comparison app/models/.svn/text-base/query.rb.svn-base @ 245:051f544170fe

* Update to SVN trunk revision 4993

   # Helper method to generate the WHERE sql for a +field+, +operator+ and a +value+
   def sql_for_field(field, operator, value, db_table, db_field, is_custom_filter=false)
     sql = ''
     case operator
     when "="
-      sql = "#{db_table}.#{db_field} IN (" + value.collect{|val| "'#{connection.quote_string(val)}'"}.join(",") + ")"
+      if value.any?
+        sql = "#{db_table}.#{db_field} IN (" + value.collect{|val| "'#{connection.quote_string(val)}'"}.join(",") + ")"
+      else
+        # IN an empty set
+        sql = "1=0"
+      end
     when "!"
-      sql = "(#{db_table}.#{db_field} IS NULL OR #{db_table}.#{db_field} NOT IN (" + value.collect{|val| "'#{connection.quote_string(val)}'"}.join(",") + "))"
+      if value.any?
+        sql = "(#{db_table}.#{db_field} IS NULL OR #{db_table}.#{db_field} NOT IN (" + value.collect{|val| "'#{connection.quote_string(val)}'"}.join(",") + "))"
+      else
+        # NOT IN an empty set
+        sql = "1=1"
+      end
     when "!*"
       sql = "#{db_table}.#{db_field} IS NULL"
       sql << " OR #{db_table}.#{db_field} = ''" if is_custom_filter
     when "*"
       sql = "#{db_table}.#{db_field} IS NOT NULL"