Module: Sequel::SQLite::DatabaseMethods

Overview

No matter how you connect to SQLite, the following Database options can be used to set PRAGMAs on connections in a thread-safe manner: :auto_vacuum, :foreign_keys, :synchronous, and :temp_store.

Constant Summary collapse

AUTO_VACUUM =
[:none, :full, :incremental].freeze
PRIMARY_KEY_INDEX_RE =
/\Asqlite_autoindex_/.freeze
SYNCHRONOUS =
[:off, :normal, :full].freeze
TABLES_FILTER =
"type = 'table' AND NOT name = 'sqlite_sequence'".freeze
TEMP_STORE =
[:default, :file, :memory].freeze
VIEWS_FILTER =
"type = 'view'".freeze
TRANSACTION_MODE =
{
  :deferred => "BEGIN DEFERRED TRANSACTION".freeze,
  :immediate => "BEGIN IMMEDIATE TRANSACTION".freeze,
  :exclusive => "BEGIN EXCLUSIVE TRANSACTION".freeze,
  nil => Sequel::Database::SQL_BEGIN,
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Database::ResetIdentifierMangling

extended

Instance Attribute Details

#integer_booleansObject

Whether to use integers for booleans in the database. SQLite recommends booleans be stored as integers, but historically Sequel has used ‘t’/‘f’.



26
27
28
# File 'lib/sequel/adapters/shared/sqlite.rb', line 26

def integer_booleans
  @integer_booleans
end

#transaction_modeObject

A symbol signifying the value of the default transaction mode



49
50
51
# File 'lib/sequel/adapters/shared/sqlite.rb', line 49

def transaction_mode
  @transaction_mode
end

#use_timestamp_timezones=(value) ⇒ Object (writeonly)

Override the default setting for whether to use timezones in timestamps. For backwards compatibility, it is set to true by default. Anyone wanting to use SQLite’s datetime functions should set it to false using this method. It’s possible that the default will change in a future version, so anyone relying on timezones in timestamps should set this to true.



167
168
169
# File 'lib/sequel/adapters/shared/sqlite.rb', line 167

def use_timestamp_timezones=(value)
  @use_timestamp_timezones = value
end

Instance Method Details

#auto_vacuumObject

A symbol signifying the value of the auto_vacuum PRAGMA.



29
30
31
# File 'lib/sequel/adapters/shared/sqlite.rb', line 29

def auto_vacuum
  AUTO_VACUUM[pragma_get(:auto_vacuum).to_i]
end

#auto_vacuum=(value) ⇒ Object

Set the auto_vacuum PRAGMA using the given symbol (:none, :full, or :incremental). See pragma_set. Consider using the :auto_vacuum Database option instead.



36
37
38
39
# File 'lib/sequel/adapters/shared/sqlite.rb', line 36

def auto_vacuum=(value)
  value = AUTO_VACUUM.index(value) || (raise Error, "Invalid value for auto_vacuum option. Please specify one of :none, :full, :incremental.")
  pragma_set(:auto_vacuum, value)
end

#case_sensitive_like=(value) ⇒ Object

Set the case_sensitive_like PRAGMA using the given boolean value, if using SQLite 3.2.3+. If not using 3.2.3+, no error is raised. See pragma_set. Consider using the :case_sensitive_like Database option instead.



44
45
46
# File 'lib/sequel/adapters/shared/sqlite.rb', line 44

def case_sensitive_like=(value)
  pragma_set(:case_sensitive_like, !!value ? 'on' : 'off') if sqlite_version >= 30203
end

#database_typeObject

SQLite uses the :sqlite database type.



61
62
63
# File 'lib/sequel/adapters/shared/sqlite.rb', line 61

def database_type
  :sqlite
end

#foreign_key_list(table, opts = OPTS) ⇒ Object

Return the array of foreign key info hashes using the foreign_key_list PRAGMA, including information for the :on_update and :on_delete entries.



