fix: add unique constraint to tenant_default_models to prevent duplic… (#31221)

Co-authored-by: qiaofenglin <qiaofenglin@baidu.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Novice <novice12185727@gmail.com>

api/migrations/versions/2026_02_10_1507-f55813ffe2c8_fix_tenant_default_model_unique.py

@@ -0,0 +1,59 @@
+"""add unique constraint to tenant_default_models
+
+Revision ID: fix_tenant_default_model_unique
+Revises: 9d77545f524e
+Create Date: 2026-01-19 15:07:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+def _is_pg(conn):
+    return conn.dialect.name == "postgresql"
+
+
+# revision identifiers, used by Alembic.
+revision = 'f55813ffe2c8'
+down_revision = 'c3df22613c99'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # First, remove duplicate records keeping only the most recent one per (tenant_id, model_type)
+    # This is necessary before adding the unique constraint
+    conn = op.get_bind()
+    
+    # Delete duplicates: keep the record with the latest updated_at for each (tenant_id, model_type)
+    # If updated_at is the same, keep the one with the largest id as tiebreaker
+    if _is_pg(conn):
+        # PostgreSQL: Use DISTINCT ON for efficient deduplication
+        conn.execute(sa.text("""
+            DELETE FROM tenant_default_models
+            WHERE id NOT IN (
+                SELECT DISTINCT ON (tenant_id, model_type) id
+                FROM tenant_default_models
+                ORDER BY tenant_id, model_type, updated_at DESC, id DESC
+            )
+        """))
+    else:
+        # MySQL: Use self-join to find and delete duplicates
+        # Keep the record with latest updated_at (or largest id if updated_at is equal)
+        conn.execute(sa.text("""
+            DELETE t1 FROM tenant_default_models t1
+            INNER JOIN tenant_default_models t2
+            ON t1.tenant_id = t2.tenant_id 
+               AND t1.model_type = t2.model_type 
+               AND (t1.updated_at < t2.updated_at 
+                    OR (t1.updated_at = t2.updated_at AND t1.id < t2.id))
+        """))
+    
+    # Now add the unique constraint
+    with op.batch_alter_table('tenant_default_models', schema=None) as batch_op:
+        batch_op.create_unique_constraint('unique_tenant_default_model_type', ['tenant_id', 'model_type'])
+
+
+def downgrade():
+    with op.batch_alter_table('tenant_default_models', schema=None) as batch_op:
+        batch_op.drop_constraint('unique_tenant_default_model_type', type_='unique')

api/models/provider.py

@@ -181,6 +181,7 @@ class TenantDefaultModel(TypeBase):
     __table_args__ = (
         sa.PrimaryKeyConstraint("id", name="tenant_default_model_pkey"),
         sa.Index("tenant_default_model_tenant_id_provider_type_idx", "tenant_id", "provider_name", "model_type"),
+        sa.UniqueConstraint("tenant_id", "model_type", name="unique_tenant_default_model_type"),
     )
 
     id: Mapped[str] = mapped_column(