Make parent not null, add commit index (#35)

conbench/entities/commit.py

@@ -15,7 +15,7 @@ class Commit(Base, EntityMixin):
     __tablename__ = "commit"
     id = NotNull(s.String(50), primary_key=True, default=generate_uuid)
     sha = NotNull(s.String(50))
-    parent = Nullable(s.String(50))
+    parent = NotNull(s.String(50))
     repository = NotNull(s.String(100))
     message = NotNull(s.String(250))
     author_name = NotNull(s.String(100))
@@ -24,6 +24,13 @@ class Commit(Base, EntityMixin):
     timestamp = NotNull(s.DateTime(timezone=False))
 
 
+s.Index(
+    "commit_index",
+    Commit.sha,
+    unique=True,
+)
+
+
 class _Serializer(EntitySerializer):
     def _dump(self, commit):
         return {

migrations/versions/b86538f84533_commit_sha_index.py

@@ -0,0 +1,23 @@
+"""commit sha index
+
+Revision ID: b86538f84533
+Revises: bb5acca23f97
+Create Date: 2021-04-21 13:35:38.613978
+
+"""
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = "b86538f84533"
+down_revision = "bb5acca23f97"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_index("commit_index", "commit", ["sha"], unique=True)
+
+
+def downgrade():
+    op.drop_index("commit_index", table_name="commit")

migrations/versions/bb5acca23f97_parent_not_null.py

@@ -0,0 +1,28 @@
+"""parent not null
+
+Revision ID: bb5acca23f97
+Revises: 662175f2e6c6
+Create Date: 2021-04-21 11:11:00.621174
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "bb5acca23f97"
+down_revision = "662175f2e6c6"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.alter_column(
+        "commit", "parent", existing_type=sa.VARCHAR(length=50), nullable=False
+    )
+
+
+def downgrade():
+    op.alter_column(
+        "commit", "parent", existing_type=sa.VARCHAR(length=50), nullable=True
+    )