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.
This methods generally execute SQL code on the database server.
The default transaction isolation level for this database, used for all future transactions. For MSSQL, this should be set to something if you ever plan to use the :isolation option to Database#transaction, as on MSSQL if affects all future transactions on the same connection.
Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:
DB << "UPADTE albums SET artist_id = NULL" << "DROP TABLE artists"
# File lib/sequel/database/query.rb, line 43 def <<(sql) run(sql) self end
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].filter(:id=>1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb, line 53 def call(ps_name, hash={}) prepared_statements[ps_name].call(hash) 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.
# File lib/sequel/database/query.rb, line 59 def execute(sql, opts={}) raise NotImplemented, "#execute should be overridden by adapters" end
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb, line 66 def execute_ddl(sql, opts={}, &block) execute_dui(sql, opts, &block) end
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.
# File lib/sequel/database/query.rb, line 73 def execute_dui(sql, opts={}, &block) execute(sql, opts, &block) 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.
# File lib/sequel/database/query.rb, line 80 def execute_insert(sql, opts={}, &block) execute_dui(sql, opts, &block) end
Returns a single value from the database, e.g.:
DB.get(1) # SELECT 1 # => 1 DB.get{server_version{}} # SELECT server_version()
# File lib/sequel/database/query.rb, line 89 def get(*args, &block) dataset.get(*args, &block) end
Return a hash containing index information for the table. 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.
Should not include the primary key index, functional indexes, or partial indexes.
DB.indexes(:artists) # => {:artists_name_ukey=>{:columns=>[:name], :unique=>true}}
# File lib/sequel/database/query.rb, line 102 def indexes(table, opts={}) raise NotImplemented, "#indexes should be overridden by adapters" end
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. The table argument can also be a dataset, as long as it only has one table. Available options are:
:reload |
Ignore any cached results, and get fresh information from the database. |
:schema |
An explicit schema to use. It may also be implicitly provided via the table name. |
If schema parsing is supported by the database, the column information should hash at least contain the following entries:
:allow_null |
Whether NULL is an allowed value for the column. |
:db_type |
The database type for the column, as a database specific string. |
:default |
The database default for the column, as a database specific string. |
:primary_key |
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key. |
:ruby_default |
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value. |
:type |
A symbol specifying the type, such as :integer or :string. |
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb, line 156 def schema(table, opts={}) raise(Error, 'schema parsing is not implemented on this database') unless respond_to?(:schema_parse_table, true) opts = opts.dup if table.is_a?(Dataset) o = table.opts from = o[:from] raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) tab = table.first_source_table sch, table_name = schema_and_table(tab) quoted_name = table.literal(tab) opts[:dataset] = table else sch, table_name = schema_and_table(table) quoted_name = quote_schema_table(table) end opts[:schema] = sch if sch && !opts.include?(:schema) @schemas.delete(quoted_name) if opts[:reload] return @schemas[quoted_name] if @schemas[quoted_name] cols = schema_parse_table(table_name, opts) raise(Error, 'schema parsing returned no columns, table probably doesn\t exist') if cols.nil? || cols.empty? cols.each{|_,c| c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type])} @schemas[quoted_name] = cols end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don't have permission to SELECT from the table.
# File lib/sequel/database/query.rb, line 191 def table_exists?(name) sch, table_name = schema_and_table(name) name = SQL::QualifiedIdentifier.new(sch, table_name) if sch _table_exists?(from(name)) true rescue DatabaseError false end
Return all tables in the database as an array of symbols.
DB.tables # => [:albums, :artists]
# File lib/sequel/database/query.rb, line 203 def tables(opts={}) raise NotImplemented, "#tables should be overridden by adapters" 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:
:isolation |
The transaction isolation level to use for this transaction, should be :uncommitted, :committed, :repeatable, or :serializable, used if given and the database/adapter supports customizable transaction isolation levels. |
:prepare |
A string to use as the transaction identifier for a prepared transaction (two-phase commit), if the database/adapter supports prepared transactions. |
:rollback |
Can the set to :reraise to reraise any Sequel::Rollback exceptions raised, or :always to always rollback even if no exceptions occur (useful for testing). |
: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. |
# File lib/sequel/database/query.rb, line 228 def transaction(opts={}, &block) synchronize(opts[:server]) do |conn| return yield(conn) if already_in_transaction?(conn, opts) _transaction(conn, opts, &block) end end
These methods execute code on the database that modifies the database's schema.
