Class Sequel::Database
In: lib/sequel/adapters/do.rb
lib/sequel/adapters/jdbc.rb
lib/sequel/database.rb
lib/sequel/database/schema_methods.rb
lib/sequel/database/schema_sql.rb
lib/sequel/extensions/query.rb
lib/sequel/extensions/schema_dumper.rb
Parent: Sequel::Database

A Database object represents a virtual connection to a database. The Database class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.

Methods

Included Modules

Metaprogramming

Constants

ADAPTERS = %w'ado amalgalite db2 dbi do firebird informix jdbc mysql odbc openbase oracle postgres sqlite'.collect{|x| x.to_sym}   Array of supported database adapters
SQL_BEGIN = 'BEGIN'.freeze
SQL_COMMIT = 'COMMIT'.freeze
SQL_RELEASE_SAVEPOINT = 'RELEASE SAVEPOINT autopoint_%d'.freeze
SQL_ROLLBACK = 'ROLLBACK'.freeze
SQL_ROLLBACK_TO_SAVEPOINT = 'ROLLBACK TO SAVEPOINT autopoint_%d'.freeze
SQL_SAVEPOINT = 'SAVEPOINT autopoint_%d'.freeze
TRANSACTION_BEGIN = 'Transaction.begin'.freeze
TRANSACTION_COMMIT = 'Transaction.commit'.freeze
TRANSACTION_ROLLBACK = 'Transaction.rollback'.freeze
POSTGRES_DEFAULT_RE = /\A(?:B?('.*')::[^']+|\((-?\d+(?:\.\d+)?)\))\z/
MSSQL_DEFAULT_RE = /\A(?:\(N?('.*')\)|\(\((-?\d+(?:\.\d+)?)\)\))\z/
MYSQL_TIMESTAMP_RE = /\ACURRENT_(?:DATE|TIMESTAMP)?\z/
STRING_DEFAULT_RE = /\A'(.*)'\z/
AUTOINCREMENT = 'AUTOINCREMENT'.freeze
CASCADE = 'CASCADE'.freeze
COMMA_SEPARATOR = ', '.freeze
NO_ACTION = 'NO ACTION'.freeze
NOT_NULL = ' NOT NULL'.freeze
NULL = ' NULL'.freeze
PRIMARY_KEY = ' PRIMARY KEY'.freeze
RESTRICT = 'RESTRICT'.freeze
SET_DEFAULT = 'SET DEFAULT'.freeze
SET_NULL = 'SET NULL'.freeze
TEMPORARY = 'TEMPORARY '.freeze
UNDERSCORE = '_'.freeze
UNIQUE = ' UNIQUE'.freeze
UNSIGNED = ' UNSIGNED'.freeze

Attributes

convert_types  [RW]  Whether to convert some Java types to ruby types when retrieving rows. True by default, can be set to false to roughly double performance when fetching rows.
database_type  [R]  The type of database we are connecting to
default_schema  [RW]  The default schema to use, generally should be nil.
loggers  [RW]  Array of SQL loggers to use for this database
opts  [R]  The options for this database
pool  [R]  The connection pool for this database
prepared_statements  [R]  The prepared statement objects for this database, keyed by name

Public Class methods

The Database subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.

[Source]

     # File lib/sequel/database.rb, line 105
105:     def self.adapter_class(scheme)
106:       scheme = scheme.to_s.gsub('-', '_').to_sym
107:       
108:       unless klass = ADAPTER_MAP[scheme]
109:         # attempt to load the adapter file
110:         begin
111:           Sequel.require "adapters/#{scheme}"
112:         rescue LoadError => e
113:           raise Sequel.convert_exception_class(e, AdapterNotFound)
114:         end
115:         
116:         # make sure we actually loaded the adapter
117:         unless klass = ADAPTER_MAP[scheme]
118:           raise AdapterNotFound, "Could not load #{scheme} adapter"
119:         end
120:       end
121:       klass
122:     end

Returns the scheme for the Database class.

[Source]

     # File lib/sequel/database.rb, line 125
125:     def self.adapter_scheme
126:       @scheme
127:     end

Connects to a database. See Sequel.connect.

