Added a OCI8-based Oracle adapter that has been verified to work with Oracle 8 and 9 #629 [Graham Jenkins]. Removed Maiks Oracle adapter until it can be merged with the OCI one.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@761 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 259 insertions, 244 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/oci_adapter.rb b/activerecord/lib/active_record/connection_adapters/oci_adapter.rb
new file mode 100644
index 0000000000..eb966fa9bb
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/oci_adapter.rb
@@ -0,0 +1,259 @@
+# This is an Oracle adapter for the ActiveRecord persistence framework. It relies upon the OCI8
+# driver, which works with Oracle 8i and above. It was developed on Windows 2000
+# against an 8i database, using ActiveRecord 1.6.0 and OCI8 0.1.9. It has also been tested against
+# a 9i database.
+#
+# Implementation notes:
+# 1.  I had to redefine a method in ActiveRecord to make it possible to implement an autonumbering
+#     solution for oracle. It's implemented in a way that is intended to not break other adapters.
+# 2.  Default value support needs a patch to the OCI8 driver, to enable it to read LONG columns.
+#     LONG is deprecated, and so may never be properly added to driver.
+#     A similar patch is needed for TIMESTAMP.
+#     This is dangerous because it may break with newer versions of the driver.
+# 3.  Large Object support works by an after_save callback added to the ActiveRecord. This is not
+#     a problem - you can add other (chained) after_save callbacks.
+# 4.  LIMIT and OFFSET work by scrolling through a cursor - no rownum select from select required.
+#     It does mean that large OFFSETs will have to scroll through the intervening records. To keep
+#     consistency with other adapters I've allowed the LIMIT and OFFSET clauses to be included in
+#     the sql string and later extracted them by parsing the string.
+#
+# Usage notes:
+# 1.  Key generation uses a sequence "rails_sequence" for all tables. (I couldn't find a simple
+#     and safe way of passing table-specific sequence information to the adapter.)
+# 2.  Oracle uses DATE or TIMESTAMP datatypes for both dates and times. Consequently I have had to
+#     resort to some hacks to get data converted to Date or Time in Ruby.
+#     If the column_name ends in _time it's created as a Ruby Time. Else if the
+#     hours/minutes/seconds are 0, I make it a Ruby Date. Else it's a Ruby Time.
+#     This is nasty - but if you use Duck Typing you'll probably not care very much.
+#     In 9i it's tempting to map DATE to Date and TIMESTAMP to Time but I don't think that is
+#     valid - too many databases use DATE for both.
+#     Timezones and sub-second precision on timestamps are not supported.
+# 3.  Default values that are functions (such as "SYSDATE") are not supported. This is a
+#     restriction of the way active record supports default values.
+# 4.  Referential integrity constraints are not fully supported. Under at least
+#     some circumstances, active record appears to delete parent and child records out of
+#     sequence and out of transaction scope. (Or this may just be a problem of test setup.)
+#
+# Do what you want with this code, at your own peril, but if any significant portion of my code
+# remains then please acknowledge my contribution.
+# Copyright 2005 Graham Jenkins
+# $Revision: 1.2 $
+require 'active_record/connection_adapters/abstract_adapter'
+
+begin
+  require_library_or_gem 'oci8' unless self.class.const_defined? :OCI8
+
+  module ActiveRecord
+    module ConnectionAdapters
+      class OCIColumn < Column
+        attr_reader :sql_type
+
+        def initialize(name, default, limit, sql_type, scale)
+          @name, @limit, @sql_type, @scale, @sequence = name, limit, sql_type, scale
+          @type = simplified_type sql_type
+          @default = type_cast default
+        end
+
+        def simplified_type(field_type)
+          case field_type
+          when /char/i                          : :string
+          when /num|float|double|dec|real|int/i : @scale == 0 ? :integer : :float
+          when /date|time/i                     : @name =~ /_at$/ ? :time : :datetime
+          when /lob/i                           : :binary
+          end
+        end
+
+        def type_cast(value)
+          return nil if value.nil? || value =~ /^\s*null\s*$/i
+          case type
+          when :string   then value
+          when :integer  then value.to_i
+          when :float    then value.to_f
+          when :datetime then cast_to_date_or_time(value)
+          when :time     then cast_to_time(value)
+          else value
+          end
+        end
+
+        def cast_to_date_or_time(value)
+          return value if value.is_a? Date
+          guess_date_or_time (value.is_a? Time) ?
+            value : Time.local(*value.split(/\D+/).map{ |x| x.to_i })
+        end
+
+        def cast_to_time(value)
+          return value if value.is_a? Time
+          Time.local(2000, 1, 1,*value.split(/\D+/).map{ |x| x.to_i })
+        end
+
+        def guess_date_or_time(value)
+          (value.hour == 0 and value.min == 0 and value.sec == 0) ?