The order of column modifiers to use when defining a column.
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.
# File lib/sequel/database/schema_methods.rb, line 33 def add_column(table, *args) alter_table(table) {add_column(*args)} 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.
# File lib/sequel/database/schema_methods.rb, line 46 def add_index(table, columns, options={}) e = options[:ignore_errors] begin alter_table(table){add_index(columns, options)} rescue DatabaseError raise unless e end 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 and the "Migrations and Schema Modification" guide.
# File lib/sequel/database/schema_methods.rb, line 72 def alter_table(name, generator=nil, &block) generator ||= Schema::AlterTableGenerator.new(self, &block) remove_cached_schema(name) apply_alter_table(name, generator.operations) nil 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'))
# File lib/sequel/database/schema_methods.rb, line 130 def create_or_replace_view(name, source) source = source.sql if source.is_a?(Dataset) execute_ddl("CREATE OR REPLACE VIEW #{quote_schema_table(name)} AS #{source}") remove_cached_schema(name) nil 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 and the "Migrations and Schema Modification" guide.
# File lib/sequel/database/schema_methods.rb, line 93 def create_table(name, options={}, &block) remove_cached_schema(name) options = {:generator=>options} if options.is_a?(Schema::Generator) generator = options[:generator] || Schema::Generator.new(self, &block) create_table_from_generator(name, generator, options) create_table_indexes_from_generator(name, generator, options) nil end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT * FROM a LIMIT a -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb, line 108 def create_table!(name, options={}, &block) drop_table(name) if table_exists?(name) create_table(name, options, &block) end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT * FROM a LIMIT a -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb, line 118 def create_table?(name, options={}, &block) if supports_create_table_if_not_exists? create_table(name, options.merge(:if_not_exists=>true), &block) elsif !table_exists?(name) create_table(name, options, &block) end 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'))
# File lib/sequel/database/schema_methods.rb, line 141 def create_view(name, source) source = source.sql if source.is_a?(Dataset) execute_ddl("CREATE VIEW #{quote_schema_table(name)} AS #{source}") end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 151 def drop_column(table, *args) alter_table(table) {drop_column(*args)} 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.
# File lib/sequel/database/schema_methods.rb, line 161 def drop_index(table, columns, options={}) alter_table(table){drop_index(columns, options)} end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, :cascade=>true)
# File lib/sequel/database/schema_methods.rb, line 170 def drop_table(*names) options = names.last.is_a?(Hash) ? names.pop : {} names.each do |n| execute_ddl(drop_table_sql(n, options)) remove_cached_schema(n) end nil end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, :cascade=>true)
# File lib/sequel/database/schema_methods.rb, line 184 def drop_view(*names) options = names.last.is_a?(Hash) ? names.pop : {} names.each do |n| execute_ddl(drop_view_sql(n, options)) remove_cached_schema(n) end nil 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.
# File lib/sequel/database/schema_methods.rb, line 210 def rename_column(table, *args) alter_table(table) {rename_column(*args)} end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb, line 198 def rename_table(name, new_name) execute_ddl(rename_table_sql(name, new_name)) remove_cached_schema(name) nil end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 219 def set_column_default(table, *args) alter_table(table) {set_column_default(*args)} end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 228 def set_column_type(table, *args) alter_table(table) {set_column_type(*args)} end
These methods all return instances of this database's dataset class.
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all 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"
# File lib/sequel/database/dataset.rb, line 19 def [](*args) (String === args.first) ? fetch(*args) : from(*args) end
Returns a blank dataset for this database.
DB.dataset # SELECT * DB.dataset.from(:items) # SELECT * FROM items
# File lib/sequel/database/dataset.rb, line 27 def dataset(opts=nil) @dataset_class.new(self, opts) 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 fetch 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
# File lib/sequel/database/dataset.rb, line 44 def fetch(sql, *args, &block) ds = dataset.with_sql(sql, *args) ds.each(&block) if block ds end
Returns a new dataset with the from method invoked. If a block is given, it is used as a filter on the dataset.
DB.from(:items) # SELECT * FROM items DB.from(:items){id > 2} # SELECT * FROM items WHERE (id > 2)
# File lib/sequel/database/dataset.rb, line 55 def from(*args, &block) ds = dataset.from(*args) block ? ds.filter(&block) : ds end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version{}} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb, line 65 def select(*args, &block) dataset.select(*args, &block) end
This methods involve the Database's connection pool.