[Source]

     # File lib/sequel/database.rb, line 130
130:     def self.connect(conn_string, opts = {}, &block)
131:       case conn_string
132:       when String
133:         if match = /\A(jdbc|do):/o.match(conn_string)
134:           c = adapter_class(match[1].to_sym)
135:           opts = {:uri=>conn_string}.merge(opts)
136:         else
137:           uri = URI.parse(conn_string)
138:           scheme = uri.scheme
139:           scheme = :dbi if scheme =~ /\Adbi-/
140:           c = adapter_class(scheme)
141:           uri_options = c.send(:uri_to_options, uri)
142:           uri.query.split('&').collect{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v} unless uri.query.to_s.strip.empty?
143:           uri_options.entries.each{|k,v| uri_options[k] = URI.unescape(v) if v.is_a?(String)}
144:           opts = uri_options.merge(opts)
145:         end
146:       when Hash
147:         opts = conn_string.merge(opts)
148:         c = adapter_class(opts[:adapter] || opts['adapter'])
149:       else
150:         raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}"
151:       end
152:       # process opts a bit
153:       opts = opts.inject({}) do |m, kv| k, v = *kv
154:         k = :user if k.to_s == 'username'
155:         m[k.to_sym] = v
156:         m
157:       end
158:       if block
159:         begin
160:           yield(db = c.new(opts))
161:         ensure
162:           db.disconnect if db
163:           ::Sequel::DATABASES.delete(db)
164:         end
165:         nil
166:       else
167:         c.new(opts)
168:       end
169:     end

The method to call on identifiers going into the database

[Source]

     # File lib/sequel/database.rb, line 172
172:     def self.identifier_input_method
173:       @@identifier_input_method
174:     end

Set the method to call on identifiers going into the database See Sequel.identifier_input_method=.

[Source]

     # File lib/sequel/database.rb, line 178
178:     def self.identifier_input_method=(v)
179:       @@identifier_input_method = v || ""
180:     end

The method to call on identifiers coming from the database

[Source]

     # File lib/sequel/database.rb, line 183
183:     def self.identifier_output_method
184:       @@identifier_output_method
185:     end

Set the method to call on identifiers coming from the database See Sequel.identifier_output_method=.

[Source]

     # File lib/sequel/database.rb, line 189
189:     def self.identifier_output_method=(v)
190:       @@identifier_output_method = v || ""
191:     end

Call the DATABASE_SETUP proc directly after initialization, so the object always uses sub adapter specific code. Also, raise an error immediately if the connection doesn‘t have a uri, since JDBC requires one.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 100
100:       def initialize(opts)
101:         @opts = opts
102:         @convert_types = opts.include?(:convert_types) ? typecast_value_boolean(opts[:convert_types]) : true
103:         raise(Error, "No connection string specified") unless uri
104:         if match = /\Ajdbc:([^:]+)/.match(uri) and prok = DATABASE_SETUP[match[1].to_sym]
105:           prok.call(self)
106:         end
107:         super(opts)
108:       end

Constructs a new instance of a database connection with the specified options hash.

Sequel::Database is an abstract class that is not useful by itself.

Takes the following options:

  • :default_schema : The default schema to use, should generally be nil
  • :disconnection_proc: A proc used to disconnect the connection.
  • :identifier_input_method: A string method symbol to call on identifiers going into the database
  • :identifier_output_method: A string method symbol to call on identifiers coming from the database
  • :loggers : An array of loggers to use.
  • :quote_identifiers : Whether to quote identifiers
  • :single_threaded : Whether to use a single-threaded connection pool

All options given are also passed to the ConnectionPool. If a block is given, it is used as the connection_proc for the ConnectionPool.

[Source]

    # File lib/sequel/database.rb, line 81
81:     def initialize(opts = {}, &block)
82:       @opts ||= opts
83:       
84:       @single_threaded = opts.include?(:single_threaded) ? typecast_value_boolean(opts[:single_threaded]) : @@single_threaded
85:       @schemas = {}
86:       @default_schema = opts.include?(:default_schema) ? opts[:default_schema] : default_schema_default
87:       @prepared_statements = {}
88:       @transactions = []
89:       @identifier_input_method = nil
90:       @identifier_output_method = nil
91:       @quote_identifiers = nil
92:       @pool = (@single_threaded ? SingleThreadedPool : ConnectionPool).new(connection_pool_default_options.merge(opts), &block)
93:       @pool.connection_proc = proc{|server| connect(server)} unless block
94:       @pool.disconnection_proc = proc{|conn| disconnect_connection(conn)} unless opts[:disconnection_proc]
95: 
96:       @loggers = Array(opts[:logger]) + Array(opts[:loggers])
97:       ::Sequel::DATABASES.push(self)
98:     end

Call the DATABASE_SETUP proc directly after initialization, so the object always uses sub adapter specific code. Also, raise an error immediately if the connection doesn‘t have a uri, since DataObjects requires one.

[Source]

    # File lib/sequel/adapters/do.rb, line 45
45:       def initialize(opts)
46:         @opts = opts
47:         raise(Error, "No connection string specified") unless uri
48:         if prok = DATABASE_SETUP[subadapter.to_sym]
49:           prok.call(self)
50:         end
51:         super(opts)
52:       end

Sets the default quote_identifiers mode for new databases. See Sequel.quote_identifiers=.

[Source]

     # File lib/sequel/database.rb, line 195
195:     def self.quote_identifiers=(value)
196:       @@quote_identifiers = value
197:     end

Sets the default single_threaded mode for new databases. See Sequel.single_threaded=.

