7914 Using a better way to get the defaults from db.

Changes:

* According to postgreSQL documentation:
(http://www.postgresql.org/docs/8.2/static/catalog-pg-attrdef.html)
we should not be using 'adsrc' field because this field is unaware of
outside changes that could affect the way that default values are
represented. Thus, I changed the queries to use
"pg_get_expr(adbin, adrelid)" instead of the historical "adsrc" field.

* Remove parsing of character type default values for 8.1 formatting since
Rails doesn't support postgreSQL 8.1 anymore.

* Remove misleading comment unrelated to code.

1 files changed, 7 insertions, 12 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index e34acd8dae..80a0c6d13c 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -147,9 +147,6 @@ module ActiveRecord
             # Character types
             when /\A\(?'(.*)'::.*\b(?:character varying|bpchar|text)\z/m
               $1
-            # Character types (8.1 formatting)
-            when /\AE'(.*)'::(?:character varying|bpchar|text)\z/m
-              $1.gsub(/\\(\d\d\d)/) { $1.oct.chr }
             # Binary data types
             when /\A'(.*)'::bytea\z/m
               $1
@@ -965,16 +962,13 @@ module ActiveRecord
         end_sql
 
         if result.nil? or result.empty?
-          # If that fails, try parsing the primary key's default value.
-          # Support the 7.x and 8.0 nextval('foo'::text) as well as
-          # the 8.1+ nextval('foo'::regclass).
           result = query(<<-end_sql, 'SCHEMA')[0]
             SELECT attr.attname,
               CASE
-                WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
-                  substr(split_part(def.adsrc, '''', 2),
-                         strpos(split_part(def.adsrc, '''', 2), '.')+1)
-                ELSE split_part(def.adsrc, '''', 2)
+                WHEN split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2) ~ '.' THEN
+                  substr(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2),
+                         strpos(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2), '.')+1)
+                ELSE split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2)
               END
             FROM pg_class       t
             JOIN pg_attribute   attr ON (t.oid = attrelid)
@@ -982,7 +976,7 @@ module ActiveRecord
             JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])
             WHERE t.oid = '#{quote_table_name(table)}'::regclass
               AND cons.contype = 'p'
-              AND def.adsrc ~* 'nextval'
+              AND pg_get_expr(def.adbin, def.adrelid) ~* 'nextval'
           end_sql
         end
 
@@ -1282,7 +1276,8 @@ module ActiveRecord
         #  - ::regclass is a function that gives the id for a table name
         def column_definitions(table_name) #:nodoc:
           exec_query(<<-end_sql, 'SCHEMA').rows
-            SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
+            SELECT a.attname, format_type(a.atttypid, a.atttypmod),
+                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
               FROM pg_attribute a LEFT JOIN pg_attrdef d
                 ON a.attrelid = d.adrelid AND a.attnum = d.adnum
              WHERE a.attrelid = '#{quote_table_name(table_name)}'::regclass