Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Tag: v1.1.4
Fetching contributors…

Cannot retrieve contributors at this time

508 lines (438 sloc) 18.384 kB
require 'active_record/connection_adapters/abstract_adapter'
module ActiveRecord
class Base
# Establishes a connection to the database that's used by all Active Record objects
def self.postgresql_connection(config) # :nodoc:
require_library_or_gem 'postgres' unless self.class.const_defined?(:PGconn)
config = config.symbolize_keys
host = config[:host]
port = config[:port] || 5432 unless host.nil?
username = config[:username].to_s
password = config[:password].to_s
min_messages = config[:min_messages]
if config.has_key?(:database)
database = config[:database]
else
raise ArgumentError, "No database specified. Missing argument: database."
end
pga = ConnectionAdapters::PostgreSQLAdapter.new(
PGconn.connect(host, port, "", "", database, username, password), logger, config
)
PGconn.translate_results = false if PGconn.respond_to? :translate_results=
pga.schema_search_path = config[:schema_search_path] || config[:schema_order]
pga
end
end
module ConnectionAdapters
# The PostgreSQL adapter works both with the C-based (http://www.postgresql.jp/interfaces/ruby/) and the Ruby-base
# (available both as gem and from http://rubyforge.org/frs/?group_id=234&release_id=1145) drivers.
#
# Options:
#
# * <tt>:host</tt> -- Defaults to localhost
# * <tt>:port</tt> -- Defaults to 5432
# * <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_search_path</tt> -- An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the :schema_order option.
# * <tt>:encoding</tt> -- An optional client encoding that is using in a SET client_encoding TO <encoding> call on connection.
# * <tt>:min_messages</tt> -- An optional client min messages that is using in a SET client_min_messages TO <min_messages> call on connection.
class PostgreSQLAdapter < AbstractAdapter
def adapter_name
'PostgreSQL'
end
def initialize(connection, logger, config = {})
super(connection, logger)
@config = config
configure_connection
end
# Is this connection alive and ready for queries?
def active?
if @connection.respond_to?(:status)
@connection.status == PGconn::CONNECTION_OK
else
@connection.query 'SELECT 1'
true
end
# postgres-pr raises a NoMethodError when querying if no conn is available
rescue PGError, NoMethodError
false
end
# Close then reopen the connection.
def reconnect!
# TODO: postgres-pr doesn't have PGconn#reset.
if @connection.respond_to?(:reset)
@connection.reset
configure_connection
end
end
def disconnect!
# Both postgres and postgres-pr respond to :close
@connection.close rescue nil
end
def native_database_types
{
:primary_key => "serial primary key",
:string => { :name => "character varying", :limit => 255 },
:text => { :name => "text" },
:integer => { :name => "integer" },
:float => { :name => "float" },
:datetime => { :name => "timestamp" },
:timestamp => { :name => "timestamp" },
:time => { :name => "time" },
:date => { :name => "date" },
:binary => { :name => "bytea" },
:boolean => { :name => "boolean" }
}
end
def supports_migrations?
true
end
def table_alias_length
63
end
# QUOTING ==================================================
def quote(value, column = nil)
if value.kind_of?(String) && column && column.type == :binary
"'#{escape_bytea(value)}'"
else
super
end
end
def quote_column_name(name)
%("#{name}")
end
# DATABASE STATEMENTS ======================================
def select_all(sql, name = nil) #:nodoc:
select(sql, name)
end
def select_one(sql, name = nil) #:nodoc:
result = select(sql, name)
result.first if result
end
def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
execute(sql, name)
table = sql.split(" ", 4)[2]
id_value || last_insert_id(table, sequence_name || default_sequence_name(table, pk))
end
def query(sql, name = nil) #:nodoc:
log(sql, name) { @connection.query(sql) }
end
def execute(sql, name = nil) #:nodoc:
log(sql, name) { @connection.exec(sql) }
end
def update(sql, name = nil) #:nodoc:
execute(sql, name).cmdtuples
end
alias_method :delete, :update #:nodoc:
def begin_db_transaction #:nodoc:
execute "BEGIN"
end
def commit_db_transaction #:nodoc:
execute "COMMIT"
end
def rollback_db_transaction #:nodoc:
execute "ROLLBACK"