[Source]

     # File lib/sequel/database.rb, line 201
201:     def self.single_threaded=(value)
202:       @@single_threaded = value
203:     end

Public Instance methods

Runs the supplied SQL statement string on the database server. Alias for run.

[Source]

     # File lib/sequel/database.rb, line 240
240:     def <<(sql)
241:       run(sql)
242:     end

Returns a dataset from the database. If the first argument is a string, the method acts as an alias for Database#fetch, returning a dataset for arbitrary SQL:

  DB['SELECT * FROM items WHERE name = ?', my_name].all

Otherwise, acts as an alias for Database#from, setting the primary table for the dataset:

  DB[:items].sql #=> "SELECT * FROM items"

[Source]

     # File lib/sequel/database.rb, line 254
254:     def [](*args)
255:       (String === args.first) ? fetch(*args) : from(*args)
256:     end

Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:

  DB.add_column :items, :name, :text, :unique => true, :null => false
  DB.add_column :items, :category, :text, :default => 'ruby'

See alter_table.

[Source]

    # File lib/sequel/database/schema_methods.rb, line 10
10:     def add_column(table, *args)
11:       alter_table(table) {add_column(*args)}
12:     end

Adds an index to a table for the given columns:

  DB.add_index :posts, :title
  DB.add_index :posts, [:author, :title], :unique => true

Options:

  • :ignore_errors - Ignore any DatabaseErrors that are raised

See alter_table.

[Source]

    # File lib/sequel/database/schema_methods.rb, line 24
24:     def add_index(table, columns, options={})
25:       e = options[:ignore_errors]
26:       begin
27:         alter_table(table){add_index(columns, options)}
28:       rescue DatabaseError
29:         raise unless e
30:       end
31:     end

Alters the given table with the specified block. Example:

  DB.alter_table :items do
    add_column :category, :text, :default => 'ruby'
    drop_column :category
    rename_column :cntr, :counter
    set_column_type :value, :float
    set_column_default :value, :float
    add_index [:group, :category]
    drop_index [:group, :category]
  end

Note that add_column accepts all the options available for column definitions using create_table, and add_index accepts all the options available for index definition.

See Schema::AlterTableGenerator.

[Source]

    # File lib/sequel/database/schema_methods.rb, line 50
50:     def alter_table(name, generator=nil, &block)
51:       remove_cached_schema(name)
52:       generator ||= Schema::AlterTableGenerator.new(self, &block)
53:       alter_table_sql_list(name, generator.operations).flatten.each {|sql| execute_ddl(sql)}
54:     end

Call the prepared statement with the given name with the given hash of arguments.

[Source]

     # File lib/sequel/database.rb, line 260
260:     def call(ps_name, hash={})
261:       prepared_statements[ps_name].call(hash)
262:     end

Execute the given stored procedure with the give name. If a block is given, the stored procedure should return rows.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 112
112:       def call_sproc(name, opts = {})
113:         args = opts[:args] || []
114:         sql = "{call #{name}(#{args.map{'?'}.join(',')})}"
115:         synchronize(opts[:server]) do |conn|
116:           cps = conn.prepareCall(sql)
117: 
118:           i = 0
119:           args.each{|arg| set_ps_arg(cps, arg, i+=1)}
120: 
121:           begin
122:             if block_given?
123:               yield cps.executeQuery
124:             else
125:               case opts[:type]
126:               when :insert
127:                 cps.executeUpdate
128:                 last_insert_id(conn, opts)
129:               else
130:                 cps.executeUpdate
131:               end
132:             end
133:           rescue NativeException, JavaSQL::SQLException => e
134:             raise_error(e)
135:           ensure
136:             cps.close
137:           end
138:         end
139:       end

Cast the given type to a literal type

[Source]

     # File lib/sequel/database.rb, line 265
265:     def cast_type_literal(type)
266:       type_literal(:type=>type)
267:     end

Connect to the database using JavaSQL::DriverManager.getConnection.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 142
142:       def connect(server)
143:         args = [uri(server_opts(server))]
144:         args.concat([opts[:user], opts[:password]]) if opts[:user] && opts[:password]
145:         setup_connection(JavaSQL::DriverManager.getConnection(*args))
146:       end

Setup a DataObjects::Connection to the database.

[Source]

    # File lib/sequel/adapters/do.rb, line 55
55:       def connect(server)
56:         setup_connection(::DataObjects::Connection.new(uri(server_opts(server))))
57:       end

Connects to the database. This method should be overridden by descendants.