+            Date.new(value.year, value.month, value.day) : value
+        end
+      end
+
+      class OCIAdapter < AbstractAdapter
+        def quote_string(s)
+          s.gsub /'/, "''"
+        end
+
+        def quote(value, column = nil)
+          if column and column.type == :binary then %Q{empty_#{ column.sql_type }()}
+          else case value
+            when String     then %Q{'#{quote_string(value)}'}
+            when NilClass     then 'null'
+            when TrueClass    then '1'
+            when FalseClass   then '0'
+            when Numeric    then value.to_s
+            when Date, Time   then %Q{'#{value.strftime("%Y-%m-%d %H:%M:%S")}'}
+            else           %Q{'#{quote_string(value.to_yaml)}'}
+            end
+          end
+        end
+
+        def select_all(sql, name = nil)
+          offset = sql =~ /OFFSET (\d+)$/ ? $1.to_i : -1
+          sql, limit = $1, $2.to_i if sql =~ /(.*)(?: LIMIT[= ](\d+))(\s*OFFSET \d+)?$/
+          cursor = log(sql, name, @connection) { @connection.exec sql }
+          cols = cursor.get_col_names.map { |x| x.downcase }
+          rows = []
+          while row = cursor.fetch
+            next if cursor.row_count <= offset
+            hash = Hash.new
+            cols.each_with_index { |col, i|
+              hash[col] = case row[i]
+                when OCI8::LOB
+                  name == 'Writable Large Object' ? row[i]: row[i].read
+                when OraDate
+                  (row[i].hour == 0 and row[i].minute == 0 and row[i].second == 0) ?
+                    row[i].to_date : row[i].to_time
+                else row[i]
+                end
+            }
+            rows << hash
+            break if rows.size == limit
+          end
+          rows
+        ensure
+          cursor.close if cursor
+        end
+
+        def select_one(sql, name = nil)
+          result = select_all sql, name
+          result.size > 0 ? result.first : nil
+        end
+
+        def columns(table_name, name = nil)
+          cols = select_all(%Q{
+              select column_name, data_type, data_default, data_length, data_scale
+              from user_tab_columns where table_name = '#{table_name.upcase}'}
+          ).map { |row|
+            OCIColumn.new row['column_name'].downcase, row['data_default'],
+              row['data_length'], row['data_type'], row['data_scale']
+          }
+          cols
+        end
+
+        def insert(sql, name = nil, pk = nil, id_value = nil)
+          if pk.nil? # Who called us? What does the sql look like? No idea!
+            execute sql, name
+          elsif id_value # Pre-assigned id
+            log(sql, name, @connection) { @connection.exec sql }
+          else # Assume the sql contains a bind-variable for the id
+            id_value = select_one("select rails_sequence.nextval id from dual")['id']
+            log(sql, name, @connection) { @connection.exec sql, id_value }
+          end
+          id_value
+        end
+
+        def execute(sql, name = nil)
+          log(sql, name, @connection) { @connection.exec sql }
+        end
+
+        alias :update :execute
+        alias :delete :execute
+
+        def add_limit!(sql, limit)
+          sql << "LIMIT=" << limit.to_s
+        end
+
+        def begin_db_transaction()
+          @connection.autocommit = false
+        end
+
+        def commit_db_transaction()
+          @connection.commit
+        ensure
+          @connection.autocommit = true
+        end
+
+        def rollback_db_transaction()
+          @connection.rollback
+        ensure
+          @connection.autocommit = true
+        end
+
+        def adapter_name()
+          'OCI'
+        end
+      end
+    end
+  end
+
+  module ActiveRecord
+    class Base
+      def self.oci_connection(config)
+        conn = OCI8.new config[:username], config[:password], config[:host]
+        conn.exec %q{alter session set nls_date_format = 'YYYY-MM-DD HH24:MI:SS'}
+        conn.exec %q{alter session set nls_timestamp_format = 'YYYY-MM-DD HH24:MI:SS'}
+        conn.autocommit = true
+        ConnectionAdapters::OCIAdapter.new conn, logger
+      end
+
+      alias :attributes_with_quotes_pre_oci :attributes_with_quotes
+      # Enable the id column to be bound into the sql later, by the adapter's insert method.
+      # This is preferable to inserting the hard-coded value here, because the insert method
+      # needs to know the id value explicitly.
