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require 'active_record/connection_adapters/abstract_adapter'
module ActiveRecord
class Base
class << self
# Establishes a connection to the database that's used by all Active Record objects
def sqlite_connection(config) # :nodoc:
parse_sqlite_config!(config)
unless self.class.const_defined?(:SQLite)
require_library_or_gem(config[:adapter])
db = SQLite::Database.new(config[:database], 0)
db.show_datatypes = "ON" if !defined? SQLite::Version
db.results_as_hash = true if defined? SQLite::Version
db.type_translation = false
# "Downgrade" deprecated sqlite API
if SQLite.const_defined?(:Version)
ConnectionAdapters::SQLite2Adapter.new(db, logger)
else
ConnectionAdapters::DeprecatedSQLiteAdapter.new(db, logger)
end
end
end
private
def parse_sqlite_config!(config)
config[:database] ||= config[:dbfile]
# Require database.
unless config[:database]
raise ArgumentError, "No database file specified. Missing argument: database"
end
# Allow database path relative to RAILS_ROOT, but only if
# the database path is not the special path that tells
# Sqlite to build a database only in memory.
if Object.const_defined?(:RAILS_ROOT) && ':memory:' != config[:database]
config[:database] = File.expand_path(config[:database], RAILS_ROOT)
end
end
end
end
module ConnectionAdapters #:nodoc:
class SQLiteColumn < Column #:nodoc:
class << self
def string_to_binary(value)
value.gsub(/\0|\%/n) do |b|
case b
when "\0" then "%00"
when "%" then "%25"
end
end
end
def binary_to_string(value)
value.gsub(/%00|%25/n) do |b|
case b
when "%00" then "\0"
when "%25" then "%"
end
end
end
end
end
# The SQLite adapter works with both the 2.x and 3.x series of SQLite with the sqlite-ruby drivers (available both as gems and
# from http://rubyforge.org/projects/sqlite-ruby/).
#
# Options:
#
# * <tt>:database</tt> -- Path to the database file.
class SQLiteAdapter < AbstractAdapter
def adapter_name #:nodoc:
'SQLite'
end
def supports_migrations? #:nodoc:
true
end
def requires_reloading?
true
end
def disconnect!
super
@connection.close rescue nil
end
def supports_count_distinct? #:nodoc:
sqlite_version >= '3.2.6'
end
def supports_autoincrement? #:nodoc:
sqlite_version >= '3.1.0'
end
def native_database_types #:nodoc:
{
:primary_key => default_primary_key_type,
:string => { :name => "varchar", :limit => 255 },
:text => { :name => "text" },
:integer => { :name => "integer" },
:float => { :name => "float" },
:decimal => { :name => "decimal" },
:datetime => { :name => "datetime" },
:timestamp => { :name => "datetime" },
:time => { :name => "datetime" },
:date => { :name => "date" },
:binary => { :name => "blob" },
:boolean => { :name => "boolean" }
}
end
# QUOTING ==================================================
def quote_string(s) #:nodoc:
@connection.class.quote(s)
end
def quote_column_name(name) #:nodoc:
%Q("#{name}")
end
# DATABASE STATEMENTS ======================================
def execute(sql, name = nil) #:nodoc:
catch_schema_changes { log(sql, name) { @connection.execute(sql) } }
end
def update_sql(sql, name = nil) #:nodoc:
super
@connection.changes
end
def delete_sql(sql, name = nil) #:nodoc:
sql += " WHERE 1=1" unless sql =~ /WHERE/i
super sql, name
end
def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
super || @connection.last_insert_row_id
end
def select_rows(sql, name = nil)
execute(sql, name).map do |row|
(0...(row.size / 2)).map { |i| row[i] }
end
end
def begin_db_transaction #:nodoc:
catch_schema_changes { @connection.transaction }
end
def commit_db_transaction #:nodoc:
catch_schema_changes { @connection.commit }
end
def rollback_db_transaction #:nodoc:
