require 'active_record/connection_adapters/abstract_adapter'
# sqlserver_adapter.rb -- ActiveRecord adapter for Microsoft SQL Server
#
# Author: Joey Gibson <joey@joeygibson.com>
# Date: 10/14/2004
#
# REQUIREMENTS:
#
# This adapter will ONLY work on Windows systems, since it relies on Win32OLE, which,
# to my knowledge, is only available on Window.
#
# It relies on the ADO support in the DBI module. If you are using the
# one-click installer of Ruby, then you already have DBI installed, but
# the ADO module is *NOT* installed. You will need to get the latest
# source distribution of Ruby-DBI from http://ruby-dbi.sourceforge.net/
# unzip it, and copy the file src/lib/dbd_ado/ADO.rb to
# X:/Ruby/lib/ruby/site_ruby/1.8/DBD/ADO/ADO.rb (you will need to create
# the ADO directory). Once you've installed that file, you are ready to go.
#
# This module uses the ADO-style DSNs for connection. For example:
# "DBI:ADO:Provider=SQLOLEDB;Data Source=(local);Initial Catalog=test;User Id=sa;Password=password;"
# with User Id replaced with your proper login, and Password with your
# password.
#
# I have tested this code on a WindowsXP Pro SP1 system,
# ruby 1.8.2 (2004-07-29) [i386-mswin32], SQL Server 2000.
#
module ActiveRecord
class Base
def self.sqlserver_connection(config)
require_library_or_gem 'dbi' unless self.class.const_defined?(:DBI)
class_eval { include ActiveRecord::SQLServerBaseExtensions }
symbolize_strings_in_hash(config)
if config.has_key? :dsn
dsn = config[:dsn]
else
raise ArgumentError, "No DSN specified"
end
conn = DBI.connect(dsn)
conn["AutoCommit"] = true
ConnectionAdapters::SQLServerAdapter.new(conn, logger)
end
end
module SQLServerBaseExtensions #:nodoc:
def self.append_features(base)
super
base.extend(ClassMethods)
end
module ClassMethods
def find_first(conditions = nil, orderings = nil)
sql = "SELECT TOP 1 * FROM #{table_name} "
add_conditions!(sql, conditions)
sql << "ORDER BY #{orderings} " unless orderings.nil?
record = connection.select_one(sql, "#{name} Load First")
instantiate(record) unless record.nil?
end
def find_all(conditions = nil, orderings = nil, limit = nil, joins = nil)
sql = "SELECT "
sql << "TOP #{limit} " unless limit.nil?
sql << " * FROM #{table_name} "
sql << "#{joins} " if joins
add_conditions!(sql, conditions)
sql << "ORDER BY #{orderings} " unless orderings.nil?
find_by_sql(sql)
end
end
def attributes_with_quotes
columns_hash = self.class.columns_hash
attrs = @attributes.dup
attrs = attrs.reject do |name, value|
columns_hash[name].identity
end
attrs.inject({}) do |attrs_quoted, pair|
attrs_quoted[pair.first] = quote(pair.last, columns_hash[pair.first])
attrs_quoted
end
end
end
module ConnectionAdapters
class ColumnWithIdentity < Column
attr_reader :identity
def initialize(name, default, sql_type = nil, is_identity = false)
super(name, default, sql_type)
@identity = is_identity
end
end
class SQLServerAdapter < AbstractAdapter # :nodoc:
def quote_column_name(name)
" [#{name}] "
end
def select_all(sql, name = nil)
select(sql, name)
end
def select_one(sql, name = nil)
result = select(sql, name)
result.nil? ? nil : result.first
end
def columns(table_name, name = nil)
sql = <<EOL
SELECT s.name AS TableName, c.id AS ColId, c.name AS ColName, t.name AS ColType, c.length AS Length,
c.AutoVal AS IsIdentity,
c.cdefault AS DefaultId, com.text AS DefaultValue
FROM syscolumns AS c
JOIN systypes AS t ON (c.xtype = t.xtype AND c.usertype = t.usertype)
JOIN sysobjects AS s ON (c.id = s.id)
LEFT OUTER JOIN syscomments AS com ON (c.cdefault = com.id)
WHERE s.name = '#{table_name}'
EOL
columns = []
log(sql, name, @connection) do |conn|
conn.select_all(sql) do |row|
default_value = row[:DefaultValue]
if default_value =~ /null/i
default_value = nil
else
default_value =~ /\(([^)]+)\)/
default_value = $1
end
col = ColumnWithIdentity.new(row[:ColName], default_value, "#{row[:ColType]}(#{row[:Length]})", row[:IsIdentity] != nil)
columns << col
end
end
columns
end
def insert(sql, name = nil, pk = nil, id_value = nil)
begin
table_name = get_table_name(sql)
col = get_identity_column(table_name)
ii_enabled = false
if col != nil
if query_contains_identity_column(sql, col)
begin
execute enable_identity_insert(table_name, true)
ii_enabled = true
rescue Exception => e
# Coulnd't turn on IDENTITY_INSERT
end
end
end
log(sql, name, @connection) do |conn|
conn.execute(sql)
select_one("SELECT @@IDENTITY AS Ident")["Ident"]
end
ensure
if ii_enabled
begin
execute enable_identity_insert(table_name, false)
rescue Exception => e
# Couldn't turn off IDENTITY_INSERT
end
end
end
end
def execute(sql, name = nil)
if sql =~ /^INSERT/i
insert(sql, name)
else
log(sql, name, @connection) do |conn|
conn.execute(sql)
end
end
end
alias_method :update, :execute
alias_method :delete, :execute
def begin_db_transaction
begin
@connection["AutoCommit"] = false
rescue Exception => e
@connection["AutoCommit"] = true
end
end
def commit_db_transaction
begin
@connection.commit
ensure
@connection["AutoCommit"] = true
end
end
def rollback_db_transaction
begin
@connection.rollback
ensure
@connection["AutoCommit"] = true
end
end
def recreate_database(name)
drop_database(name)
create_database(name)
end
def drop_database(name)
execute "DROP DATABASE #{name}"
end
def create_database(name)
execute "CREATE DATABASE #{name}"
end
private
def select(sql, name = nil)
rows = []
log(sql, name, @connection) do |conn|
conn.select_all(sql) do |row|
record = {}
row.column_names.each do |col|
record[col] = row[col]
end
rows << record
end
end
rows
end
def enable_identity_insert(table_name, enable = true)
if has_identity_column(table_name)
"SET IDENTITY_INSERT #{table_name} #{enable ? 'ON' : 'OFF'}"
end
end
def get_table_name(sql)
if sql =~ /into\s*([^\s]+)\s*/i or
sql =~ /update\s*([^\s]+)\s*/i
$1
else
nil
end
end
def has_identity_column(table_name)
return get_identity_column(table_name) != nil
end
def get_identity_column(table_name)
if not @table_columns
@table_columns = {}
end
if @table_columns[table_name] == nil
@table_columns[table_name] = columns(table_name)
end
@table_columns[table_name].each do |col|
return col.name if col.identity
end
return nil
end
def query_contains_identity_column(sql, col)
return sql =~ /[\(\.\,]\s*#{col}/
end
end
end
end