80
81
82
83
84
85
86
87
88
89
90
91
92
# File 'lib/sequel/adapters/shared/sqlite.rb', line 80

def foreign_key_list(table, opts=OPTS)
  m = output_identifier_meth
  h = {}
  .with_sql("PRAGMA foreign_key_list(?)", input_identifier_meth.call(table)).each do |row|
    if r = h[row[:id]]
      r[:columns] << m.call(row[:from])
      r[:key] << m.call(row[:to]) if r[:key]
    else
      h[row[:id]] = {:columns=>[m.call(row[:from])], :table=>m.call(row[:table]), :key=>([m.call(row[:to])] if row[:to]), :on_update=>on_delete_sql_to_sym(row[:on_update]), :on_delete=>on_delete_sql_to_sym(row[:on_delete])}
    end
  end
  h.values
end

#foreign_keysObject

Boolean signifying the value of the foreign_keys PRAGMA, or nil if not using SQLite 3.6.19+.



67
68
69
# File 'lib/sequel/adapters/shared/sqlite.rb', line 67

def foreign_keys
  pragma_get(:foreign_keys).to_i == 1 if sqlite_version >= 30619
end

#foreign_keys=(value) ⇒ Object

Set the foreign_keys PRAGMA using the given boolean value, if using SQLite 3.6.19+. If not using 3.6.19+, no error is raised. See pragma_set. Consider using the :foreign_keys Database option instead.



74
75
76
# File 'lib/sequel/adapters/shared/sqlite.rb', line 74

def foreign_keys=(value)
  pragma_set(:foreign_keys, !!value ? 'on' : 'off') if sqlite_version >= 30619
end

#indexes(table, opts = OPTS) ⇒ Object

Use the index_list and index_info PRAGMAs to determine the indexes on the table.



95
96
97
98
99
100
101
102
103
104
105
106
107
108
# File 'lib/sequel/adapters/shared/sqlite.rb', line 95

def indexes(table, opts=OPTS)
  m = output_identifier_meth
  im = input_identifier_meth
  indexes = {}
  .with_sql("PRAGMA index_list(?)", im.call(table)).each do |r|
    # :only_autocreated internal option can be used to get only autocreated indexes
    next if (!!(r[:name] =~ PRIMARY_KEY_INDEX_RE) ^ !!opts[:only_autocreated])
    indexes[m.call(r[:name])] = {:unique=>r[:unique].to_i==1}
  end
  indexes.each do |k, v|
    v[:columns] = .with_sql("PRAGMA index_info(?)", im.call(k)).map(:name).map{|x| m.call(x)}
  end
  indexes
end

#pragma_get(name) ⇒ Object

Get the value of the given PRAGMA.



111
112
113
# File 'lib/sequel/adapters/shared/sqlite.rb', line 111

def pragma_get(name)
  self["PRAGMA #{name}"].single_value
end

#pragma_set(name, value) ⇒ Object

Set the value of the given PRAGMA to value.

This method is not thread safe, and will not work correctly if there are multiple connections in the Database’s connection pool. PRAGMA modifications should be done when the connection is created, using an option provided when creating the Database object.



121
122
123
# File 'lib/sequel/adapters/shared/sqlite.rb', line 121

def pragma_set(name, value)
  execute_ddl("PRAGMA #{name} = #{value}")
end

#set_integer_booleansObject

Set the integer_booleans option using the passed in :integer_boolean option.



126
127
128
# File 'lib/sequel/adapters/shared/sqlite.rb', line 126

def set_integer_booleans
  @integer_booleans = @opts.has_key?(:integer_booleans) ? typecast_value_boolean(@opts[:integer_booleans]) : true
end

#sqlite_versionObject

The version of the server as an integer, where 3.6.19 = 30619. If the server version can’t be determined, 0 is used.