[Source]

     # File lib/sequel/database.rb, line 270
270:     def connect
271:       raise NotImplementedError, "#connect should be overridden by adapters"
272:     end

Creates a view, replacing it if it already exists:

  DB.create_or_replace_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
  DB.create_or_replace_view(:ruby_items, DB[:items].filter(:category => 'ruby'))

[Source]

    # File lib/sequel/database/schema_methods.rb, line 92
92:     def create_or_replace_view(name, source)
93:       remove_cached_schema(name)
94:       source = source.sql if source.is_a?(Dataset)
95:       execute_ddl("CREATE OR REPLACE VIEW #{quote_schema_table(name)} AS #{source}")
96:     end

Creates a table with the columns given in the provided block:

  DB.create_table :posts do
    primary_key :id
    column :title, :text
    String :content
    index :title
  end

Options:

  • :temp - Create the table as a temporary table.
  • :ignore_index_errors - Ignore any errors when creating indexes.

See Schema::Generator.

[Source]

    # File lib/sequel/database/schema_methods.rb, line 70
70:     def create_table(name, options={}, &block)
71:       options = {:generator=>options} if options.is_a?(Schema::Generator)
72:       generator = options[:generator] || Schema::Generator.new(self, &block)
73:       create_table_from_generator(name, generator, options)
74:       create_table_indexes_from_generator(name, generator, options)
75:     end

Forcibly creates a table, attempting to drop it unconditionally (and catching any errors), then creating it.

[Source]

    # File lib/sequel/database/schema_methods.rb, line 78
78:     def create_table!(name, options={}, &block)
79:       drop_table(name) rescue nil
80:       create_table(name, options, &block)
81:     end

Creates the table unless the table already exists

[Source]

    # File lib/sequel/database/schema_methods.rb, line 84
84:     def create_table?(name, options={}, &block)
85:       create_table(name, options, &block) unless table_exists?(name)
86:     end

Creates a view based on a dataset or an SQL string:

  DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
  DB.create_view(:ruby_items, DB[:items].filter(:category => 'ruby'))

[Source]

     # File lib/sequel/database/schema_methods.rb, line 102
102:     def create_view(name, source)
103:       source = source.sql if source.is_a?(Dataset)
104:       execute_ddl("CREATE VIEW #{quote_schema_table(name)} AS #{source}")
105:     end

The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database objects that are using the same adapter are connecting to different database types (think JDBC or DataObjects).

[Source]

     # File lib/sequel/database.rb, line 281
281:     def database_type
282:       self.class.adapter_scheme
283:     end

Returns a blank dataset for this database

[Source]

     # File lib/sequel/database.rb, line 286
286:     def dataset
287:       ds = Sequel::Dataset.new(self)
288:     end

Return a Sequel::DataObjects::Dataset object for this database.

[Source]

    # File lib/sequel/adapters/do.rb, line 60
60:       def dataset(opts = nil)
61:         DataObjects::Dataset.new(self, opts)
62:       end

Return instances of JDBC::Dataset with the given opts.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 149
149:       def dataset(opts = nil)
150:         JDBC::Dataset.new(self, opts)
151:       end

Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected.

[Source]

     # File lib/sequel/database.rb, line 292
292:     def disconnect
293:       pool.disconnect
294:     end

Removes a column from the specified table:

  DB.drop_column :items, :category

See alter_table.

[Source]

     # File lib/sequel/database/schema_methods.rb, line 112
112:     def drop_column(table, *args)
113:       alter_table(table) {drop_column(*args)}
114:     end

Removes an index for the given table and column/s:

  DB.drop_index :posts, :title
  DB.drop_index :posts, [:author, :title]

See alter_table.

[Source]

     # File lib/sequel/database/schema_methods.rb, line 122
122:     def drop_index(table, columns, options={})
123:       alter_table(table){drop_index(columns, options)}
124:     end

Drops one or more tables corresponding to the given names:

  DB.drop_table(:posts, :comments)

[Source]

     # File lib/sequel/database/schema_methods.rb, line 129
129:     def drop_table(*names)
130:       names.each do |n|
131:         remove_cached_schema(n)
132:         execute_ddl(drop_table_sql(n))
133:       end
134:     end

Drops one or more views corresponding to the given names:

  DB.drop_view(:cheap_items)

[Source]

     # File lib/sequel/database/schema_methods.rb, line 139
139:     def drop_view(*names)
140:       names.each do |n|
141:         remove_cached_schema(n)
142:         execute_ddl("DROP VIEW #{quote_schema_table(n)}")
143:       end
144:     end

Dump indexes for all tables as a migration. This complements the :indexes=>false option to dump_schema_migration. Options:

  • :same_db - Create a dump for the same database type, so don‘t ignore errors if the index statements fail.

