From 67183dec787ddf42ebd20fccfacb5b98d756b3ed Mon Sep 17 00:00:00 2001
From: cbroz1 <chris.broz@ucsf.edu>
Date: Wed, 7 Feb 2024 08:29:14 -0800
Subject: [PATCH] #820

---
 src/spyglass/utils/dj_chains.py | 27 ++++++++++++++++++---------
 src/spyglass/utils/dj_mixin.py  | 13 +++++++------
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/spyglass/utils/dj_chains.py b/src/spyglass/utils/dj_chains.py
index d8152d020..275d859c3 100644
--- a/src/spyglass/utils/dj_chains.py
+++ b/src/spyglass/utils/dj_chains.py
@@ -135,12 +135,12 @@ def __init__(self, parent: Table, child: Table, connection=None):
             and MERGE_PK in child.heading.names
         ):
             logger.error("Child is a merge table. Use TableChains instead.")
+            return
 
         self._link_symbol = " -> "
         self.parent = parent
         self.child = child
         self._has_link = child.full_table_name in parent.descendants()
-        self._errors = []
 
     def __str__(self):
         """Return string representation of chain: parent -> child."""
@@ -221,17 +221,26 @@ def objects(self) -> List[dj.FreeTable]:
             else None
         )
 
-    def errors(self) -> List[str]:
-        """Return list of errors for each table in chain."""
-        return self._errors
-
-    def join(self, restricton: str = None) -> dj.expression.QueryExpression:
-        """Return join of tables in chain with restriction applied to parent."""
+    def join(
+        self, restricton: str = None, reverse_order: bool = False
+    ) -> dj.expression.QueryExpression:
+        """Return join of tables in chain with restriction applied to parent.
+
+        Parameters
+        ----------
+        restriction : str, optional
+            Restriction to apply to first table in the order.
+            Defaults to self.parent.restriction.
+        reverse_order : bool, optional
+            If True, join tables in reverse order. Defaults to False.
+        """
         if not self._has_link:
             return None
+
+        objects = self.objects[::-1] if reverse_order else self.objects
         restriction = restricton or self.parent.restriction or True
-        join = self.objects[0] & restriction
-        for table in self.objects[1:]:
+        join = objects[0] & restriction
+        for table in objects[1:]:
             try:
                 join = join.proj() * table
             except dj.DataJointError as e:
diff --git a/src/spyglass/utils/dj_mixin.py b/src/spyglass/utils/dj_mixin.py
index 7632e0249..bd6e0b244 100644
--- a/src/spyglass/utils/dj_mixin.py
+++ b/src/spyglass/utils/dj_mixin.py
@@ -61,10 +61,7 @@ def _nwb_table_tuple(self) -> tuple:
 
         Used to determine fetch_nwb behavior. Also used in Merge.fetch_nwb.
         Implemented as a cached_property to avoid circular imports."""
-        from spyglass.common.common_nwbfile import (
-            AnalysisNwbfile,
-            Nwbfile,
-        )  # noqa F401
+        from spyglass.common.common_nwbfile import AnalysisNwbfile, Nwbfile  # noqa F401
 
         table_dict = {
             AnalysisNwbfile: "analysis_file_abs_path",
@@ -74,7 +71,9 @@ def _nwb_table_tuple(self) -> tuple:
         resolved = getattr(self, "_nwb_table", None) or (
             AnalysisNwbfile
             if "-> AnalysisNwbfile" in self.definition
-            else Nwbfile if "-> Nwbfile" in self.definition else None
+            else Nwbfile
+            if "-> Nwbfile" in self.definition
+            else None
         )
 
         if not resolved:
@@ -278,7 +277,9 @@ def _get_exp_summary(self):
         empty_pk = {self._member_pk: "NULL"}
 
         format = dj.U(self._session_pk, self._member_pk)
-        sess_link = self._session_connection.join(self.restriction)
+        sess_link = self._session_connection.join(
+            self.restriction, reverse_order=True
+        )
 
         exp_missing = format & (sess_link - SesExp).proj(**empty_pk)
         exp_present = format & (sess_link * SesExp - exp_missing).proj()