end
# SCHEMA STATEMENTS ========================================
# Return the list of all tables in the schema search path.
def tables(name = nil) #:nodoc:
schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
query(<<-SQL, name).map { |row| row[0] }
SELECT tablename
FROM pg_tables
WHERE schemaname IN (#{schemas})
SQL
end
def indexes(table_name, name = nil) #:nodoc:
result = query(<<-SQL, name)
SELECT i.relname, d.indisunique, a.attname
FROM pg_class t, pg_class i, pg_index d, pg_attribute a
WHERE i.relkind = 'i'
AND d.indexrelid = i.oid
AND d.indisprimary = 'f'
AND t.oid = d.indrelid
AND t.relname = '#{table_name}'
AND a.attrelid = t.oid
AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum
OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum
OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum
OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum
OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )
ORDER BY i.relname
SQL
current_index = nil
indexes = []
result.each do |row|
if current_index != row[0]
indexes << IndexDefinition.new(table_name, row[0], row[1] == "t", [])
current_index = row[0]
end
indexes.last.columns << row[2]
end
indexes
end
def columns(table_name, name = nil) #:nodoc:
column_definitions(table_name).collect do |name, type, default, notnull|
Column.new(name, default_value(default), translate_field_type(type),
notnull == "f")
end
end
# Set the schema search path to a string of comma-separated schema names.
# Names beginning with $ are quoted (e.g. $user => '$user')
# See http://www.postgresql.org/docs/8.0/interactive/ddl-schemas.html
def schema_search_path=(schema_csv) #:nodoc:
if schema_csv
execute "SET search_path TO #{schema_csv}"
@schema_search_path = nil
end
end
def schema_search_path #:nodoc:
@schema_search_path ||= query('SHOW search_path')[0][0]
end
def default_sequence_name(table_name, pk = nil)
default_pk, default_seq = pk_and_sequence_for(table_name)
default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq"
end
# Resets sequence to the max value of the table's pk if present.
def reset_pk_sequence!(table, pk = nil, sequence = nil)
unless pk and sequence
default_pk, default_sequence = pk_and_sequence_for(table)
pk ||= default_pk
sequence ||= default_sequence
end
if pk
if sequence
select_value <<-end_sql, 'Reset sequence'
SELECT setval('#{sequence}', (SELECT COALESCE(MAX(#{pk})+(SELECT increment_by FROM #{sequence}), (SELECT min_value FROM #{sequence})) FROM #{table}), false)
end_sql
else
@logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger
end
end
end
# Find a table's primary key and sequence.
def pk_and_sequence_for(table)
# First try looking for a sequence with a dependency on the
# given table's primary key.
result = execute(<<-end_sql, 'PK and serial sequence')[0]
SELECT attr.attname, name.nspname, seq.relname
FROM pg_class seq,
pg_attribute attr,
pg_depend dep,
pg_namespace name,
pg_constraint cons
WHERE seq.oid = dep.objid
AND seq.relnamespace = name.oid
AND seq.relkind = 'S'
AND attr.attrelid = dep.refobjid
AND attr.attnum = dep.refobjsubid
AND attr.attrelid = cons.conrelid
AND attr.attnum = cons.conkey[1]
AND cons.contype = 'p'
AND dep.refobjid = '#{table}'::regclass
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).
# TODO: assumes sequence is in same schema as table.
result = execute(<<-end_sql, 'PK and custom sequence')[0]
SELECT attr.attname, name.nspname, split_part(def.adsrc, '\\\'', 2)
FROM pg_class t
JOIN pg_namespace name ON (t.relnamespace = name.oid)
JOIN pg_attribute attr ON (t.oid = attrelid)
JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum)
JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1])
WHERE t.oid = '#{table}'::regclass
AND cons.contype = 'p'
AND def.adsrc ~* 'nextval'
end_sql
end
# check for existence of . in sequence name as in public.foo_sequence. if it does not exist, join the current namespace
result.last['.'] ? [result.first, result.last] : [result.first, "#{result[1]}.#{result[2]}"]
rescue
nil
end
def rename_table(name, new_name)
execute "ALTER TABLE #{name} RENAME TO #{new_name}"
end
def add_column(table_name, column_name, type, options = {})
execute("ALTER TABLE #{table_name} ADD #{column_name} #{type_to_sql(type, options[:limit])}")
execute("ALTER TABLE #{table_name} ALTER #{column_name} SET NOT NULL") if options[:null] == false
change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
end
def change_column(table_name, column_name, type, options = {}) #:nodoc:
begin
execute "ALTER TABLE #{table_name} ALTER #{column_name} TYPE #{type_to_sql(type, options[:limit])}"