+      def attributes_with_quotes(creating = true)
+        aq = attributes_with_quotes_pre_oci creating
+        if connection.class == ConnectionAdapters::OCIAdapter
+          aq[self.class.primary_key] = ":id" if creating && aq[self.class.primary_key].nil?
+        end
+        aq
+      end
+
+      after_save :write_lobs
+
+      # After setting large objects to empty, select the OCI8::LOB and write back the data
+      def write_lobs()
+        if connection.class == ConnectionAdapters::OCIAdapter
+          self.class.columns.select { |c| c.type == :binary }.each { |c|
+            break unless value = self[c.name]
+            lob = connection.select_one(
+              "select #{ c.name} from #{ self.class.table_name } WHERE #{ self.class.primary_key} = #{quote(id)}",
+              'Writable Large Object'
+              )[c.name]
+            lob.write value
+          }
+        end
+      end
+
+      private :write_lobs
+    end
+  end
+
+  class OCI8
+    class Cursor
+      alias :define_a_column_pre_ar :define_a_column
+      def define_a_column(i)
+        case do_ocicall(@ctx) { @parms[i - 1].attrGet(OCI_ATTR_DATA_TYPE) }
+        when 8    : @stmt.defineByPos(i, String, 65535) # Read LONG values
+        when 187  : @stmt.defineByPos(i, OraDate) # Read TIMESTAMP values
+        else define_a_column_pre_ar i
+        end
+    	end
+    end
+  end
+rescue LoadError
+  # OCI8 driver is unavailable.
+end
\ No newline at end of file
diff --git a/activerecord/lib/active_record/connection_adapters/oracle_adapter.rb b/activerecord/lib/active_record/connection_adapters/oracle_adapter.rb
deleted file mode 100644
index 2cdb7ec3f7..0000000000
--- a/activerecord/lib/active_record/connection_adapters/oracle_adapter.rb
+++ /dev/null
@@ -1,244 +0,0 @@
-# Author: Maik Schmidt <contact@maik-schmidt.de>
-require 'active_record/connection_adapters/abstract_adapter'
-require 'date'
-
-begin
-
-  module ActiveRecord
-    class Base
-      # Establishes a connection to the database that's used by
-      # all Active Record objects
-      def self.oracle_connection(config) # :nodoc:
-        require 'oracle' unless self.class.const_defined?(:ORAconn)
-        symbolize_strings_in_hash(config)
-        usr = config[:username] || ''
-        pwd = config[:password] || ''
-        db = config[:database] || ''
-
-        connection = ORAconn.logon(usr, pwd, db)
-        cursor = connection.open
-        cursor.parse("ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD'")
-        rows_affected = cursor.exec
-        cursor.close
-        ConnectionAdapters::OracleAdapter.new(connection)
-      end
-    end
-
-    module ConnectionAdapters
-      class OracleAdapter < AbstractAdapter
-        def select_all(sql, name = nil)
-          select(sql, name)
-        end
-
-        def select_one(sql, name = nil)
-          select(sql, name).first
-        end
-
-        # Oracle does not support auto-generated columns, so we have to use
-        # sequences. Every insert is followed by a select statement, which
-        # returns the current sequence value. The statements are encapsulated
-        # in an anonymous PL/SQL block (supported since Oracle 7.3) to prevent
-        # race conditions and to maximize performance.
-        def insert(sql, name = nil, pk = nil, id_value = nil)
-          new_id = nil
-          if !id_value.nil?
-            execute(sql, name)
-            new_id = id_value
-          else
-            pk_col = pk || ActiveRecord::Base::primary_key
-            if sql !~ Regexp.new('\b' + pk_col + '\b')
-              seq_name = sql.sub(/^\s*insert\s+?into\s+(\S+).*$/im, '\1') + "_id"
-              sql.sub!(/(into\s+.*?\()/im, '\1' + "#{pk_col}, ")
-              sql.sub!(/(values\s*\()/im, '\1' + "#{seq_name}.nextval, ")
-              new_id = ' ' * 40 # Enough space for String representation of ID?
-              log(sql, name, @connection) do |connection| 
-                cursor = connection.open
-                s = "begin #{sql}; select #{seq_name}.currval into :new_id from dual; end;"
-                cursor.parse(s)
-                cursor.bindrv(':new_id', new_id)
-                cursor.exec
-                cursor.close
-                new_id = new_id.to_i
-              end
-            else
-              execute(sql, name)
-            end
-          end
-          new_id
-        end
-
-        def execute(sql, name = nil)
-          rows_affected = 0
-          log(sql, name, @connection) do |connection| 
-            cursor = connection.open
-            cursor.parse(sql)
-            rows_affected = cursor.exec
-            cursor.close
-          end
-          rows_affected
-        end
-
-        alias_method :update, :execute
-        alias_method :delete, :execute
-
-        def begin_db_transaction
-          @connection.commitoff
-        end
-
-        def commit_db_transaction
-          @connection.commit
-          @connection.commiton
-        end
-
-        def rollback_db_transaction
-          @connection.rollback
-          @connection.commiton
-        end
-
-        def quote_column_name(name) name; end
-
-        def quote(value, column = nil)
-          if column && column.type == :timestamp && value.class.to_s == "String"
-            begin
-              value = DateTime.parse(value)
-            rescue => ex
-              # Value cannot be parsed.
