From 5e0e787825e847eac1cc93375e26ea1d3f715d3e Mon Sep 17 00:00:00 2001
From: Stevan Earl <stevan.earl@asu.edu>
Date: Tue, 4 Aug 2026 12:55:18 -0700
Subject: [PATCH] fix: normalize blank biography maternal IDs (Problem #104)

---
 conversion/clean.sql | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/conversion/clean.sql b/conversion/clean.sql
index 8ed6acc..06c6c80 100644
--- a/conversion/clean.sql
+++ b/conversion/clean.sql
@@ -167,6 +167,12 @@ UPDATE biography
   SET b_birthgroup = NULLIF(BTRIM(b_birthgroup), '')
   WHERE b_birthgroup IS DISTINCT FROM NULLIF(BTRIM(b_birthgroup), '');
 
+-- Problem #104 BIOGRAPHY.B_MomID values stored as empty strings ('')
+-- rather than SQL NULL
+UPDATE biography
+  SET b_momid = NULLIF(BTRIM(b_momid), '')
+  WHERE b_momid IS DISTINCT FROM NULLIF(BTRIM(b_momid), '');
+
 
 --
 -- follow
-- 
2.34.1