132
133
134
135
136
137
138
139
140
# File 'lib/sequel/adapters/shared/sqlite.rb', line 132

def sqlite_version
  return @sqlite_version if defined?(@sqlite_version)
  @sqlite_version = begin
    v = fetch('SELECT sqlite_version()').single_value
    [10000, 100, 1].zip(v.split('.')).inject(0){|a, m| a + m[0] * Integer(m[1])}
  rescue
    0
  end
end

#supports_create_table_if_not_exists?Boolean

SQLite supports CREATE TABLE IF NOT EXISTS syntax since 3.3.0.

Returns:

  • (Boolean)


143
144
145
# File 'lib/sequel/adapters/shared/sqlite.rb', line 143

def supports_create_table_if_not_exists?
  sqlite_version >= 30300
end

#supports_deferrable_foreign_key_constraints?Boolean

SQLite 3.6.19+ supports deferrable foreign key constraints.

Returns:

  • (Boolean)


148
149
150
# File 'lib/sequel/adapters/shared/sqlite.rb', line 148

def supports_deferrable_foreign_key_constraints?
  sqlite_version >= 30619
end

#supports_partial_indexes?Boolean

SQLite 3.8.0+ supports partial indexes.

Returns:

  • (Boolean)


153
154
155
# File 'lib/sequel/adapters/shared/sqlite.rb', line 153

def supports_partial_indexes?
  sqlite_version >= 30800
end

#supports_savepoints?Boolean

SQLite 3.6.8+ supports savepoints.

Returns:

  • (Boolean)


158
159
160
# File 'lib/sequel/adapters/shared/sqlite.rb', line 158

def supports_savepoints?
  sqlite_version >= 30608
end

#synchronousObject

A symbol signifying the value of the synchronous PRAGMA.



176
177
178
# File 'lib/sequel/adapters/shared/sqlite.rb', line 176

def synchronous
  SYNCHRONOUS[pragma_get(:synchronous).to_i]
end

#synchronous=(value) ⇒ Object

Set the synchronous PRAGMA using the given symbol (:off, :normal, or :full). See pragma_set. Consider using the :synchronous Database option instead.



182
183
184
185
# File 'lib/sequel/adapters/shared/sqlite.rb', line 182

def synchronous=(value)
  value = SYNCHRONOUS.index(value) || (raise Error, "Invalid value for synchronous option. Please specify one of :off, :normal, :full.")
  pragma_set(:synchronous, value)
end

#tables(opts = OPTS) ⇒ Object

Array of symbols specifying the table names in the current database.

Options:

:server

Set the server to use.



191
192
193
# File 'lib/sequel/adapters/shared/sqlite.rb', line 191

def tables(opts=OPTS)
  tables_and_views(TABLES_FILTER, opts)
end

#temp_storeObject

A symbol signifying the value of the temp_store PRAGMA.



196
197
198
# File 'lib/sequel/adapters/shared/sqlite.rb', line 196

def temp_store
  TEMP_STORE[pragma_get(:temp_store).to_i]
end

#temp_store=(value) ⇒ Object

Set the temp_store PRAGMA using the given symbol (:default, :file, or :memory). See pragma_set. Consider using the :temp_store Database option instead.



202
203
204
205
# File 'lib/sequel/adapters/shared/sqlite.rb', line 202

def temp_store=(value)
  value = TEMP_STORE.index(value) || (raise Error, "Invalid value for temp_store option. Please specify one of :default, :file, :memory.")
  pragma_set(:temp_store, value)
end

#use_timestamp_timezones?Boolean

SQLite supports timezones in timestamps, since it just stores them as strings, but it breaks the usage of SQLite’s datetime functions.

Returns:

  • (Boolean)


171
172
173
# File 'lib/sequel/adapters/shared/sqlite.rb', line 171

def use_timestamp_timezones?
  defined?(@use_timestamp_timezones) ? @use_timestamp_timezones : (@use_timestamp_timezones = false)
end

#views(opts = OPTS) ⇒ Object

Array of symbols specifying the view names in the current database.

Options:

:server

Set the server to use.



211
212
213
# File 'lib/sequel/adapters/shared/sqlite.rb', line 211

def views(opts=OPTS)
  tables_and_views(VIEWS_FILTER, opts)
end