X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?p=ypp-sc-tools.db-test.git;a=blobdiff_plain;f=yarrg%2Fdevel-notes;h=f4f6066788c045383e68aac313b237c156e65d85;hp=fef5adc8bdb748477cb5f0418734f2fb245affea;hb=3ca67ce14212ba4421029d7b8db90f03f106c67c;hpb=0191640f64abf2adf416dbd2fcc6632ff58e8e8f

diff --git a/yarrg/devel-notes b/yarrg/devel-notes
index fef5adc..f4f6066 100644
--- a/yarrg/devel-notes
+++ b/yarrg/devel-notes
@@ -1,9 +1,28 @@
+
+removing an obsolete commodity:
+
+  select * from (select * from sell union select * from buy) left outer join commods using (commodid) where commods.commodname = 'Black dye' limit 10;
+
+if that produces no output then:
+
+  begin;
+  delete from commods where commodname like 'Black dye';
+  select * from (select * from sell union select * from buy) left outer join commods using (commodid) where commods.commodname is null limit 10;
+
+and if that produces no output then:
+  commit;
+otherwise
+  rollback;
+
+=======================================
+
 ceb's example route:
   alpha,byrne,papaya,turtle,jorvik,luthien
 
 example mixed arbitrage/trade
   xi,heph
 
+========================================
 
 To remedy bug fixed in 01c14767c024ac56686dbbfcd88d9f3a0b4b1574,
 did this: