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-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb107
-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb9
-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb38
-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract_adapter.rb26
-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb123
-rw-r--r--activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb136
-rw-r--r--activerecord/lib/active_record/connection_adapters/schema_cache.rb72
-rw-r--r--activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb31
8 files changed, 395 insertions, 147 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 77a5fe1efb..e32154780a 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -2,6 +2,7 @@ require 'thread'
require 'monitor'
require 'set'
require 'active_support/core_ext/module/synchronization'
+require 'active_support/core_ext/module/deprecation'
module ActiveRecord
# Raised when a connection could not be obtained within the connection
@@ -59,8 +60,6 @@ module ActiveRecord
class ConnectionPool
attr_accessor :automatic_reconnect
attr_reader :spec, :connections
- attr_reader :columns, :columns_hash, :primary_keys, :tables
- attr_reader :column_defaults
# Creates a new ConnectionPool object. +spec+ is a ConnectionSpecification
# object which describes database connection information (e.g. adapter,
@@ -85,72 +84,7 @@ module ActiveRecord
@connections = []
@checked_out = []
@automatic_reconnect = true
- @tables = {}
@visitor = nil
-
- @columns = Hash.new do |h, table_name|
- h[table_name] = with_connection do |conn|
-
- # Fetch a list of columns
- conn.columns(table_name, "#{table_name} Columns").tap do |columns|
-
- # set primary key information
- columns.each do |column|
- column.primary = column.name == primary_keys[table_name]
- end
- end
- end
- end
-
- @columns_hash = Hash.new do |h, table_name|
- h[table_name] = Hash[columns[table_name].map { |col|
- [col.name, col]
- }]
- end
-
- @column_defaults = Hash.new do |h, table_name|
- h[table_name] = Hash[columns[table_name].map { |col|
- [col.name, col.default]
- }]
- end
-
- @primary_keys = Hash.new do |h, table_name|
- h[table_name] = with_connection do |conn|
- table_exists?(table_name) ? conn.primary_key(table_name) : 'id'
- end
- end
- end
-
- # A cached lookup for table existence.
- def table_exists?(name)
- return true if @tables.key? name
-
- with_connection do |conn|
- conn.tables.each { |table| @tables[table] = true }
- @tables[name] = true if !@tables.key?(name) && conn.table_exists?(name)
- end
-
- @tables.key? name
- end
-
- # Clears out internal caches:
- #
- # * columns
- # * columns_hash
- # * tables
- def clear_cache!
- @columns.clear
- @columns_hash.clear
- @column_defaults.clear
- @tables.clear
- end
-
- # Clear out internal caches for table with +table_name+.
- def clear_table_cache!(table_name)
- @columns.delete table_name
- @columns_hash.delete table_name
- @column_defaults.delete table_name
- @primary_keys.delete table_name
end
# Retrieve the connection associated with the current thread, or call
@@ -227,6 +161,34 @@ module ActiveRecord
end
end
+ def columns
+ with_connection do |c|
+ c.schema_cache.columns
+ end
+ end
+ deprecate :columns
+
+ def columns_hash
+ with_connection do |c|
+ c.schema_cache.columns_hash
+ end
+ end
+ deprecate :columns_hash
+
+ def primary_keys
+ with_connection do |c|
+ c.schema_cache.primary_keys
+ end
+ end
+ deprecate :primary_keys
+
+ def clear_cache!
+ with_connection do |c|
+ c.schema_cache.clear!
+ end
+ end
+ deprecate :clear_cache!
+
# Return any checked-out connections back to the pool by threads that
# are no longer alive.
def clear_stale_cached_connections!
@@ -301,16 +263,7 @@ module ActiveRecord
private
def new_connection
- connection = ActiveRecord::Base.send(spec.adapter_method, spec.config)
-
- # TODO: This is a bit icky, and in the long term we may want to change the method
- # signature for connections. Also, if we switch to have one visitor per
- # connection (and therefore per thread), we can get rid of the thread-local
- # variable in Arel::Visitors::ToSql.
