From c04890112922afe243168e642cb729288d37660a Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Fri, 30 Dec 2022 05:58:16 +0000
Subject: [PATCH] allow `SelectRaw` with `Readable`

---
 piccolo/apps/playground/commands/run.py |  8 +++++++-
 piccolo/columns/readable.py             | 22 ++++++++++------------
 piccolo/table.py                        |  9 ++++++---
 3 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/piccolo/apps/playground/commands/run.py b/piccolo/apps/playground/commands/run.py
index 092b79c20..47fa9a1fb 100644
--- a/piccolo/apps/playground/commands/run.py
+++ b/piccolo/apps/playground/commands/run.py
@@ -23,6 +23,7 @@
 from piccolo.columns.readable import Readable
 from piccolo.engine import PostgresEngine, SQLiteEngine
 from piccolo.engine.base import Engine
+from piccolo.query import SelectRaw
 from piccolo.table import Table
 from piccolo.utils.warnings import colored_string
 
@@ -111,7 +112,12 @@ class DiscountCode(Table):
     def get_readable(cls) -> Readable:
         return Readable(
             template="%s - %s",
-            columns=[cls.code, cls.active],
+            columns=[
+                cls.code,
+                SelectRaw(
+                    "CASE WHEN active THEN 'active' ELSE 'inactive' END"
+                ),
+            ],
         )
 
 
diff --git a/piccolo/columns/readable.py b/piccolo/columns/readable.py
index 2748648d8..9d521d3b5 100644
--- a/piccolo/columns/readable.py
+++ b/piccolo/columns/readable.py
@@ -5,9 +5,6 @@
 
 from piccolo.columns.base import Selectable
 
-if t.TYPE_CHECKING:  # pragma: no cover
-    from piccolo.columns.base import Column
-
 
 @dataclass
 class Readable(Selectable):
@@ -18,32 +15,33 @@ class Readable(Selectable):
     """
 
     template: str
-    columns: t.Sequence[Column]
+    columns: t.Sequence[Selectable]
     output_name: str = "readable"
 
-    @property
-    def _columns_string(self) -> str:
+    def _get_columns_string(self, engine_type: str) -> str:
         return ", ".join(
-            i._meta.get_full_name(with_alias=False) for i in self.columns
+            i.get_select_string(engine_type=engine_type, with_alias=False)
+            for i in self.columns
         )
 
-    def _get_string(self, operator: str) -> str:
+    def _get_string(self, operator: str, engine_type: str) -> str:
+        columns_string = self._get_columns_string(engine_type=engine_type)
         return (
-            f"{operator}('{self.template}', {self._columns_string}) AS "
+            f"{operator}('{self.template}', {columns_string}) AS "
             f"{self.output_name}"
         )
 
     @property
     def sqlite_string(self) -> str:
-        return self._get_string(operator="PRINTF")
+        return self._get_string(operator="PRINTF", engine_type="sqlite")
 
     @property
     def postgres_string(self) -> str:
-        return self._get_string(operator="FORMAT")
+        return self._get_string(operator="FORMAT", engine_type="postgres")
 
     @property
     def cockroach_string(self) -> str:
-        return self._get_string(operator="FORMAT")
+        return self._get_string(operator="FORMAT", engine_type="cockroach")
 
     def get_select_string(self, engine_type: str, with_alias=True) -> str:
         try:
diff --git a/piccolo/table.py b/piccolo/table.py
index a6cdc64c4..961d0e9fc 100644
--- a/piccolo/table.py
+++ b/piccolo/table.py
@@ -713,9 +713,12 @@ def _get_related_readable(cls, column: ForeignKey) -> Readable:
 
         for readable_column in readable.columns:
             output_column = column
-            for fk in readable_column._meta.call_chain:
-                output_column = getattr(output_column, fk._meta.name)
-            output_column = getattr(output_column, readable_column._meta.name)
+            if isinstance(readable_column, Column):
+                for fk in readable_column._meta.call_chain:
+                    output_column = getattr(output_column, fk._meta.name)
+                output_column = getattr(
+                    output_column, readable_column._meta.name
+                )
             output_columns.append(output_column)
 
         output_name = f"{column._meta.name}_readable"