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require 'active_record/connection_adapters/abstract_adapter'
require 'active_record/connection_adapters/statement_pool'
require 'active_record/connection_adapters/sqlite3/schema_creation'
gem 'sqlite3', '~> 1.3.6'
require 'sqlite3'
module ActiveRecord
module ConnectionHandling # :nodoc:
# sqlite3 adapter reuses sqlite_connection.
def sqlite3_connection(config)
# 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 ':memory:' != config[:database]
config[:database] = File.expand_path(config[:database], Rails.root) if defined?(Rails.root)
dirname = File.dirname(config[:database])
Dir.mkdir(dirname) unless File.directory?(dirname)
end
db = SQLite3::Database.new(
config[:database].to_s,
:results_as_hash => true
)
db.busy_timeout(ConnectionAdapters::SQLite3Adapter.type_cast_config_to_integer(config[:timeout])) if config[:timeout]
ConnectionAdapters::SQLite3Adapter.new(db, logger, nil, config)
rescue Errno::ENOENT => error
if error.message.include?("No such file or directory")
raise ActiveRecord::NoDatabaseError.new(error.message, error)
else
raise
end
end
end
module ConnectionAdapters #:nodoc:
# The SQLite3 adapter works SQLite 3.6.16 or newer
# with the sqlite3-ruby drivers (available as gem from https://rubygems.org/gems/sqlite3).
#
# Options:
#
# * <tt>:database</tt> - Path to the database file.
class SQLite3Adapter < AbstractAdapter
ADAPTER_NAME = 'SQLite'.freeze
include Savepoints
NATIVE_DATABASE_TYPES = {
primary_key: 'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL',
string: { name: "varchar" },
text: { name: "text" },
integer: { name: "integer" },
float: { name: "float" },
decimal: { name: "decimal" },
datetime: { name: "datetime" },
time: { name: "time" },
date: { name: "date" },
binary: { name: "blob" },
boolean: { name: "boolean" }
}
class StatementPool < ConnectionAdapters::StatementPool
private
def dealloc(stmt)
stmt[:stmt].close unless stmt[:stmt].closed?
end
end
def schema_creation # :nodoc:
SQLite3::SchemaCreation.new self
end
def initialize(connection, logger, connection_options, config)
super(connection, logger)
@active = nil
@statements = StatementPool.new(self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 }))
@config = config
@visitor = Arel::Visitors::SQLite.new self
@quoted_column_names = {}
if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
@prepared_statements = true
else
@prepared_statements = false
end
end
def supports_ddl_transactions?
true
end
def supports_savepoints?
true
end
def supports_partial_index?
sqlite_version >= '3.8.0'
end
# Returns true, since this connection adapter supports prepared statement
# caching.
def supports_statement_cache?
true
end
# Returns true, since this connection adapter supports migrations.
def supports_migrations? #:nodoc:
true
end
def supports_primary_key? #:nodoc:
true
end
def requires_reloading?
true
end
def supports_views?
true
end
def active?
@active != false
end
# Disconnects from the database if already connected. Otherwise, this
# method does nothing.
def disconnect!
super
@active = false
@connection.close rescue nil
end
# Clears the prepared statements cache.
def clear_cache!
@statements.clear
end
def supports_index_sort_order?
true
end
# Returns 62. SQLite supports index names up to 64
# characters. The rest is used by rails internally to perform
# temporary rename operations
def allowed_index_name_length
index_name_length - 2
end
def native_database_types #:nodoc:
NATIVE_DATABASE_TYPES
end
# Returns the current database encoding format as a string, eg: 'UTF-8'
def encoding
@connection.encoding.to_s
end
def supports_explain?
true
end
# QUOTING ==================================================
def _quote(value) # :nodoc:
case value
when Type::Binary::Data
"x'#{value.hex}'"
else
super
end
end
def _type_cast(value) # :nodoc:
case value
when BigDecimal
value.to_f
when String
if value.encoding == Encoding::ASCII_8BIT
super(value.encode(Encoding::UTF_8))
else
super
end
else
super
end
end
def quote_string(s) #:nodoc:
@connection.class.quote(s)
end
def quote_table_name_for_assignment(table, attr)
quote_column_name(attr)
end
def quote_column_name(name) #:nodoc:
@quoted_column_names[name] ||= %Q("#{name.to_s.gsub('"', '""')}")
end
#--
# DATABASE STATEMENTS ======================================
#++
def explain(arel, binds = [])
sql = "EXPLAIN QUERY PLAN #{to_sql(arel, binds)}"
ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', []))
end
class ExplainPrettyPrinter
# Pretty prints the result of a EXPLAIN QUERY PLAN in a way that resembles
# the output of the SQLite shell:
#
# 0|0|0|SEARCH TABLE users USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)
# 0|1|1|SCAN TABLE posts (~100000 rows)
#
def pp(result) # :nodoc:
result.rows.map do |row|
row.join('|')
end.join("\n") + "\n"
end
end
def exec_query(sql, name = nil, binds = [])
type_casted_binds = binds.map { |attr| type_cast(attr.value_for_database) }
log(sql, name, binds) do
# Don't cache statements if they are not prepared
if without_prepared_statement?(binds)
stmt = @connection.prepare(sql)
begin
cols = stmt.columns
records = stmt.to_a
ensure
stmt.close
end
stmt = records
else
cache = @statements[sql] ||= {
:stmt => @connection.prepare(sql)
}
stmt = cache[:stmt]
cols = cache[:cols] ||= stmt.columns
stmt.reset!
stmt.bind_params type_casted_binds
end
ActiveRecord::Result.new(cols, stmt.to_a)
end
end
def exec_delete(sql, name = 'SQL', binds = [])
exec_query(sql, name, binds)
@connection.changes
end
alias :exec_update :exec_delete
def last_inserted_id(result)
@connection.last_insert_row_id
end
def execute(sql, name = nil) #:nodoc:
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
id_value || @connection.last_insert_row_id
end
alias :create :insert_sql
def select_rows(sql, name = nil, binds = [])
exec_query(sql, name, binds).rows
end
def begin_db_transaction #:nodoc:
log('begin transaction',nil) { @connection.transaction }
end
def commit_db_transaction #:nodoc:
log('commit transaction',nil) { @connection.commit }
end
def exec_rollback_db_transaction #:nodoc:
log('rollback transaction',nil) { @connection.rollback }
end
# SCHEMA STATEMENTS ========================================
def tables(name = nil, table_name = nil) #:nodoc:
sql = <<-SQL
SELECT name
FROM sqlite_master
WHERE (type = 'table' OR type = 'view') AND NOT name = 'sqlite_sequence'
SQL
sql << " AND name = #{quote_table_name(table_name)}" if table_name
exec_query(sql, 'SCHEMA').map do |row|
row['name']
end
end
def table_exists?(table_name)
table_name && tables(nil, table_name).any?
end
# Returns an array of +Column+ objects for the table specified by +table_name+.
def columns(table_name) #:nodoc:
table_structure(table_name).map do |field|
case field["dflt_value"]
when /^null$/i
field["dflt_value"] = nil
when /^'(.*)'$/m
field["dflt_value"] = $1.gsub("''", "'")
when /^"(.*)"$/m
field["dflt_value"] = $1.gsub('""', '"')
end
collation = field['collation']
sql_type = field['type']
type_metadata = fetch_type_metadata(sql_type)
new_column(field['name'], field['dflt_value'], type_metadata, field['notnull'].to_i == 0, nil, collation)
end
end
# Returns an array of indexes for the given table.
def indexes(table_name, name = nil) #:nodoc:
exec_query("PRAGMA index_list(#{quote_table_name(table_name)})", 'SCHEMA').map do |row|
sql = <<-SQL
SELECT sql
FROM sqlite_master
WHERE name=#{quote(row['name'])} AND type='index'
UNION ALL
SELECT sql
FROM sqlite_temp_master
WHERE name=#{quote(row['name'])} AND type='index'
SQL
index_sql = exec_query(sql).first['sql']
match = /\sWHERE\s+(.+)$/i.match(index_sql)
where = match[1] if match
IndexDefinition.new(
table_name,
row['name'],
row['unique'] != 0,
exec_query("PRAGMA index_info('#{row['name']}')", "SCHEMA").map { |col|
col['name']
}, nil, nil, where)
end
end
def primary_key(table_name) #:nodoc:
pks = table_structure(table_name).select { |f| f['pk'] > 0 }
return nil unless pks.count == 1
pks[0]['name']
end
def remove_index(table_name, options = {}) #:nodoc:
index_name = index_name_for_remove(table_name, options)
exec_query "DROP INDEX #{quote_column_name(index_name)}"
end
# Renames a table.
#
# Example:
# rename_table('octopuses', 'octopi')
def rename_table(table_name, new_name)
exec_query "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
rename_table_indexes(table_name, new_name)
end
# See: http://www.sqlite.org/lang_altertable.html
# SQLite has an additional restriction on the ALTER TABLE statement
def valid_alter_table_type?(type)
type.to_sym != :primary_key
end
def add_column(table_name, column_name, type, options = {}) #:nodoc:
if valid_alter_table_type?(type)
super(table_name, column_name, type, options)
else
alter_table(table_name) do |definition|
definition.column(column_name, type, options)
end
end
end
def remove_column(table_name, column_name, type = nil, options = {}) #:nodoc:
alter_table(table_name) do |definition|
definition.remove_column column_name
end
end
def change_column_default(table_name, column_name, default_or_changes) #:nodoc:
default = extract_new_default_value(default_or_changes)
alter_table(table_name) do |definition|
definition[column_name].default = default
end
end
def change_column_null(table_name, column_name, null, default = nil) #:nodoc:
unless null || default.nil?
exec_query("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
end
alter_table(table_name) do |definition|
definition[column_name].null = null
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)
self.precision = options[:precision] if options.include?(:precision)
self.scale = options[:scale] if options.include?(:scale)
self.collation = options[:collation] if options.include?(:collation)
end
end
end
def rename_column(table_name, column_name, new_column_name) #:nodoc:
column = column_for(table_name, column_name)
alter_table(table_name, rename: {column.name => new_column_name.to_s})
rename_column_indexes(table_name, column.name, new_column_name)
end
protected
def table_structure(table_name)
structure = exec_query("PRAGMA table_info(#{quote_table_name(table_name)})", 'SCHEMA')
raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
table_structure_with_collation(table_name, structure)
end
def alter_table(table_name, options = {}) #:nodoc:
altered_table_name = "a#{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:
from_primary_key = primary_key(from)
options[:id] = false
create_table(to, options) do |definition|
@definition = definition
@definition.primary_key(from_primary_key) if from_primary_key.present?
columns(from).each do |column|
column_name = options[:rename] ?
(options[:rename][column.name] ||
options[:rename][column.name.to_sym] ||
column.name) : column.name
next if column_name == from_primary_key
@definition.column(column_name, column.type,
:limit => column.limit, :default => column.default,
:precision => column.precision, :scale => column.scale,
:null => column.null, collation: column.collation)
end
yield @definition if block_given?
end
copy_table_indexes(from, to, options[:rename] || {})
copy_table_contents(from, to,
@definition.columns.map(&:name),
options[:rename] || {})
end
def copy_table_indexes(from, to, rename = {}) #:nodoc:
indexes(from).each do |index|
name = index.name
if to == "a#{from}"
name = "t#{name}"
elsif from == "a#{to}"
name = name[1..-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})_/, "\\1#{to}_"), internal: true }
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]}]
rename.each { |a| column_mappings[a.last] = a.first }
from_columns = columns(from).collect(&:name)
columns = columns.find_all{|col| from_columns.include?(column_mappings[col])}
from_columns_to_copy = columns.map { |col| column_mappings[col] }
quoted_columns = columns.map { |col| quote_column_name(col) } * ','
quoted_from_columns = from_columns_to_copy.map { |col| quote_column_name(col) } * ','
exec_query("INSERT INTO #{quote_table_name(to)} (#{quoted_columns})
SELECT #{quoted_from_columns} FROM #{quote_table_name(from)}")
end
def sqlite_version
@sqlite_version ||= SQLite3Adapter::Version.new(select_value('select sqlite_version(*)'))
end
def translate_exception(exception, message)
case exception.message
# SQLite 3.8.2 returns a newly formatted error message:
# UNIQUE constraint failed: *table_name*.*column_name*
# Older versions of SQLite return:
# column *column_name* is not unique
when /column(s)? .* (is|are) not unique/, /UNIQUE constraint failed: .*/
RecordNotUnique.new(message, exception)
else
super
end
end
private
COLLATE_REGEX = /.*\"(\w+)\".*collate\s+\"(\w+)\".*/i.freeze
def table_structure_with_collation(table_name, basic_structure)
collation_hash = {}
sql = "SELECT sql FROM
(SELECT * FROM sqlite_master UNION ALL
SELECT * FROM sqlite_temp_master)
WHERE type='table' and name='#{ table_name }' \;"
# Result will have following sample string
# CREATE TABLE "users" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
# "password_digest" varchar COLLATE "NOCASE");
result = exec_query(sql, 'SCHEMA').first
if result
# Splitting with left parantheses and picking up last will return all
# columns separated with comma(,).
columns_string = result["sql"].split('(').last
columns_string.split(',').each do |column_string|
# This regex will match the column name and collation type and will save
# the value in $1 and $2 respectively.
collation_hash[$1] = $2 if (COLLATE_REGEX =~ column_string)
end
basic_structure.map! do |column|
column_name = column['name']
if collation_hash.has_key? column_name
column['collation'] = collation_hash[column_name]
end
column
end
else
basic_structure.to_hash
end
end
end
end
end
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