- @visitor ||= connection.class.visitor_for(self)
- connection.visitor = @visitor
-
- connection
+ ActiveRecord::Base.send(spec.adapter_method, spec.config)
end
def current_connection_id #:nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 82f564e41d..6f135b56b5 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -6,7 +6,7 @@ require 'bigdecimal/util'
module ActiveRecord
module ConnectionAdapters #:nodoc:
- class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths) #:nodoc:
+ class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders) #:nodoc:
end
# Abstract representation of a column definition. Instances of this type
@@ -46,13 +46,13 @@ module ActiveRecord
# +change_table+ is actually of this type:
#
# class SomeMigration < ActiveRecord::Migration
- # def self.up
+ # def up
# create_table :foo do |t|
# puts t.class # => "ActiveRecord::ConnectionAdapters::TableDefinition"
# end
# end
#
- # def self.down
+ # def down
# ...
# end
# end
@@ -252,7 +252,7 @@ module ActiveRecord
# Appends <tt>:datetime</tt> columns <tt>:created_at</tt> and
# <tt>:updated_at</tt> to the table.
def timestamps(*args)
- options = args.extract_options!
+ options = { :null => false }.merge(args.extract_options!)
column(:created_at, :datetime, options)
column(:updated_at, :datetime, options)
end
@@ -479,4 +479,3 @@ module ActiveRecord
end
end
-
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 8e3ba1297e..faa42e2d19 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -1,4 +1,5 @@
require 'active_support/core_ext/array/wrap'
+require 'active_support/deprecation/reporting'
module ActiveRecord
module ConnectionAdapters # :nodoc:
@@ -339,6 +340,14 @@ module ActiveRecord
# CREATE INDEX by_name_surname ON accounts(name(10), surname(15))
#
# Note: SQLite doesn't support index length
+ #
+ # ====== Creating an index with a sort order (desc or asc, asc is the default)
+ # add_index(:accounts, [:branch_id, :party_id, :surname], :order => {:branch_id => :desc, :part_id => :asc})
+ # generates
+ # CREATE INDEX by_branch_desc_party ON accounts(branch_id DESC, party_id ASC, surname)
+ #
+ # Note: mysql doesn't yet support index order (it accepts the syntax but ignores it)
+ #
def add_index(table_name, column_name, options = {})
index_name, index_type, index_columns = add_index_options(table_name, column_name, options)
execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{index_columns})"
@@ -405,7 +414,7 @@ module ActiveRecord
def dump_schema_information #:nodoc:
sm_table = ActiveRecord::Migrator.schema_migrations_table_name
- migrated = select_values("SELECT version FROM #{sm_table}")
+ migrated = select_values("SELECT version FROM #{sm_table} ORDER BY version")
migrated.map { |v| "INSERT INTO #{sm_table} (version) VALUES ('#{v}');" }.join("\n\n")
end
@@ -426,6 +435,7 @@ module ActiveRecord
si_table = Base.table_name_prefix + 'schema_info' + Base.table_name_suffix
if table_exists?(si_table)
+ ActiveRecord::Deprecation.warn "Usage of the schema table `#{si_table}` is deprecated. Please switch to using `schema_migrations` table"
old_version = select_value("SELECT version FROM #{quote_table_name(si_table)}").to_i
assume_migrated_upto_version(old_version)
@@ -507,8 +517,8 @@ module ActiveRecord
# ===== Examples
# add_timestamps(:suppliers)
def add_timestamps(table_name)
- add_column table_name, :created_at, :datetime
- add_column table_name, :updated_at, :datetime
+ add_column table_name, :created_at, :datetime, :null => false
+ add_column table_name, :updated_at, :datetime, :null => false
end
# Removes the timestamp columns (created_at and updated_at) from the table definition.
@@ -520,9 +530,29 @@ module ActiveRecord
end
protected
+ def add_index_sort_order(option_strings, column_names, options = {})
+ if options.is_a?(Hash) && order = options[:order]
+ case order
+ when Hash
+ column_names.each {|name| option_strings[name] += " #{order[name].to_s.upcase}" if order.has_key?(name)}
+ when String
+ column_names.each {|name| option_strings[name] += " #{order.upcase}"}
+ end
+ end
+
+ return option_strings
+ end
+
# Overridden by the mysql adapter for supporting index lengths
def quoted_columns_for_index(column_names, options = {})
- column_names.map {|name| quote_column_name(name) }
+ option_strings = Hash[column_names.map {|name| [name, '']}]
+
+ # add index sort order if supported
+ if supports_index_sort_order?