rescue ActiveRecord::StatementInvalid
# This is PG7, so we use a more arcane way of doing it.
begin_db_transaction
add_column(table_name, "#{column_name}_ar_tmp", type, options)
execute "UPDATE #{table_name} SET #{column_name}_ar_tmp = CAST(#{column_name} AS #{type_to_sql(type, options[:limit])})"
remove_column(table_name, column_name)
rename_column(table_name, "#{column_name}_ar_tmp", column_name)
commit_db_transaction
end
change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
end
def change_column_default(table_name, column_name, default) #:nodoc:
execute "ALTER TABLE #{table_name} ALTER COLUMN #{column_name} SET DEFAULT '#{default}'"
end
def rename_column(table_name, column_name, new_column_name) #:nodoc:
execute "ALTER TABLE #{table_name} RENAME COLUMN #{column_name} TO #{new_column_name}"
end
def remove_index(table_name, options) #:nodoc:
execute "DROP INDEX #{index_name(table_name, options)}"
end
private
BYTEA_COLUMN_TYPE_OID = 17
TIMESTAMPOID = 1114
TIMESTAMPTZOID = 1184
def configure_connection
if @config[:encoding]
execute("SET client_encoding TO '#{@config[:encoding]}'")
end
if @config[:min_messages]
execute("SET client_min_messages TO '#{@config[:min_messages]}'")
end
end
def last_insert_id(table, sequence_name)
Integer(select_value("SELECT currval('#{sequence_name}')"))
end
def select(sql, name = nil)
res = execute(sql, name)
results = res.result
rows = []
if results.length > 0
fields = res.fields
results.each do |row|
hashed_row = {}
row.each_index do |cel_index|
column = row[cel_index]
case res.type(cel_index)
when BYTEA_COLUMN_TYPE_OID
column = unescape_bytea(column)
when TIMESTAMPTZOID, TIMESTAMPOID
column = cast_to_time(column)
end
hashed_row[fields[cel_index]] = column
end
rows << hashed_row
end
end
return rows
end
def escape_bytea(s)
if PGconn.respond_to? :escape_bytea
self.class.send(:define_method, :escape_bytea) do |s|
PGconn.escape_bytea(s) if s
end
else
self.class.send(:define_method, :escape_bytea) do |s|
if s
result = ''
s.each_byte { |c| result << sprintf('\\\\%03o', c) }
result
end
end
end
escape_bytea(s)
end
def unescape_bytea(s)
if PGconn.respond_to? :unescape_bytea
self.class.send(:define_method, :unescape_bytea) do |s|
PGconn.unescape_bytea(s) if s
end
else
self.class.send(:define_method, :unescape_bytea) do |s|
if s
result = ''
i, max = 0, s.size
while i < max
char = s[i]
if char == ?\\
if s[i+1] == ?\\
char = ?\\
i += 1
else
char = s[i+1..i+3].oct
i += 3
end
end
result << char
i += 1
end
result
end
end
end
unescape_bytea(s)
end
# Query a table's column names, default values, and types.
#
# The underlying query is roughly:
# SELECT column.name, column.type, default.value
# FROM column LEFT JOIN default
# ON column.table_id = default.table_id
# AND column.num = default.column_num
# WHERE column.table_id = get_table_id('table_name')
# AND column.num > 0
# AND NOT column.is_dropped
# ORDER BY column.num
#
# If the table name is not prefixed with a schema, the database will
# take the first match from the schema search path.
#
# Query implementation notes:
# - format_type includes the column size constraint, e.g. varchar(50)
# - ::regclass is a function that gives the id for a table name
def column_definitions(table_name)
query <<-end_sql
SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
FROM pg_attribute a LEFT JOIN pg_attrdef d
ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attrelid = '#{table_name}'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
end_sql
end
# Translate PostgreSQL-specific types into simplified SQL types.
# These are special cases; standard types are handled by
# ConnectionAdapters::Column#simplified_type.
def translate_field_type(field_type)
# Match the beginning of field_type since it may have a size constraint on the end.
case field_type
when /^timestamp/i then 'datetime'
when /^real|^money/i then 'float'
when /^interval/i then 'string'
# geometric types (the line type is currently not implemented in postgresql)
when /^(?:point|lseg|box|"?path"?|polygon|circle)/i then 'string'
when /^bytea/i then 'binary'
else field_type # Pass through standard types.
end
end
def default_value(value)
# Boolean types
return "t" if value =~ /true/i
return "f" if value =~ /false/i
# Char/String/Bytea type values
return $1 if value =~ /^'(.*)'::(bpchar|text|character varying|bytea)$/
# Numeric values
return value if value =~ /^-?[0-9]+(\.[0-9]*)?/
# Fixed dates / times
return $1 if value =~ /^'(.+)'::(date|timestamp)/
# Anything else is blank, some user type, or some function
# and we can't know the value of that, so return nil.
return nil
end
# Only needed for DateTime instances
def cast_to_time(value)
return value unless value.class == DateTime
v = value
time_array = [v.year, v.month, v.day, v.hour, v.min, v.sec]
Time.send(Base.default_timezone, *time_array) rescue nil
end
end
end
end
Jump to Line
Something went wrong with that request. Please try again.