fix: use default null for from_address in migration

Author: amandazhuyilan

migrations/versions/c563e06b01b3_add_sender_email_in_emailnotification.py

@@ -21,7 +21,23 @@
 
 def upgrade() -> None:
     # ### commands auto generated by Alembic - please adjust! ###
-    op.add_column('emailnotification', sa.Column('from_address', sqlmodel.sql.sqltypes.AutoString(), nullable=False))
+    op.add_column(
+        "emailnotification",
+        sa.Column(
+            "from_address",
+            sqlmodel.sql.sqltypes.AutoString(),
+            nullable=True,
+            server_default="",
+        ),
+    )
+    op.execute(sa.text("UPDATE emailnotification SET from_address = '' WHERE from_address IS NULL"))
+    op.alter_column(
+        "emailnotification",
+        "from_address",
+        existing_type=sqlmodel.sql.sqltypes.AutoString(),
+        nullable=False,
+        server_default=None,
+    )
     op.create_index(op.f('ix_emailnotification_from_address'), 'emailnotification', ['from_address'], unique=False)
     # ### end Alembic commands ###