The Database subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb, line 17 def self.adapter_class(scheme) return scheme if scheme.is_a?(Class) scheme = scheme.to_s.gsub('-', '_').to_sym unless klass = ADAPTER_MAP[scheme] # attempt to load the adapter file begin Sequel.tsk_require "sequel/adapters/#{scheme}" rescue LoadError => e raise Sequel.convert_exception_class(e, AdapterNotFound) end # make sure we actually loaded the adapter unless klass = ADAPTER_MAP[scheme] raise AdapterNotFound, "Could not load #{scheme} adapter: adapter class not registered in ADAPTER_MAP" end end klass end
Returns the scheme symbol for the Database class.
# File lib/sequel/database/connecting.rb, line 39 def self.adapter_scheme @scheme end
Connects to a database. See Sequel.connect.
# File lib/sequel/database/connecting.rb, line 44 def self.connect(conn_string, opts = {}) case conn_string when String if match = /\A(jdbc|do):/.match(conn_string) c = adapter_class(match[1].to_sym) opts = {:uri=>conn_string}.merge(opts) else uri = URI.parse(conn_string) scheme = uri.scheme scheme = :dbi if scheme =~ /\Adbi-/ c = adapter_class(scheme) uri_options = c.send(:uri_to_options, uri) uri.query.split('&').collect{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? uri_options.to_a.each{|k,v| uri_options[k] = URI.unescape(v) if v.is_a?(String)} opts = uri_options.merge(opts) opts[:adapter] = scheme end when Hash opts = conn_string.merge(opts) c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) else raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" end # process opts a bit opts = opts.inject({}) do |m, (k,v)| k = :user if k.to_s == 'username' m[k.to_sym] = v m end begin db = c.new(opts) db.test_connection if opts[:test] && db.send(:typecast_value_boolean, opts[:test]) result = yield(db) if block_given? ensure if block_given? db.disconnect if db ::Sequel::DATABASES.delete(db) end end block_given? ? result : db end
Sets the default single_threaded mode for new databases. See Sequel.single_threaded=.
# File lib/sequel/database/connecting.rb, line 88 def self.single_threaded=(value) @@single_threaded = value end
Returns the scheme symbol for this instance's class, which reflects which adapter is being used. In some cases, this can be the same as the database_type (for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb, line 120 def adapter_scheme self.class.adapter_scheme end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Intended for use with master/slave or shard configurations where it is useful to add new server hosts at runtime.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it's value is overridden with the value provided.
DB.add_servers(:f=>{:host=>"hash_host_f"})
# File lib/sequel/database/connecting.rb, line 133 def add_servers(servers) @opts[:servers] = @opts[:servers] ? @opts[:servers].merge(servers) : servers @pool.add_servers(servers.keys) end
Connects to the database. This method should be overridden by descendants.
# File lib/sequel/database/connecting.rb, line 139 def connect(server) raise NotImplemented, "#connect should be overridden by adapters" 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).
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb, line 152 def database_type adapter_scheme end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
:servers |
Should be a symbol specifing the server to disconnect from, or an array of symbols to specify multiple servers. |
Example:
DB.disconnect # All servers DB.disconnect(:servers=>:server1) # Single server DB.disconnect(:servers=>[:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb, line 166 def disconnect(opts = {}) pool.disconnect(opts) end
Yield a new Database instance for every server in the connection pool. Intended for use in sharded environments where there is a need to make schema modifications (DDL queries) on each shard.
DB.each_server{|db| db.create_table(:users){primary_key :id; String :name}}
# File lib/sequel/database/connecting.rb, line 175 def each_server(&block) servers.each{|s| self.class.connect(server_opts(s), &block)} end
Dynamically remove existing servers from the connection pool. Intended for use with master/slave or shard configurations where it is useful to remove existing server hosts at runtime.
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb, line 189 def remove_servers(*servers) if @opts[:servers] && !@opts[:servers].empty? servs = @opts[:servers].dup servers.flatten! servers.each{|s| servs.delete(s)} @opts[:servers] = servs @pool.remove_servers(servers) end end
An array of servers/shards for this Database object.