[Source]

    # File lib/sequel/extensions/schema_dumper.rb, line 13
13:     def dump_indexes_migration(options={})
14:       ts = tables
15:       "Class.new(Sequel::Migration) do\n  def up\n\#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_indexes(t, :add_index, options)}.reject{|x| x == ''}.join(\"\\n\\n\").gsub(/^/o, '    ')}\n  end\n  \n  def down\n\#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_indexes(t, :drop_index, options)}.reject{|x| x == ''}.join(\"\\n\\n\").gsub(/^/o, '    ')}\n  end\nend\n"
16:     end

Return a string that contains a Sequel::Migration subclass that when run would recreate the database structure. Options:

  • :same_db - Don‘t attempt to translate database types to ruby types. If this isn‘t set to true, all database types will be translated to ruby types, but there is no guarantee that the migration generated will yield the same type. Without this set, types that aren‘t recognized will be translated to a string-like type.
  • :indexes - If set to false, don‘t dump indexes (they can be added later via dump_index_migration).

[Source]

    # File lib/sequel/extensions/schema_dumper.rb, line 38
38:     def dump_schema_migration(options={})
39:       ts = tables
40:       "Class.new(Sequel::Migration) do\n  def up\n\#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_schema(t, options)}.join(\"\\n\\n\").gsub(/^/o, '    ')}\n  end\n  \n  def down\n    drop_table(\#{ts.sort_by{|t| t.to_s}.inspect[1...-1]})\n  end\nend\n"
41:     end

Return a string with a create table block that will recreate the given table‘s schema. Takes the same options as dump_schema_migration.

[Source]

    # File lib/sequel/extensions/schema_dumper.rb, line 56
56:     def dump_table_schema(table, options={})
57:       s = schema(table).dup
58:       pks = s.find_all{|x| x.last[:primary_key] == true}.map{|x| x.first}
59:       options = options.merge(:single_pk=>true) if pks.length == 1
60:       m = method(:column_schema_to_generator_opts)
61:       im = method(:index_to_generator_opts)
62:       indexes = indexes(table).sort_by{|k,v| k.to_s} if options[:indexes] != false and respond_to?(:indexes)
63:       gen = Schema::Generator.new(self) do
64:         s.each{|name, info| send(*m.call(name, info, options))}
65:         primary_key(pks) if !@primary_key && pks.length > 0
66:         indexes.each{|iname, iopts| send(:index, iopts[:columns], im.call(table, iname, iopts))} if indexes
67:       end
68:       commands = [gen.dump_columns, gen.dump_constraints, gen.dump_indexes].reject{|x| x == ''}.join("\n\n")
69:       "create_table(#{table.inspect}#{', :ignore_index_errors=>true' if !options[:same_db] && options[:indexes] != false && indexes && !indexes.empty?}) do\n#{commands.gsub(/^/o, '  ')}\nend"
70:     end

Executes the given SQL on the database. This method should be overridden in descendants. This method should not be called directly by user code.

[Source]

     # File lib/sequel/database.rb, line 298
298:     def execute(sql, opts={})
299:       raise NotImplementedError, "#execute should be overridden by adapters"
300:     end

Execute the given SQL. If a block is given, the DataObjects::Reader created is yielded to it. A block should not be provided unless a a SELECT statement is being used (or something else that returns rows). Otherwise, the return value is the insert id if opts[:type] is :insert, or the number of affected rows, otherwise.

[Source]

    # File lib/sequel/adapters/do.rb, line 69
69:       def execute(sql, opts={})
70:         log_info(sql)
71:         synchronize(opts[:server]) do |conn|
72:           begin
73:             command = conn.create_command(sql)
74:             res = block_given? ? command.execute_reader : command.execute_non_query
75:           rescue ::DataObjects::Error => e
76:             raise_error(e)
77:           end
78:           if block_given?
79:             begin
80:               yield(res)
81:             ensure
82:              res.close if res
83:             end
84:           elsif opts[:type] == :insert
85:             res.insert_id
86:           else
87:             res.affected_rows
88:           end
89:         end
90:       end

Execute the given SQL. If a block is given, if should be a SELECT statement or something else that returns rows.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 155
155:       def execute(sql, opts={}, &block)
156:         return call_sproc(sql, opts, &block) if opts[:sproc]
157:         return execute_prepared_statement(sql, opts, &block) if [Symbol, Dataset].any?{|c| sql.is_a?(c)}
158:         log_info(sql)
159:         synchronize(opts[:server]) do |conn|
160:           stmt = conn.createStatement
161:           begin
162:             if block_given?
163:               yield stmt.executeQuery(sql)
164:             else
165:               case opts[:type]
166:               when :ddl
167:                 stmt.execute(sql)
168:               when :insert
169:                 stmt.executeUpdate(sql)
170:                 last_insert_id(conn, opts.merge(:stmt=>stmt))
171:               else
172:                 stmt.executeUpdate(sql)
173:               end
174:             end
175:           rescue NativeException, JavaSQL::SQLException => e
176:             raise_error(e)
177:           ensure
178:             stmt.close
179:           end
180:         end
181:       end

Method that should be used when submitting any DDL (Data Definition Language) SQL. By default, calls execute_dui. This method should not be called directly by user code.