+ option_strings = add_index_sort_order(option_strings, column_names, options)
+ end
+
+ column_names.map {|name| quote_column_name(name) + option_strings[name]}
end
def options_include_default?(options)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 4c3a8f7233..75e568b557 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -3,6 +3,7 @@ require 'bigdecimal'
require 'bigdecimal/util'
require 'active_support/core_ext/benchmark'
require 'active_support/deprecation'
+require 'active_record/connection_adapters/schema_cache'
module ActiveRecord
module ConnectionAdapters # :nodoc:
@@ -51,6 +52,7 @@ module ActiveRecord
define_callbacks :checkout, :checkin
attr_accessor :visitor
+ attr_reader :schema_cache
def initialize(connection, logger = nil) #:nodoc:
@active = nil
@@ -60,24 +62,7 @@ module ActiveRecord
@open_transactions = 0
@instrumenter = ActiveSupport::Notifications.instrumenter
@visitor = nil
- end
-
- # Returns a visitor instance for this adaptor, which conforms to the Arel::ToSql interface
- def self.visitor_for(pool) # :nodoc:
- adapter = pool.spec.config[:adapter]
-
- if Arel::Visitors::VISITORS[adapter]
- ActiveSupport::Deprecation.warn(
- "Arel::Visitors::VISITORS is deprecated and will be removed. Database adapters " \
- "should define a visitor_for method which returns the appropriate visitor for " \
- "the database. For example, MysqlAdapter.visitor_for(pool) returns " \
- "Arel::Visitors::MySQL.new(pool)."
- )
-
- Arel::Visitors::VISITORS[adapter].new(pool)
- else
- Arel::Visitors::ToSql.new(pool)
- end
+ @schema_cache = SchemaCache.new self
end
# Returns the human-readable name of the adapter. Use mixed case - one
@@ -130,6 +115,11 @@ module ActiveRecord
false
end
+ # Does this adapter support index sort order?
+ def supports_index_sort_order?
+ false
+ end
+
# QUOTING ==================================================
# Override to return the quoted table name. Defaults to column quoting.
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index dd573ba569..f143fd348e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -127,10 +127,7 @@ module ActiveRecord
super(connection, logger)
@connection_options, @config = connection_options, config
@quoted_column_names, @quoted_table_names = {}, {}
- end
-
- def self.visitor_for(pool) # :nodoc:
- Arel::Visitors::MySQL.new(pool)
+ @visitor = Arel::Visitors::MySQL.new self
end
def adapter_name #:nodoc:
@@ -155,6 +152,12 @@ module ActiveRecord
true
end
+ # Technically MySQL allows to create indexes with the sort order syntax
+ # but at the moment (5.5) it doesn't yet implement them
+ def supports_index_sort_order?
+ true
+ end
+
def native_database_types
NATIVE_DATABASE_TYPES
end
@@ -222,6 +225,80 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
+ def explain(arel)
+ sql = "EXPLAIN #{to_sql(arel)}"
+ start = Time.now
+ result = exec_query(sql, 'EXPLAIN')
+ elapsed = Time.now - start
+
+ ExplainPrettyPrinter.new.pp(result, elapsed)
+ end
+
+ class ExplainPrettyPrinter # :nodoc:
+ # Pretty prints the result of a EXPLAIN in a way that resembles the output of the
+ # MySQL shell:
+ #
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # | 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | |
+ # | 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where |
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # 2 rows in set (0.00 sec)
+ #
+ # This is an exercise in Ruby hyperrealism :).
