diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md index 08547f0406..6e20d61ef5 100644 --- a/CONTRIBUTING.md +++ b/CONTRIBUTING.md @@ -505,3 +505,21 @@ https://github.com/apache/incubator-superset/pull/3013 with a PGP key and providing MD5, Apache voting, as well as publishing to Apache's SVN repository. View the ASF docs for more information. + + +## Merging DB migrations + +When 2 db migrations collide, you'll get an error message like this one: + +``` + alembic.util.exc.CommandError: Multiple head revisions are present for + given argument 'head'; please specify a specific target + revision, '@head' to narrow to a specific head, + or 'heads' for all heads` +``` + +To fix it, first run `superset db heads`, this should list 2 or more +migration hashes. Then run +`superset db merge {PASTE_SHA1_HERE} {PASTE_SHA2_HERE}`. This will create +a new merge migration. You can then `superset db upgrade` to this new +checkpoint. diff --git a/superset/migrations/versions/705732c70154_.py b/superset/migrations/versions/705732c70154_.py new file mode 100644 index 0000000000..212f69a854 --- /dev/null +++ b/superset/migrations/versions/705732c70154_.py @@ -0,0 +1,22 @@ +"""empty message + +Revision ID: 705732c70154 +Revises: ('4451805bbaa1', '1d9e835a84f9') +Create Date: 2018-07-22 21:51:19.235558 + +""" + +# revision identifiers, used by Alembic. +revision = '705732c70154' +down_revision = ('4451805bbaa1', '1d9e835a84f9') + +from alembic import op +import sqlalchemy as sa + + +def upgrade(): + pass + + +def downgrade(): + pass