Dimension Hierarchies (#1564)

* Add support for dimensional hierarchies

* Add history tracking for hierarchies and audit info like created by and owner

* Move database functions to classmethods

* Add tests for hierarchies

* Add hierarchies database migration

* Remove the hard-coded level order inputs when creating hierarchies since they can be derived from the list order

* Remove validate endpoint for hierarchies

Author: shangyian

datajunction-server/datajunction_server/alembic/versions/2025_11_22_2254-95732205ad12_add_hierarchies_tables.py

@@ -0,0 +1,74 @@
+"""Add hierarchies tables
+
+Revision ID: 95732205ad12
+Revises: be76e22dd71a
+Create Date: 2025-11-22 22:54:00.000000+00:00
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "95732205ad12"
+down_revision = "be76e22dd71a"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create hierarchies table
+    op.create_table(
+        "hierarchies",
+        sa.Column(
+            "id",
+            sa.BigInteger().with_variant(sa.Integer(), "sqlite"),
+            nullable=False,
+        ),
+        sa.Column("name", sa.String(), nullable=False),
+        sa.Column("display_name", sa.String(), nullable=True),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("created_by_id", sa.Integer(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["created_by_id"],
+            ["users.id"],
+            name="fk_hierarchies_created_by_id_users",
+        ),
+        sa.PrimaryKeyConstraint("id", name="pk_hierarchies"),
+        sa.UniqueConstraint("name", name="uq_hierarchies_name"),
+    )
+
+    # Create hierarchy_levels table
+    op.create_table(
+        "hierarchy_levels",
+        sa.Column("id", sa.BigInteger(), nullable=False),
+        sa.Column("hierarchy_id", sa.BigInteger(), nullable=False),
+        sa.Column("name", sa.String(), nullable=False),
+        sa.Column("dimension_node_id", sa.BigInteger(), nullable=False),
+        sa.Column("level_order", sa.Integer(), nullable=False),
+        sa.Column("grain_columns", sa.JSON(), nullable=True),
+        sa.ForeignKeyConstraint(
+            ["hierarchy_id"],
+            ["hierarchies.id"],
+            name="fk_hierarchy_levels_hierarchy_id_hierarchies",
+        ),
+        sa.ForeignKeyConstraint(
+            ["dimension_node_id"],
+            ["node.id"],
+            name="fk_hierarchy_levels_dimension_node_id_node",
+        ),
+        sa.PrimaryKeyConstraint("id", name="pk_hierarchy_levels"),
+        sa.UniqueConstraint(
+            "hierarchy_id",
+            "name",
+            name="hierarchy_levels_hierarchy_id_name_key",
+        ),
+    )
+
+
+def downgrade():
+    # Drop hierarchy_levels first (has foreign key to hierarchies)
+    op.drop_table("hierarchy_levels")
+
+    # Drop hierarchies table
+    op.drop_table("hierarchies")