+ def pp(result, elapsed)
+ widths = compute_column_widths(result)
+ separator = build_separator(widths)
+
+ pp = []
+
+ pp << separator
+ pp << build_cells(result.columns, widths)
+ pp << separator
+
+ result.rows.each do |row|
+ pp << build_cells(row, widths)
+ end
+
+ pp << separator
+ pp << build_footer(result.rows.length, elapsed)
+
+ pp.join("\n") + "\n"
+ end
+
+ private
+
+ def compute_column_widths(result)
+ [].tap do |widths|
+ result.columns.each_with_index do |column, i|
+ cells_in_column = [column] + result.rows.map {|r| r[i].nil? ? 'NULL' : r[i].to_s}
+ widths << cells_in_column.map(&:length).max
+ end
+ end
+ end
+
+ def build_separator(widths)
+ padding = 1
+ '+' + widths.map {|w| '-' * (w + (padding*2))}.join('+') + '+'
+ end
+
+ def build_cells(items, widths)
+ cells = []
+ items.each_with_index do |item, i|
+ item = 'NULL' if item.nil?
+ justifier = item.is_a?(Numeric) ? 'rjust' : 'ljust'
+ cells << item.to_s.send(justifier, widths[i])
+ end
+ '| ' + cells.join(' | ') + ' |'
+ end
+
+ def build_footer(nrows, elapsed)
+ rows_label = nrows == 1 ? 'row' : 'rows'
+ "#{nrows} #{rows_label} in set (%.2f sec)" % elapsed
+ end
+ end
+
# Executes the SQL statement in the context of this connection.
def execute(sql, name = nil)
if name == :skip_logging
@@ -309,11 +386,11 @@ module ActiveRecord
sql = "SHOW TABLES"
end
- select_all(sql).map do |table|
+ select_all(sql).map { |table|
table.delete('Table_type')
sql = "SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}"
exec_without_stmt(sql).first['Create Table'] + ";\n\n"
- end.join("")
+ }.join
end
# Drops the database specified on the +name+ attribute
@@ -496,8 +573,8 @@ module ActiveRecord
# Returns a table's primary key and belonging sequence.
def pk_and_sequence_for(table)
- execute_and_free("DESCRIBE #{quote_table_name(table)}", 'SCHEMA') do |result|
- keys = each_hash(result).select { |row| row[:Key] == 'PRI' }.map { |row| row[:Field] }
+ execute_and_free("SHOW INDEX FROM #{quote_table_name(table)} WHERE Key_name = 'PRIMARY'", 'SCHEMA') do |result|
+ keys = each_hash(result).map { |row| row[:Column_name] }
keys.length == 1 ? [keys.first, nil] : nil
end
end
@@ -526,17 +603,29 @@ module ActiveRecord
protected
+ def add_index_length(option_strings, column_names, options = {})
+ if options.is_a?(Hash) && length = options[:length]
+ case length
+ when Hash
+ column_names.each {|name| option_strings[name] += "(#{length[name]})" if length.has_key?(name)}
+ when Fixnum
+ column_names.each {|name| option_strings[name] += "(#{length})"}
+ end
+ end
+
+ return option_strings
+ end
+
def quoted_columns_for_index(column_names, options = {})
- length = options[:length] if options.is_a?(Hash)
+ option_strings = Hash[column_names.map {|name| [name, '']}]
- case length
- when Hash
- column_names.map {|name| length[name] ? "#{quote_column_name(name)}(#{length[name]})" : quote_column_name(name) }
- when Fixnum
- column_names.map {|name| "#{quote_column_name(name)}(#{length})"}
- else
- column_names.map {|name| quote_column_name(name) }
- end
+ # add index length
+ option_strings = add_index_length(option_strings, column_names, options)
+
+ # add index sort order
+ option_strings = add_index_sort_order(option_strings, column_names, options)
+
+ column_names.map {|name| quote_column_name(name) + option_strings[name]}
end
def translate_exception(exception, message)
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index d859843260..2f01fbb829 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -247,6 +247,10 @@ module ActiveRecord
true
end
+ def supports_index_sort_order?
+ true
+ end
+
class StatementPool < ConnectionAdapters::StatementPool
def initialize(connection, max)
super
@@ -278,13 +282,24 @@ module ActiveRecord
cache.clear
end
+ def delete(sql_key)
+ dealloc cache[sql_key]
+ cache.delete sql_key
+ end
+
private
def cache
@cache[$$]
end
def dealloc(key)
- @connection.query "DEALLOCATE #{key}"
+ @connection.query "DEALLOCATE #{key}" if connection_active?