-            end
-          end
-
-          case value
-          when String
-            if column && column.type == :binary
-              "'#{quote_string(column.string_to_binary(value))}'" # ' (for ruby-mode)
-            else
-              "'#{quote_string(value)}'" # ' (for ruby-mode)
-            end
-          when NilClass              then "NULL"
-          when TrueClass             then (column && column.type == :boolean ? "'t'" : "1")
-          when FalseClass            then (column && column.type == :boolean ? "'f'" : "0")
-          when Float, Fixnum, Bignum then value.to_s
-          when Date                  then "to_date('#{value.strftime("%Y-%m-%d")}', 'YYYY-MM-DD')" 
-          when Time, DateTime        then "to_date('#{value.strftime("%Y-%m-%d %H:%M:%S")}', 'YYYY-MM-DD HH24:MI:SS')"
-          else                            "'#{quote_string(value.to_yaml)}'"
-          end
-        end
-
-        def quote_string(s)
-          s.gsub(/'/, "''") # ' (for ruby-mode)
-        end
-
-        def add_limit!(sql, limit)
-          l, o = limit.to_s.scan(/\d+/)
-          if o.nil?
-            sql.sub!(/^.*$/im, "select * from (#{sql}) where rownum <= #{l}")
-          else
-            raise ArgumentError, "LIMIT clauses with OFFSET are not supported yet!"
-          end
-        end
-
-        def columns(table_name, name = nil)
-          sql = <<-SQL
-          select column_name,
-                 data_type,
-                 data_length,
-                 data_precision,
-                 data_default
-          from   user_tab_columns
-          where  table_name = upper('#{table_name}')
-          SQL
-          result = []
-          cols = select_all(sql, name)
-          cols.each do |c|
-            name = c['column_name'].downcase
-            default = c['data_default']
-            default = (default == 'NULL') ? nil : default
-            type = get_sql_type(c['data_type'], c['data_length'])
-            result << Column.new(name, default, type)
-          end
-          result
-        end
-
-        private
-
-        def get_sql_type(type_name, type_length)
-          case type_name
-          when /timestamp/i
-            return "TIMESTAMP"
-          when /number/i
-            return "INT"
-          when /date/i
-            return "DATE"
-          else
-            return "#{type_name}(#{type_length})"
-          end
-        end
-
-        def select(sql, name = nil)
-          col_names = []
-          cursor = nil
-          log(sql, name, @connection) do |connection|
-            cursor = connection.open
-            col_names = parse(cursor, sql)
-            cursor.exec
-          end
-
-          rows = []
-          while cursor.fetch do
-            row = {}
-            col_names.each_with_index do |name, i|
-              row[name] = cursor.getCol(i + 1)[0]
-            end
-            rows << row
-          end
-          cursor.close
-          rows
-        end
-
-        VARCHAR2 = 1
-        NUMBER = 2
-        INTEGER = 3 ## external
-        FLOAT = 4   ## external
-        LONG = 8
-        ROWID = 11
-        DATE = 12
-        RAW = 23
-        LONG_RAW = 24
-        UNSIGNED_INT = 68 ## external
-        CHAR = 96
-        MLSLABEL = 105
-
-        def parse(cursor, sql)
-          cursor.parse(sql)
-          colnr = 1
-          col_names = []
-          loop {
-            colinfo = cursor.describe(colnr)
-            break if colinfo.nil?
-
-            col_names << colinfo[2].downcase
-            collength, coltype = colinfo[3], colinfo[1]
-
-            collength, coltype = case coltype
-            when NUMBER
-              [40, VARCHAR2]
-            when VARCHAR2, CHAR
-              [(collength * 1.5).ceil, VARCHAR2]
-            when LONG
-              [65535, LONG]
-            when LONG_RAW
-              [65535, LONG_RAW]
-            else
-              [collength, VARCHAR2]
-            end
-
-            cursor.define(colnr, collength, coltype)
-            colnr += 1
-          }
-          col_names
-        end
-      end
-    end
-  end
-rescue LoadError
-  # Oracle driver is unavailable.
-end