X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FQ-Branch.git;a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FReference.pm;h=1f9dd330861fb7cde46f0d0906fa8e2bf3bb6948;hp=6075f4c1e45635ef521186e913cfd46b2a7263ef;hb=0f4493cb09db57441423bebf0a4df40b0a3ebfd4;hpb=24479414b207dfb118a9704920191324e5da2a32

diff --git a/lib/SQL/Abstract/Reference.pm b/lib/SQL/Abstract/Reference.pm
index 6075f4c..1f9dd33 100644
--- a/lib/SQL/Abstract/Reference.pm
+++ b/lib/SQL/Abstract/Reference.pm
@@ -279,6 +279,19 @@ an expander has been registered for that node type:
   id OP ?
   [ 'value' ]
 
+If the value is undef, attempts to convert equality and like ops to IS NULL,
+and inequality and not like to IS NOT NULL:
+
+  # expr
+  { id => { '!=' => undef } }
+
+  # aqt
+  { -op => [ 'is_not_null', { -ident => [ 'id' ] } ] }
+
+  # query
+  id IS NOT NULL
+  []
+
 =head3 identifier hashpair w/simple value
 
 Equivalent to a hashtriple with an op of '='.