[Source]

     # File lib/sequel/database.rb, line 305
305:     def execute_ddl(sql, opts={}, &block)
306:       execute_dui(sql, opts, &block)
307:     end

Execute the given DDL SQL, which should not return any values or rows.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 186
186:       def execute_ddl(sql, opts={})
187:         execute(sql, {:type=>:ddl}.merge(opts))
188:       end

Execute the SQL on the this database, returning the number of affected rows.

[Source]

    # File lib/sequel/adapters/do.rb, line 94
94:       def execute_dui(sql, opts={})
95:         execute(sql, opts)
96:       end
execute_dui(sql, opts={})

Alias for execute

Method that should be used when issuing a DELETE, UPDATE, or INSERT statement. By default, calls execute. This method should not be called directly by user code.

[Source]

     # File lib/sequel/database.rb, line 312
312:     def execute_dui(sql, opts={}, &block)
313:       execute(sql, opts, &block)
314:     end

Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.

[Source]

     # File lib/sequel/database.rb, line 319
319:     def execute_insert(sql, opts={}, &block)
320:       execute_dui(sql, opts, &block)
321:     end

Execute the SQL on this database, returning the primary key of the table being inserted to.

[Source]

     # File lib/sequel/adapters/do.rb, line 100
100:       def execute_insert(sql, opts={})
101:         execute(sql, opts.merge(:type=>:insert))
102:       end

Execute the given INSERT SQL, returning the last inserted row id.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 192
192:       def execute_insert(sql, opts={})
193:         execute(sql, {:type=>:insert}.merge(opts))
194:       end

Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:

  DB.fetch('SELECT * FROM items'){|r| p r}

The method returns a dataset instance:

  DB.fetch('SELECT * FROM items').all

Fetch can also perform parameterized queries for protection against SQL injection:

  DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all

[Source]

     # File lib/sequel/database.rb, line 336
336:     def fetch(sql, *args, &block)
337:       ds = dataset.with_sql(sql, *args)
338:       ds.each(&block) if block
339:       ds
340:     end

Returns a new dataset with the from method invoked. If a block is given, it is used as a filter on the dataset.

[Source]

     # File lib/sequel/database.rb, line 344
344:     def from(*args, &block)
345:       ds = dataset.from(*args)
346:       block ? ds.filter(&block) : ds
347:     end

Returns a single value from the database, e.g.:

  # SELECT 1
  DB.get(1) #=> 1

  # SELECT version()
  DB.get(:version.sql_function) #=> ...

[Source]

     # File lib/sequel/database.rb, line 356
356:     def get(*args, &block)
357:       dataset.get(*args, &block)
358:     end

The method to call on identifiers going into the database

[Source]

     # File lib/sequel/database.rb, line 361
361:     def identifier_input_method
362:       case @identifier_input_method
363:       when nil
364:         @identifier_input_method = @opts.include?(:identifier_input_method) ? @opts[:identifier_input_method] : (@@identifier_input_method.nil? ? identifier_input_method_default : @@identifier_input_method)
365:         @identifier_input_method == "" ? nil : @identifier_input_method
366:       when ""
367:         nil
368:       else
369:         @identifier_input_method
370:       end
371:     end

Set the method to call on identifiers going into the database

[Source]

     # File lib/sequel/database.rb, line 374
374:     def identifier_input_method=(v)
375:       reset_schema_utility_dataset
376:       @identifier_input_method = v || ""
377:     end

The method to call on identifiers coming from the database

[Source]

     # File lib/sequel/database.rb, line 380
380:     def identifier_output_method
381:       case @identifier_output_method
382:       when nil
383:         @identifier_output_method = @opts.include?(:identifier_output_method) ? @opts[:identifier_output_method] : (@@identifier_output_method.nil? ? identifier_output_method_default : @@identifier_output_method)
384:         @identifier_output_method == "" ? nil : @identifier_output_method
385:       when ""
386:         nil
387:       else
388:         @identifier_output_method
389:       end
390:     end

Set the method to call on identifiers coming from the database

[Source]

     # File lib/sequel/database.rb, line 393
393:     def identifier_output_method=(v)
394:       reset_schema_utility_dataset
395:       @identifier_output_method = v || ""
396:     end

Return a hash containing index information. Hash keys are index name symbols. Values are subhashes with two keys, :columns and :unique. The value of :columns is an array of symbols of column names. The value of :unique is true or false depending on if the index is unique.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 200
200:       def indexes(table, opts={})
201:         m = output_identifier_meth
202:         im = input_identifier_meth
203:         schema, table = schema_and_table(table)
204:         schema ||= opts[:schema]
205:         schema = im.call(schema) if schema
206:         table = im.call(table)
207:         indexes = {}
208:         metadata(:getIndexInfo, nil, schema, table, false, true) do |r|
209:           next unless name = r[:column_name]
210:           next if respond_to?(:primary_key_index_re, true) and r[:index_name] =~ primary_key_index_re 
211:           i = indexes[m.call(r[:index_name])] ||= {:columns=>[], :unique=>[false, 0].include?(r[:non_unique])}
212:           i[:columns] << m.call(name)
213:         end
214:         indexes
215:       end

Returns a string representation of the database object including the class name and the connection URI (or the opts if the URI cannot be constructed).

