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# Author/Maintainer: Maik Schmidt <contact@maik-schmidt.de>
require 'active_record/connection_adapters/abstract_adapter'
begin
require 'db2/db2cli' unless self.class.const_defined?(:DB2CLI)
require 'active_record/vendor/db2'
module ActiveRecord
class Base
# Establishes a connection to the database that's used by
# all Active Record objects
def self.db2_connection(config) # :nodoc:
config = config.symbolize_keys
usr = config[:username]
pwd = config[:password]
schema = config[:schema]
if config.has_key?(:database)
database = config[:database]
else
raise ArgumentError, 'No database specified. Missing argument: database.'
end
connection = DB2::Connection.new(DB2::Environment.new)
connection.connect(database, usr, pwd)
ConnectionAdapters::DB2Adapter.new(connection, logger, :schema => schema)
end
end
module ConnectionAdapters
# The DB2 adapter works with the C-based CLI driver (http://rubyforge.org/projects/ruby-dbi/)
#
# Options:
#
# * <tt>:username</tt> -- Defaults to nothing
# * <tt>:password</tt> -- Defaults to nothing
# * <tt>:database</tt> -- The name of the database. No default, must be provided.
# * <tt>:schema</tt> -- Database schema to be set initially.
class DB2Adapter < AbstractAdapter
def initialize(connection, logger, connection_options)
super(connection, logger)
@connection_options = connection_options
if schema = @connection_options[:schema]
with_statement do |stmt|
stmt.exec_direct("SET SCHEMA=#{schema}")
end
end
end
def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
execute(sql, name = nil)
id_value || last_insert_id
end
def execute(sql, name = nil)
rows_affected = 0
with_statement do |stmt|
log(sql, name) do
stmt.exec_direct(sql)
rows_affected = stmt.row_count
end
end
rows_affected
end
def begin_db_transaction
@connection.set_auto_commit_off
end
def commit_db_transaction
@connection.commit
@connection.set_auto_commit_on
end
def rollback_db_transaction
@connection.rollback
@connection.set_auto_commit_on
end
def quote_column_name(column_name)
column_name
end
def adapter_name()
'DB2'
end
def quote_string(string)
string.gsub(/'/, "''") # ' (for ruby-mode)
end
def add_limit_offset!(sql, options)
if limit = options[:limit]
offset = options[:offset] || 0
# The following trick was added by andrea+rails@webcom.it.
sql.gsub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT')
sql << ") A ) B WHERE B.internal$rownum > #{offset} AND B.internal$rownum <= #{limit + offset}"
end
end
def tables(name = nil)
result = []
schema = @connection_options[:schema] || '%'
with_statement do |stmt|
stmt.tables(schema).each { |t| result << t[2].downcase }
end
result
end
def indexes(table_name, name = nil)
tmp = {}
schema = @connection_options[:schema] || ''
with_statement do |stmt|
stmt.indexes(table_name, schema).each do |t|
next unless t[5]
next if t[4] == 'SYSIBM' # Skip system indexes.
idx_name = t[5].downcase
col_name = t[8].downcase
if tmp.has_key?(idx_name)
tmp[idx_name].columns << col_name
else
is_unique = t[3] == 0
tmp[idx_name] = IndexDefinition.new(table_name, idx_name, is_unique, [col_name])
end
end
end
tmp.values
end
def columns(table_name, name = nil)
result = []
schema = @connection_options[:schema] || '%'
with_statement do |stmt|
stmt.columns(table_name, schema).each do |c|
c_name = c[3].downcase
c_default = c[12] == 'NULL' ? nil : c[12]
c_default.gsub!(/^'(.*)'$/, '\1') if !c_default.nil?
c_type = c[5].downcase
c_type += "(#{c[6]})" if !c[6].nil? && c[6] != ''
result << Column.new(c_name, c_default, c_type, c[17] == 'YES')
end
end
result
end
def native_database_types
{
:primary_key => 'int generated by default as identity (start with 42) primary key',
:string => { :name => 'varchar', :limit => 255 },
:text => { :name => 'clob', :limit => 32768 },
:integer => { :name => 'int' },
:float => { :name => 'float' },
:decimal => { :name => 'decimal' },
:datetime => { :name => 'timestamp' },
:timestamp => { :name => 'timestamp' },
:time => { :name => 'time' },
:date => { :name => 'date' },
:binary => { :name => 'blob', :limit => 32768 },
:boolean => { :name => 'decimal', :limit => 1 }
}
end
def quoted_true
'1'
end
def quoted_false
'0'
end
def active?
@connection.select_one 'select 1 from ibm.sysdummy1'
true
rescue Exception
false
end
def reconnect!
end
def table_alias_length
128
end
private
def with_statement
stmt = DB2::Statement.new(@connection)
yield stmt
stmt.free
end
def last_insert_id
row = select_one(<<-GETID.strip)
with temp(id) as (values (identity_val_local())) select * from temp
GETID
row['id'].to_i
end
def select(sql, name = nil)
rows = []
with_statement do |stmt|
log(sql, name) do
stmt.exec_direct("#{sql.gsub(/=\s*null/i, 'IS NULL')} with ur")
end
while row = stmt.fetch_as_hash
row.delete('internal$rownum')
rows << row
end
end
rows
end
end
end
end
rescue LoadError
# DB2 driver is unavailable.
module ActiveRecord # :nodoc:
class Base
def self.db2_connection(config) # :nodoc:
# Set up a reasonable error message
raise LoadError, "DB2 Libraries could not be loaded."
end
end
end
end
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