Populate group table

migrations/dimensions-config/1fae088c80b6.py

@@ -9,7 +9,7 @@
 import logging
 
 import sqlalchemy as sa
-from alembic import op
+from alembic import context, op
 
 # revision identifiers, used by Alembic.
 revision = "1fae088c80b6"
@@ -32,7 +32,12 @@ def downgrade() -> None:
 
 
 def _create_group_table() -> None:
-    op.create_table(
+    mig_context = context.get_context()
+    schema = mig_context.version_table_schema
+    bind = mig_context.bind
+    assert bind is not None
+
+    table = op.create_table(
         "group",
         sa.Column("instrument", sa.String(32), primary_key=True),
         sa.Column("name", sa.String(64), primary_key=True),
@@ -41,4 +46,23 @@ def _create_group_table() -> None:
             refcolumns=["instrument.name"],
             name="fkey_group_instrument_name_instrument",
         ),
+        schema=schema,
+    )
+
+    # Populate the new table based on the data in the exposure table.
+    metadata = sa.schema.MetaData(schema=schema)
+    exposure_table = sa.schema.Table("exposure", metadata, autoload_with=bind, schema=schema)
+    select = sa.select(
+        exposure_table.columns["instrument"],
+        exposure_table.columns["group_name"],
+    ).distinct()
+
+    op.execute(
+        table.insert().from_select(
+            [
+                "instrument",
+                "name",
+            ],
+            select,
+        )
     )