DB.servers # Unsharded: => [:default] DB.servers # Sharded: => [:default, :server1, :server2]
# File lib/sequel/database/connecting.rb, line 203 def servers pool.servers end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb, line 208 def single_threaded? @single_threaded end
Acquires a database connection, yielding it to the passed block. This is useful if you want to make sure the same connection is used for all database queries in the block. It is also useful if you want to gain direct access to the underlying connection object if you need to do something Sequel does not natively support.
If a server option is given, acquires a connection for that specific server, instead of the :default server.
DB.synchronize do |conn| ... end
# File lib/sequel/database/connecting.rb, line 224 def synchronize(server=nil, &block) @pool.hold(server || :default, &block) end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb, line 232 def test_connection(server=nil) synchronize(server){|conn|} true end
This methods change the default behavior of this database's datasets.
The default class to use for datasets
The class to use for creating datasets. Should respond to new with the Database argument as the first argument, and an optional options hash.
The method to call on identifiers going into the database
# File lib/sequel/database/dataset_defaults.rb, line 21 def self.identifier_input_method @@identifier_input_method end
Set the method to call on identifiers going into the database See Sequel.identifier_input_method=.
# File lib/sequel/database/dataset_defaults.rb, line 27 def self.identifier_input_method=(v) @@identifier_input_method = v || "" end
The method to call on identifiers coming from the database
# File lib/sequel/database/dataset_defaults.rb, line 32 def self.identifier_output_method @@identifier_output_method end
Set the method to call on identifiers coming from the database See Sequel.identifier_output_method=.
# File lib/sequel/database/dataset_defaults.rb, line 38 def self.identifier_output_method=(v) @@identifier_output_method = v || "" end
Sets the default quote_identifiers mode for new databases. See Sequel.quote_identifiers=.
# File lib/sequel/database/dataset_defaults.rb, line 44 def self.quote_identifiers=(value) @@quote_identifiers = value end
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb, line 59 def dataset_class=(c) unless @dataset_modules.empty? c = Class.new(c) @dataset_modules.each{|m| c.send(:include, m)} end @dataset_class = c end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class as the new dataset_class, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database object uses.
Examples:
# Introspec columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end
# File lib/sequel/database/dataset_defaults.rb, line 89 def extend_datasets(mod=nil, &block) raise(Error, "must provide either mod or block, not both") if mod && block mod = Module.new(&block) if block if @dataset_modules.empty? @dataset_modules = [mod] @dataset_class = Class.new(@dataset_class) else @dataset_modules << mod end @dataset_class.send(:include, mod) end
The method to call on identifiers going into the database
# File lib/sequel/database/dataset_defaults.rb, line 102 def identifier_input_method case @identifier_input_method when nil @identifier_input_method = @opts.fetch(:identifier_input_method, (@@identifier_input_method.nil? ? identifier_input_method_default : @@identifier_input_method)) @identifier_input_method == "" ? nil : @identifier_input_method when "" nil else @identifier_input_method end end
Set the method to call on identifiers going into the database:
DB[:items] # SELECT * FROM items DB.identifier_input_method = :upcase DB[:items] # SELECT * FROM ITEMS
# File lib/sequel/database/dataset_defaults.rb, line 119 def identifier_input_method=(v) reset_schema_utility_dataset @identifier_input_method = v || "" end
The method to call on identifiers coming from the database
# File lib/sequel/database/dataset_defaults.rb, line 125 def identifier_output_method case @identifier_output_method when nil @identifier_output_method = @opts.fetch(:identifier_output_method, (@@identifier_output_method.nil? ? identifier_output_method_default : @@identifier_output_method)) @identifier_output_method == "" ? nil : @identifier_output_method when "" nil else @identifier_output_method end end
Set the method to call on identifiers coming from the database:
DB[:items].first # {:id=>1, :name=>'foo'} DB.identifier_output_method = :upcase DB[:items].first # {:ID=>1, :NAME=>'foo'}
# File lib/sequel/database/dataset_defaults.rb, line 142 def identifier_output_method=(v) reset_schema_utility_dataset @identifier_output_method = v || "" end
Set whether to quote identifiers (columns and tables) for this database:
DB[:items] # SELECT * FROM items DB.quote_identifiers = true DB[:items] # SELECT * FROM "items"
# File lib/sequel/database/dataset_defaults.rb, line 152 def quote_identifiers=(v) reset_schema_utility_dataset @quote_identifiers = v end
Returns true if the database quotes identifiers.
