: t.Optional[Table] = None
@@ -105,9 +107,15 @@ def __init__(
         primary: bool = False,
         key: bool = False,
         unique: bool = False,
+        **kwargs,
     ) -> None:
+        # Used for migrations:
+        kwargs.update(
+            {"null": null, "primary": primary, "key": key, "unique": unique}
+        )
+
         self._meta = ColumnMeta(
-            null=null, primary=primary, key=key, unique=unique
+            null=null, primary=primary, key=key, unique=unique, params=kwargs
         )
 
     def is_in(self, values: Iterable) -> Where:

piccolo/columns/column_types.py

@@ -21,12 +21,21 @@ def __init__(
     ) -> None:
         self.length = length
         self.default = default
+        kwargs.update({"length": length, "default": default})
         super().__init__(**kwargs)
 
+    @property
+    def column_type(self):
+        if self.length:
+            return f"VARCHAR({self.length})"
+        else:
+            return "VARCHAR"
+
 
 class Integer(Column):
     def __init__(self, default: int = None, **kwargs) -> None:
         self.default = default
+        kwargs.update({"default": default})
         super().__init__(**kwargs)
 
 
@@ -68,6 +77,7 @@ class Timestamp(Column):
 
     def __init__(self, default: "Datetime" = None, **kwargs) -> None:
         self.default = default
+        kwargs.update({"default": default})
         super().__init__(**kwargs)
 
 
@@ -77,6 +87,7 @@ class Boolean(Column):
 
     def __init__(self, default: bool = False, **kwargs) -> None:
         self.default = default
+        kwargs.update({"default": default})
         super().__init__(**kwargs)
 
 
@@ -118,6 +129,7 @@ class ForeignKey(Integer):
     column_type = "INTEGER"
 
     def __init__(self, references: t.Type[Table], **kwargs) -> None:
+        kwargs.update({"references": references})
         super().__init__(**kwargs)
         self._foreign_key_meta = ForeignKeyMeta(references=references)
 

piccolo/table.py

@@ -45,7 +45,7 @@ def __str__(cls):
         """
         Returns a basic string representation of the table and its columns.
 
-        Used by the playground.
+        Used by the playground, and migrations.
         """
         spacer = "\n    "
         columns = []