catch_schema_changes { @connection.rollback }
end
# SELECT ... FOR UPDATE is redundant since the table is locked.
def add_lock!(sql, options) #:nodoc:
sql
end
# SCHEMA STATEMENTS ========================================
def tables(name = nil) #:nodoc:
sql = <<-SQL
SELECT name
FROM sqlite_master
WHERE type = 'table' AND NOT name = 'sqlite_sequence'
SQL
execute(sql, name).map do |row|
row[0]
end
end
def columns(table_name, name = nil) #:nodoc:
table_structure(table_name).map do |field|
SQLiteColumn.new(field['name'], field['dflt_value'], field['type'], field['notnull'] == "0")
end
end
def indexes(table_name, name = nil) #:nodoc:
execute("PRAGMA index_list(#{quote_table_name(table_name)})", name).map do |row|
index = IndexDefinition.new(table_name, row['name'])
index.unique = row['unique'] != '0'
index.columns = execute("PRAGMA index_info('#{index.name}')").map { |col| col['name'] }
index
end
end
def primary_key(table_name) #:nodoc:
column = table_structure(table_name).find {|field| field['pk'].to_i == 1}
column ? column['name'] : nil
end
def remove_index(table_name, options={}) #:nodoc:
execute "DROP INDEX #{quote_column_name(index_name(table_name, options))}"
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 = {}) #:nodoc:
super(table_name, column_name, type, options)
# See last paragraph on http://www.sqlite.org/lang_altertable.html
execute "VACUUM"
end
def remove_column(table_name, column_name) #:nodoc:
alter_table(table_name) do |definition|
definition.columns.delete(definition[column_name])
end
end
def change_column_default(table_name, column_name, default) #:nodoc:
alter_table(table_name) do |definition|
definition[column_name].default = default
end
end
def change_column(table_name, column_name, type, options = {}) #:nodoc:
alter_table(table_name) do |definition|
include_default = options_include_default?(options)
definition[column_name].instance_eval do
self.type = type
self.limit = options[:limit] if options.include?(:limit)
self.default = options[:default] if include_default
self.null = options[:null] if options.include?(:null)
end
end
end
def rename_column(table_name, column_name, new_column_name) #:nodoc:
alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
end
def empty_insert_statement(table_name)
"INSERT INTO #{table_name} VALUES(NULL)"
end
protected
def select(sql, name = nil) #:nodoc:
execute(sql, name).map do |row|
record = {}
row.each_key do |key|
if key.is_a?(String)
record[key.sub(/^\w+\./, '')] = row[key]
end
end
record
end
end
def table_structure(table_name)
returning structure = execute("PRAGMA table_info(#{quote_table_name(table_name)})") do
raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
end
end
def alter_table(table_name, options = {}) #:nodoc:
altered_table_name = "altered_#{table_name}"
caller = lambda {|definition| yield definition if block_given?}
transaction do
move_table(table_name, altered_table_name,
options.merge(:temporary => true))
move_table(altered_table_name, table_name, &caller)
end
end
def move_table(from, to, options = {}, &block) #:nodoc:
copy_table(from, to, options, &block)
drop_table(from)
end
def copy_table(from, to, options = {}) #:nodoc:
options = options.merge(:id => !columns(from).detect{|c| c.name == 'id'}.nil?)
create_table(to, options) do |definition|
@definition = definition
columns(from).each do |column|
column_name = options[:rename] ?
(options[:rename][column.name] ||
options[:rename][column.name.to_sym] ||
column.name) : column.name
@definition.column(column_name, column.type,
:limit => column.limit, :default => column.default,
:null => column.null)
end
@definition.primary_key(primary_key(from)) if primary_key(from)
yield @definition if block_given?
end
copy_table_indexes(from, to, options[:rename] || {})
copy_table_contents(from, to,
@definition.columns.map {|column| column.name},
options[:rename] || {})
end
def copy_table_indexes(from, to, rename = {}) #:nodoc:
indexes(from).each do |index|
name = index.name
if to == "altered_#{from}"
name = "temp_#{name}"
elsif from == "altered_#{to}"
name = name[5..-1]
end
to_column_names = columns(to).map(&:name)
columns = index.columns.map {|c| rename[c] || c }.select do |column|
to_column_names.include?(column)
end
unless columns.empty?
# index name can't be the same
opts = { :name => name.gsub(/_(#{from})_/, "_#{to}_") }
opts[:unique] = true if index.unique
add_index(to, columns, opts)
end
end
end
def copy_table_contents(from, to, columns, rename = {}) #:nodoc:
column_mappings = Hash[*columns.map {|name| [name, name]}.flatten]
rename.inject(column_mappings) {|map, a| map[a.last] = a.first; map}
from_columns = columns(from).collect {|col| col.name}
columns = columns.find_all{|col| from_columns.include?(column_mappings[col])}
quoted_columns = columns.map { |col| quote_column_name(col) } * ','
quoted_to = quote_table_name(to)
@connection.execute "SELECT * FROM #{quote_table_name(from)}" do |row|
sql = "INSERT INTO #{quoted_to} (#{quoted_columns}) VALUES ("
sql << columns.map {|col| quote row[column_mappings[col]]} * ', '
sql << ')'
@connection.execute sql
end
end
def catch_schema_changes
return yield
rescue ActiveRecord::StatementInvalid => exception
if exception.message =~ /database schema has changed/
reconnect!
retry
else
raise
end
end
def sqlite_version
@sqlite_version ||= select_value('select sqlite_version(*)')
end
def default_primary_key_type
if supports_autoincrement?
'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'.freeze
else
'INTEGER PRIMARY KEY NOT NULL'.freeze
end
end
end
class SQLite2Adapter < SQLiteAdapter # :nodoc:
def supports_count_distinct? #:nodoc:
false
end
def rename_table(name, new_name)
move_table(name, new_name)
end
def add_column(table_name, column_name, type, options = {}) #:nodoc:
alter_table(table_name) do |definition|
definition.column(column_name, type, options)
end
end
end
class DeprecatedSQLiteAdapter < SQLite2Adapter # :nodoc:
def insert(sql, name = nil, pk = nil, id_value = nil)
execute(sql, name = nil)
id_value || @connection.last_insert_rowid
end
end
end
end
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