[#135] Support adding BinaryType Field

[shimizukawa]

• Support adding BinaryType field.
• Support forward migration with varchar to varbyte(size).
• Support backward migration from varbyte to varchar(size).
• Added BinaryType field to psycopg2 adapter.
• Testing with example/dj-sql-explorer.

[shimizukawa]

Now migration of example/dj-sql-explorer has been fixed.

forward migration

(venv) @shimizukawa ➜ /workspaces/django-redshift-backend/examples/dj-sql-explorer (135-binaryfield-support) $ python manage.py migrate explorer 0018
Operations to perform:
  Target specific migration: 0018_alter_databaseconnection_host_and_more, from explorer
Running migrations:
  Applying explorer.0018_alter_databaseconnection_host_and_more...ALTER TABLE "explorer_databaseconnection" ADD COLUMN "host_tmp" varbyte(255) DEFAULT %s NOT NULL; (params [<django_redshift_backend.psycopg2adapter.RedshiftBinary object at 0x7d87221efd30>])
UPDATE explorer_databaseconnection SET "host_tmp" = "host"::varbyte WHERE "host" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "host" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "host_tmp" TO "host"; (params [])
ALTER TABLE "explorer_databaseconnection" ADD COLUMN "password_tmp" varbyte(255) DEFAULT %s NOT NULL; (params [<django_redshift_backend.psycopg2adapter.RedshiftBinary object at 0x7d8721d2c810>])
UPDATE explorer_databaseconnection SET "password_tmp" = "password"::varbyte WHERE "password" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "password" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "password_tmp" TO "password"; (params [])
ALTER TABLE "explorer_databaseconnection" ADD COLUMN "user_tmp" varbyte(255) DEFAULT %s NOT NULL; (params [<django_redshift_backend.psycopg2adapter.RedshiftBinary object at 0x7d8721d2cc20>])
UPDATE explorer_databaseconnection SET "user_tmp" = "user"::varbyte WHERE "user" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "user" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "user_tmp" TO "user"; (params [])
 OK

backward migrattion

(venv) @shimizukawa ➜ /workspaces/django-redshift-backend/examples/dj-sql-explorer (135-binaryfield-support) $ python manage.py migrate explorer 0017
Operations to perform:
  Target specific migration: 0017_databaseconnection, from explorer
Running migrations:
  Rendering model states... DONE
  Unapplying explorer.0018_alter_databaseconnection_host_and_more...ALTER TABLE "explorer_databaseconnection" ADD COLUMN "user_tmp" varchar(255) DEFAULT %s NOT NULL; (params [''])
UPDATE explorer_databaseconnection SET "user_tmp" = "user"::varchar WHERE "user" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "user" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "user_tmp" TO "user"; (params [])
ALTER TABLE "explorer_databaseconnection" ADD COLUMN "password_tmp" varchar(255) DEFAULT %s NOT NULL; (params [''])
UPDATE explorer_databaseconnection SET "password_tmp" = "password"::varchar WHERE "password" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "password" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "password_tmp" TO "password"; (params [])
ALTER TABLE "explorer_databaseconnection" ADD COLUMN "host_tmp" varchar(255) DEFAULT %s NOT NULL; (params [''])
UPDATE explorer_databaseconnection SET "host_tmp" = "host"::varchar WHERE "host" IS NOT NULL; (params [])
ALTER TABLE explorer_databaseconnection DROP COLUMN "host" CASCADE; (params [])
ALTER TABLE explorer_databaseconnection RENAME COLUMN "host_tmp" TO "host"; (params [])
 OK

[shimizukawa]

dj-sql-explorer works fine.