1 files changed, 28 insertions, 15 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 0c7197a002..4046b3829d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -62,17 +62,17 @@ module ActiveRecord
     # notably, the instance methods provided by SchemaStatements are very useful.
     class AbstractAdapter
       ADAPTER_NAME = "Abstract".freeze
+      include ActiveSupport::Callbacks
+      define_callbacks :checkout, :checkin
+
       include Quoting, DatabaseStatements, SchemaStatements
       include DatabaseLimits
       include QueryCache
-      include ActiveSupport::Callbacks
       include ColumnDumper
       include Savepoints
 
       SIMPLE_INT = /\A\d+\z/
 
-      define_callbacks :checkout, :checkin
-
       attr_accessor :visitor, :pool
       attr_reader :schema_cache, :owner, :logger
       alias :in_use? :owner
@@ -106,7 +106,7 @@ module ActiveRecord
         @pool                = nil
         @schema_cache        = SchemaCache.new self
         @quoted_column_names, @quoted_table_names = {}, {}
-        @visitor             = arel_visitor
+        @visitor = arel_visitor
 
         if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
           @prepared_statements = true
@@ -161,6 +161,14 @@ module ActiveRecord
         SchemaCreation.new self
       end
 
+      # Returns an array of +Column+ objects for the table specified by +table_name+.
+      def columns(table_name) # :nodoc:
+        table_name = table_name.to_s
+        column_definitions(table_name).map do |field|
+          new_column_from_field(table_name, field)
+        end
+      end
+
       # this method must only be called while holding connection pool's mutex
       def lease
         if in_use?
@@ -491,9 +499,9 @@ module ActiveRecord
         result
       end
 
-      protected
+      private
 
-        def initialize_type_map(m) # :nodoc:
+        def initialize_type_map(m)
           register_class_with_limit m, %r(boolean)i,       Type::Boolean
           register_class_with_limit m, %r(char)i,          Type::String
           register_class_with_limit m, %r(binary)i,        Type::Binary
@@ -524,37 +532,37 @@ module ActiveRecord
           end
         end
 
-        def reload_type_map # :nodoc:
+        def reload_type_map
           type_map.clear
           initialize_type_map(type_map)
         end
 
-        def register_class_with_limit(mapping, key, klass) # :nodoc:
+        def register_class_with_limit(mapping, key, klass)
           mapping.register_type(key) do |*args|
             limit = extract_limit(args.last)
             klass.new(limit: limit)
           end
         end
 
-        def register_class_with_precision(mapping, key, klass) # :nodoc:
+        def register_class_with_precision(mapping, key, klass)
           mapping.register_type(key) do |*args|
             precision = extract_precision(args.last)
             klass.new(precision: precision)
           end
         end
 
-        def extract_scale(sql_type) # :nodoc:
+        def extract_scale(sql_type)
           case sql_type
           when /\((\d+)\)/ then 0
           when /\((\d+)(,(\d+))\)/ then $3.to_i
           end
         end
 
-        def extract_precision(sql_type) # :nodoc:
+        def extract_precision(sql_type)
           $1.to_i if sql_type =~ /\((\d+)(,\d+)?\)/
         end
 
-        def extract_limit(sql_type) # :nodoc:
+        def extract_limit(sql_type)
           case sql_type
           when /^bigint/i
             8
@@ -575,7 +583,7 @@ module ActiveRecord
           exception
         end
 
-        def log(sql, name = "SQL", binds = [], type_casted_binds = [], statement_name = nil)
+        def log(sql, name = "SQL", binds = [], type_casted_binds = [], statement_name = nil) # :doc:
           @instrumenter.instrument(
             "sql.active_record",
             sql:               sql,
@@ -590,14 +598,19 @@ module ActiveRecord
 
         def translate_exception(exception, message)
           # override in derived class
-          ActiveRecord::StatementInvalid.new(message)
+          case exception
+          when RuntimeError
+            exception
+          else
+            ActiveRecord::StatementInvalid.new(message)
+          end
         end
 
         def without_prepared_statement?(binds)
           !prepared_statements || binds.empty?
         end
 
-        def column_for(table_name, column_name) # :nodoc:
+        def column_for(table_name, column_name)
           column_name = column_name.to_s
           columns(table_name).detect { |c| c.name == column_name } ||
             raise(ActiveRecordError, "No such column: #{table_name}.#{column_name}")