[Source]

     # File lib/sequel/database.rb, line 401
401:     def inspect
402:       "#<#{self.class}: #{(uri rescue opts).inspect}>" 
403:     end

Proxy the literal call to the dataset, used for default values.

[Source]

     # File lib/sequel/database.rb, line 406
406:     def literal(v)
407:       schema_utility_dataset.literal(v)
408:     end

Log a message at level info to all loggers. All SQL logging goes through this method.

[Source]

     # File lib/sequel/database.rb, line 412
412:     def log_info(message, args=nil)
413:       message = "#{message}; #{args.inspect}" if args
414:       @loggers.each{|logger| logger.info(message)}
415:     end

Remove any existing loggers and just use the given logger.

[Source]

     # File lib/sequel/database.rb, line 418
418:     def logger=(logger)
419:       @loggers = Array(logger)
420:     end

Return a dataset modified by the query block

[Source]

    # File lib/sequel/extensions/query.rb, line 8
 8:     def query(&block)
 9:       dataset.query(&block)
10:     end

Whether to quote identifiers (columns and tables) for this database

[Source]

     # File lib/sequel/database.rb, line 423
423:     def quote_identifiers=(v)
424:       reset_schema_utility_dataset
425:       @quote_identifiers = v
426:     end

Returns true if the database quotes identifiers.

[Source]

     # File lib/sequel/database.rb, line 429
429:     def quote_identifiers?
430:       return @quote_identifiers unless @quote_identifiers.nil?
431:       @quote_identifiers = @opts.include?(:quote_identifiers) ? @opts[:quote_identifiers] : (@@quote_identifiers.nil? ? quote_identifiers_default : @@quote_identifiers)
432:     end

Renames a column in the specified table. This method expects the current column name and the new column name:

  DB.rename_column :items, :cntr, :counter

See alter_table.

[Source]

     # File lib/sequel/database/schema_methods.rb, line 162
162:     def rename_column(table, *args)
163:       alter_table(table) {rename_column(*args)}
164:     end

Renames a table:

  DB.tables #=> [:items]
  DB.rename_table :items, :old_items
  DB.tables #=> [:old_items]

[Source]

     # File lib/sequel/database/schema_methods.rb, line 151
151:     def rename_table(name, new_name)
152:       remove_cached_schema(name)
153:       execute_ddl(rename_table_sql(name, new_name))
154:     end

Runs the supplied SQL statement string on the database server. Returns nil. Options:

  • :server - The server to run the SQL on.

[Source]

     # File lib/sequel/database.rb, line 437
437:     def run(sql, opts={})
438:       execute_ddl(sql, opts)
439:       nil
440:     end

Parse the schema from the database. Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. Available options are:

  • :reload - Get fresh information from the database, instead of using cached information. If table_name is blank, :reload should be used unless you are sure that schema has not been called before with a table_name, otherwise you may only getting the schemas for tables that have been requested explicitly.
  • :schema - An explicit schema to use. It may also be implicitly provided via the table name.

[Source]

     # File lib/sequel/database.rb, line 459
459:     def schema(table, opts={})
460:       raise(Error, 'schema parsing is not implemented on this database') unless respond_to?(:schema_parse_table, true)
461: 
462:       sch, table_name = schema_and_table(table)
463:       quoted_name = quote_schema_table(table)
464:       opts = opts.merge(:schema=>sch) if sch && !opts.include?(:schema)
465: 
466:       @schemas.delete(quoted_name) if opts[:reload]
467:       return @schemas[quoted_name] if @schemas[quoted_name]
468: 
469:       cols = schema_parse_table(table_name, opts)
470:       raise(Error, 'schema parsing returned no columns, table probably doesn\'t exist') if cols.nil? || cols.empty?
471:       cols.each{|_,c| c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type])}
472:       @schemas[quoted_name] = cols
473:     end

Returns a new dataset with the select method invoked.

[Source]

     # File lib/sequel/database.rb, line 443
443:     def select(*args, &block)
444:       dataset.select(*args, &block)
445:     end

Default serial primary key options.

[Source]

    # File lib/sequel/database/schema_sql.rb, line 19
19:     def serial_primary_key_options
20:       {:primary_key => true, :type => Integer, :auto_increment => true}
21:     end

Sets the default value for the given column in the given table:

  DB.set_column_default :items, :category, 'perl!'