# File lib/sequel/database/dataset_defaults.rb, line 158 def quote_identifiers? return @quote_identifiers unless @quote_identifiers.nil? @quote_identifiers = @opts.fetch(:quote_identifiers, (@@quote_identifiers.nil? ? quote_identifiers_default : @@quote_identifiers)) end
This methods affect relating to the logging of executed SQL.
Numeric specifying the duration beyond which queries are logged at warn level instead of info level.
Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb, line 21 def log_info(message, args=nil) log_each(:info, args ? "#{message}; #{args.inspect}" : message) end
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb, line 27 def log_yield(sql, args=nil) return yield if @loggers.empty? sql = "#{sql}; #{args.inspect}" if args start = Time.now begin yield rescue => e log_each(:error, "#{e.class}: #{e.message.strip}: #{sql}") raise ensure log_duration(Time.now - start, sql) unless e end end
These methods don't fit neatly into another category.
Used for checking/removing leading zeroes from strings so they don't get interpreted as octal.
Replacement string when replacing leading zeroes.
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
The default schema to use, should generally be nil | |
:disconnection_proc |
A proc used to disconnect the connection |
A string method symbol to call on identifiers going into the database | |
A string method symbol to call on identifiers coming from the database | |
:logger |
A specific logger to use |
:loggers |
An array of loggers to use |
:quote_identifiers |
Whether to quote identifiers |
:servers |
A hash specifying a server/shard specific options, keyed by shard symbol |
:single_threaded |
Whether to use a single-threaded connection pool |
Method to use to log SQL to a logger, :info by default. |
All options given are also passed to the connection pool. If a block is given, it is used as the connection_proc for the ConnectionPool.
# File lib/sequel/database/misc.rb, line 42 def initialize(opts = {}, &block) @opts ||= opts @opts = connection_pool_default_options.merge(@opts) @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) self.log_warn_duration = @opts[:log_warn_duration] @opts[:disconnection_proc] ||= proc{|conn| disconnect_connection(conn)} block ||= proc{|server| connect(server)} @opts[:servers] = {} if @opts[:servers].is_a?(String) @opts[:adapter_class] = self.class @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, @@single_threaded)) @schemas = {} @default_schema = @opts.fetch(:default_schema, default_schema_default) @prepared_statements = {} @transactions = {} @identifier_input_method = nil @identifier_output_method = nil @quote_identifiers = nil @timezone = nil @dataset_class = dataset_class_default @dataset_modules = [] self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info @pool = ConnectionPool.get_pool(@opts, &block) ::Sequel::DATABASES.push(self) end
If a transaction is not currently in process, yield to the block immediately. Otherwise, add the block to the list of blocks to call after the currently in progress transaction commits (and only if it commits). Options:
:server |
The server/shard to use. |
# File lib/sequel/database/misc.rb, line 74 def after_commit(opts={}, &block) raise Error, "must provide block to after_commit" unless block synchronize(opts[:server]) do |conn| if h = @transactions[conn] raise Error, "cannot call after_commit in a prepared transaction" if h[:prepare] (h[:after_commit] ||= []) << block else yield end end end
If a transaction is not currently in progress, ignore the block. Otherwise, add the block to the list of the blocks to call after the currently in progress transaction rolls back (and only if it rolls back). Options:
:server |
The server/shard to use. |
# File lib/sequel/database/misc.rb, line 91 def after_rollback(opts={}, &block) raise Error, "must provide block to after_rollback" unless block synchronize(opts[:server]) do |conn| if h = @transactions[conn] raise Error, "cannot call after_rollback in a prepared transaction" if h[:prepare] (h[:after_rollback] ||= []) << block end end end
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision DB.cast_type_literal(:foo) # foo
# File lib/sequel/database/misc.rb, line 105 def cast_type_literal(type) type_literal(:type=>type) 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.
# File lib/sequel/extensions/schema_dumper.rb, line 13 def dump_indexes_migration(options={}) ts = tables(options) Sequel.migration do up do#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_indexes(t, :add_index, options)}.reject{|x| x == ''}.join("\n\n").gsub(/^/o, ' ')} end down do#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_indexes(t, :drop_index, options)}.reject{|x| x == ''}.join("\n\n").gsub(/^/o, ' ')} endend 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).