See alter_table.

[Source]

     # File lib/sequel/database/schema_methods.rb, line 171
171:     def set_column_default(table, *args)
172:       alter_table(table) {set_column_default(*args)}
173:     end

Set the data type for the given column in the given table:

  DB.set_column_type :items, :price, :float

See alter_table.

[Source]

     # File lib/sequel/database/schema_methods.rb, line 180
180:     def set_column_type(table, *args)
181:       alter_table(table) {set_column_type(*args)}
182:     end

Returns true if the database is using a single-threaded connection pool.

[Source]

     # File lib/sequel/database.rb, line 476
476:     def single_threaded?
477:       @single_threaded
478:     end

Return the subadapter type for this database, i.e. sqlite3 for do:sqlite3::memory:.

[Source]

     # File lib/sequel/adapters/do.rb, line 106
106:       def subadapter
107:         uri.split(":").first
108:       end

Whether the database and adapter support savepoints, false by default

[Source]

     # File lib/sequel/database.rb, line 486
486:     def supports_savepoints?
487:       false
488:     end

Acquires a database connection, yielding it to the passed block.

[Source]

     # File lib/sequel/database.rb, line 481
481:     def synchronize(server=nil, &block)
482:       @pool.hold(server || :default, &block)
483:     end

Returns true if a table with the given name exists. This requires a query to the database unless this database object already has the schema for the given table name.

[Source]

     # File lib/sequel/database.rb, line 493
493:     def table_exists?(name)
494:       begin 
495:         from(name).first
496:         true
497:       rescue
498:         false
499:       end
500:     end

All tables in this database

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 218
218:       def tables
219:         ts = []
220:         m = output_identifier_meth
221:         metadata(:getTables, nil, nil, nil, ['TABLE'].to_java(:string)){|h| ts << m.call(h[:table_name])}
222:         ts
223:       end

Attempts to acquire a database connection. Returns true if successful. Will probably raise an error if unsuccessful.

[Source]

     # File lib/sequel/database.rb, line 504
504:     def test_connection(server=nil)
505:       synchronize(server){|conn|}
506:       true
507:     end

Starts a database transaction. When a database transaction is used, either all statements are successful or none of the statements are successful. Note that MySQL MyISAM tabels do not support transactions.

The following options are respected:

  • :server - The server to use for the transaction
  • :savepoint - Whether to create a new savepoint for this transaction, only respected if the database adapter supports savepoints. By default Sequel will reuse an existing transaction, so if you want to use a savepoint you must use this option.

[Source]

     # File lib/sequel/database.rb, line 520
520:     def transaction(opts={}, &block)
521:       synchronize(opts[:server]) do |conn|
522:         return yield(conn) if already_in_transaction?(conn, opts)
523:         _transaction(conn, &block)
524:       end
525:     end

Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.

[Source]

     # File lib/sequel/database.rb, line 532
532:     def typecast_value(column_type, value)
533:       return nil if value.nil?
534:       meth = "typecast_value_#{column_type}"
535:       begin
536:         respond_to?(meth, true) ? send(meth, value) : value
537:       rescue ArgumentError, TypeError => e
538:         raise Sequel.convert_exception_class(e, InvalidValue)
539:       end
540:     end

Returns the URI identifying the database. This method can raise an error if the database used options instead of a connection string.

[Source]

     # File lib/sequel/database.rb, line 545
545:     def uri
546:       uri = URI::Generic.new(
547:         self.class.adapter_scheme.to_s,
548:         nil,
549:         @opts[:host],
550:         @opts[:port],
551:         nil,
552:         "/#{@opts[:database]}",
553:         nil,
554:         nil,
555:         nil
556:       )
557:       uri.user = @opts[:user]
558:       uri.password = @opts[:password] if uri.user
559:       uri.to_s
560:     end

The uri for this connection. You can specify the uri using the :uri, :url, or :database options. You don‘t need to worry about this if you use Sequel.connect with the JDBC connectrion strings.

[Source]

     # File lib/sequel/adapters/jdbc.rb, line 229
229:       def uri(opts={})
230:         opts = @opts.merge(opts)
231:         ur = opts[:uri] || opts[:url] || opts[:database]
232:         ur =~ /^\Ajdbc:/ ? ur : "jdbc:#{ur}"
233:       end

Return the DataObjects URI for the Sequel URI, removing the do: prefix.

[Source]

     # File lib/sequel/adapters/do.rb, line 112
112:       def uri(opts={})
113:         opts = @opts.merge(opts)
114:         (opts[:uri] || opts[:url]).sub(/\Ado:/, '')
115:       end

Explicit alias of uri for easier subclassing.

[Source]

     # File lib/sequel/database.rb, line 563
563:     def url
564:       uri
565:     end

[Validate]