# File lib/sequel/extensions/schema_dumper.rb, line 37 def dump_schema_migration(options={}) ts = tables(options) Sequel.migration do up do#{ts.sort_by{|t| t.to_s}.map{|t| dump_table_schema(t, options)}.join("\n\n").gsub(/^/o, ' ')} end down do drop_table(#{ts.sort_by{|t| t.to_s}.inspect[1...-1]}) endend 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.
# File lib/sequel/extensions/schema_dumper.rb, line 54 def dump_table_schema(table, options={}) table = table.value.to_s if table.is_a?(SQL::Identifier) raise(Error, "must provide table as a Symbol, String, or Sequel::SQL::Identifier") unless [String, Symbol].any?{|c| table.is_a?(c)} s = schema(table).dup pks = s.find_all{|x| x.last[:primary_key] == true}.map{|x| x.first} options = options.merge(:single_pk=>true) if pks.length == 1 m = method(:column_schema_to_generator_opts) im = method(:index_to_generator_opts) begin indexes = indexes(table).sort_by{|k,v| k.to_s} if options[:indexes] != false rescue Sequel::NotImplemented nil end gen = Schema::Generator.new(self) do s.each{|name, info| send(*m.call(name, info, options))} primary_key(pks) if !@primary_key && pks.length > 0 indexes.each{|iname, iopts| send(:index, iopts[:columns], im.call(table, iname, iopts))} if indexes end commands = [gen.dump_columns, gen.dump_constraints, gen.dump_indexes].reject{|x| x == ''}.join("\n\n") "create_table(#{table.inspect}#{', :ignore_index_errors=>true' if !options[:same_db] && options[:indexes] != false && indexes && !indexes.empty?}) do\n#{commands.gsub(/^/o, ' ')}\nend" end
Convert the given timestamp from the application's timezone, to the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb, line 112 def from_application_timestamp(v) Sequel.convert_output_timestamp(v, timezone) end
Return true if already in a transaction given the options, false otherwise. Respects the :server option for selecting a shard.
# File lib/sequel/database/misc.rb, line 119 def in_transaction?(opts={}) synchronize(opts[:server]){|conn| !!@transactions[conn]} 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).
# File lib/sequel/database/misc.rb, line 126 def inspect "#<#{self.class}: #{(uri rescue opts).inspect}>" end
Proxy the literal call to the dataset.
DB.literal(1) # 1 DB.literal(:a) # a DB.literal('a') # 'a'
# File lib/sequel/database/misc.rb, line 135 def literal(v) schema_utility_dataset.literal(v) end
Return a dataset modified by the query block
# File lib/sequel/extensions/query.rb, line 8 def query(&block) dataset.query(&block) end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb, line 141 def serial_primary_key_options {:primary_key => true, :type => Integer, :auto_increment => true} end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/misc.rb, line 147 def supports_create_table_if_not_exists? false end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/misc.rb, line 153 def supports_prepared_transactions? false end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/misc.rb, line 158 def supports_savepoints? false end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/misc.rb, line 163 def supports_transaction_isolation_levels? false end
The timezone to use for this database, defaulting to Sequel.database_timezone.
# File lib/sequel/database/misc.rb, line 168 def timezone @timezone || Sequel.database_timezone end
Convert the given timestamp to the application's timezone, from the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb, line 175 def to_application_timestamp(v) Sequel.convert_timestamp(v, timezone) 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.
# File lib/sequel/database/misc.rb, line 184 def typecast_value(column_type, value) return nil if value.nil? meth = "typecast_value_#{column_type}" begin respond_to?(meth, true) ? send(meth, value) : value rescue ArgumentError, TypeError => e raise Sequel.convert_exception_class(e, InvalidValue) end end
Returns the URI identifying the database, which may not be the same as the URI used when connecting. This method can raise an error if the database used options instead of a connection string, and will not include uri parameters.
Sequel.connect('postgres://localhost/db?user=billg').url # => "postgres://billg@localhost/db"
# File lib/sequel/database/misc.rb, line 202 def uri uri = URI::Generic.new( adapter_scheme.to_s, nil, @opts[:host], @opts[:port], nil, "/#{@opts[:database]}", nil, nil, nil ) uri.user = @opts[:user] uri.password = @opts[:password] if uri.user uri.to_s end
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