+ end
+
+ def connection_active?
+ @connection.status == PGconn::CONNECTION_OK
+ rescue PGError
+ false
end
end
@@ -292,6 +307,7 @@ module ActiveRecord
def initialize(connection, logger, connection_parameters, config)
super(connection, logger)
@connection_parameters, @config = connection_parameters, config
+ @visitor = Arel::Visitors::PostgreSQL.new self
# @local_tz is initialized as nil to avoid warnings when connect tries to use it
@local_tz = nil
@@ -308,10 +324,6 @@ module ActiveRecord
@local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
end
- def self.visitor_for(pool) # :nodoc:
- Arel::Visitors::PostgreSQL.new(pool)
- end
-
# Clears the prepared statements cache.
def clear_cache!
@statements.clear
@@ -502,6 +514,48 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
+ def explain(arel)
+ sql = "EXPLAIN #{to_sql(arel)}"
+ ExplainPrettyPrinter.new.pp(exec_query(sql))
+ end
+
+ class ExplainPrettyPrinter # :nodoc:
+ # Pretty prints the result of a EXPLAIN in a way that resembles the output of the
+ # PostgreSQL shell:
+ #
+ # QUERY PLAN
+ # ------------------------------------------------------------------------------
+ # Nested Loop Left Join (cost=0.00..37.24 rows=8 width=0)
+ # Join Filter: (posts.user_id = users.id)
+ # -> Index Scan using users_pkey on users (cost=0.00..8.27 rows=1 width=4)
+ # Index Cond: (id = 1)
+ # -> Seq Scan on posts (cost=0.00..28.88 rows=8 width=4)
+ # Filter: (posts.user_id = 1)
+ # (6 rows)
+ #
+ def pp(result)
+ header = result.columns.first
+ lines = result.rows.map(&:first)
+
+ # We add 2 because there's one char of padding at both sides, note
+ # the extra hyphens in the example above.
+ width = [header, *lines].map(&:length).max + 2
+
+ pp = []
+
+ pp << header.center(width).rstrip
+ pp << '-' * width
+
+ pp += lines.map {|line| " #{line}"}
+
+ nrows = result.rows.length
+ rows_label = nrows == 1 ? 'row' : 'rows'
+ pp << "(#{nrows} #{rows_label})"
+
+ pp.join("\n") + "\n"
+ end
+ end
+
# Executes a SELECT query and returns an array of rows. Each row is an
# array of field values.
def select_rows(sql, name = nil)
@@ -743,16 +797,15 @@ module ActiveRecord
# Returns an array of indexes for the given table.
def indexes(table_name, name = nil)
- schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
result = query(<<-SQL, name)
- SELECT distinct i.relname, d.indisunique, d.indkey, t.oid
+ SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid
FROM pg_class t
INNER JOIN pg_index d ON t.oid = d.indrelid
INNER JOIN pg_class i ON d.indexrelid = i.oid
WHERE i.relkind = 'i'
AND d.indisprimary = 'f'
AND t.relname = '#{table_name}'
- AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (#{schemas}) )
+ AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) )
ORDER BY i.relname
SQL
@@ -761,7 +814,8 @@ module ActiveRecord
index_name = row[0]
unique = row[1] == 't'
indkey = row[2].split(" ")
- oid = row[3]
+ inddef = row[3]
+ oid = row[4]
columns = Hash[query(<<-SQL, "Columns for index #{row[0]} on #{table_name}")]
SELECT a.attnum, a.attname
@@ -771,7 +825,12 @@ module ActiveRecord
SQL
column_names = columns.values_at(*indkey).compact
- column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names)
+
+ # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
+ desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
+ orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
+
+ column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders)
end.compact
end
@@ -815,7 +874,7 @@ module ActiveRecord
# Returns the active schema search path.
def schema_search_path
- @schema_search_path ||= query('SHOW search_path')[0][0]
+ @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0]
end
# Returns the current client message level.
@@ -911,12 +970,14 @@ module ActiveRecord
# Example:
# rename_table('octopuses', 'octopi')
def rename_table(name, new_name)
+ clear_cache!
execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
end
# Adds a new column to the named table.
# See TableDefinition#column for details of the options you can use.
def add_column(table_name, column_name, type, options = {})
+ clear_cache!
add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
add_column_options!(add_column_sql, options)
@@ -925,6 +986,7 @@ module ActiveRecord
# Changes the column of a table.
def change_column(table_name, column_name, type, options = {})
+ clear_cache!
quoted_table_name = quote_table_name(table_name)
execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
@@ -935,10 +997,12 @@ module ActiveRecord
# Changes the default value of a table column.
def change_column_default(table_name, column_name, default)
+ clear_cache!
execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
end
def change_column_null(table_name, column_name, null, default = nil)
+ clear_cache!
unless null || default.nil?
execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
end
@@ -947,6 +1011,7 @@ module ActiveRecord
# Renames a column in a table.
def rename_column(table_name, column_name, new_column_name)
+ clear_cache!
execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
end
@@ -1030,27 +1095,54 @@ module ActiveRecord
end
private
+ FEATURE_NOT_SUPPORTED = "0A000" # :nodoc:
+
def exec_no_cache(sql, binds)
@connection.async_exec(sql)
end
def exec_cache(sql, binds)
- sql_key = "#{schema_search_path}-#{sql}"
+ begin
+ stmt_key = prepare_statement sql
+
+ # Clear the queue
+ @connection.get_last_result
+ @connection.send_query_prepared(stmt_key, binds.map { |col, val|
+ type_cast(val, col)
+ })
+ @connection.block
+ @connection.get_last_result
+ rescue PGError => e
+ # Get the PG code for the failure. Annoyingly, the code for
+ # prepared statements whose return value may have changed is
+ # FEATURE_NOT_SUPPORTED. Check here for more details:
+ # http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573
+ code = e.result.result_error_field(PGresult::PG_DIAG_SQLSTATE)
+ if FEATURE_NOT_SUPPORTED == code
+ @statements.delete sql_key(sql)
+ retry
+ else
+ raise e
+ end
+ end
+ end
+
+ # Returns the statement identifier for the client side cache
+ # of statements
+ def sql_key(sql)
+ "#{schema_search_path}-#{sql}"
+ end
+
+ # Prepare the statement if it hasn't been prepared, return
+ # the statement key.
+ def prepare_statement(sql)
+ sql_key = sql_key(sql)
unless @statements.key? sql_key
nextkey = @statements.next_key
@connection.prepare nextkey, sql
@statements[sql_key] = nextkey
end
-
- key = @statements[sql_key]
-
- # Clear the queue
- @connection.get_last_result
- @connection.send_query_prepared(key, binds.map { |col, val|
- type_cast(val, col)
- })
- @connection.block
- @connection.get_last_result
+ @statements[sql_key]
end
# The internal PostgreSQL identifier of the money data type.
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
new file mode 100644
index 0000000000..b14b37ce89
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -0,0 +1,72 @@
+module ActiveRecord
+ module ConnectionAdapters
+ class SchemaCache
+ attr_reader :columns, :columns_hash, :primary_keys, :tables
+ attr_reader :column_defaults
+ attr_reader :connection
+
+ def initialize(conn)
+ @connection = conn
+ @tables = {}
+
+ @columns = Hash.new do |h, table_name|
+ h[table_name] =
+ # Fetch a list of columns
+ conn.columns(table_name, "#{table_name} Columns").tap do |cs|
+ # set primary key information
+ cs.each do |column|
+ column.primary = column.name == primary_keys[table_name]
+ end
+ end
+ end
+
+ @columns_hash = Hash.new do |h, table_name|
+ h[table_name] = Hash[columns[table_name].map { |col|
+ [col.name, col]
+ }]
+ end
+
+ @column_defaults = Hash.new do |h, table_name|
+ h[table_name] = Hash[columns[table_name].map { |col|
+ [col.name, col.default]
+ }]
+ end
+
+ @primary_keys = Hash.new do |h, table_name|
+ h[table_name] = table_exists?(table_name) ?
+ conn.primary_key(table_name) : 'id'
+ end
+ end
+
+ # A cached lookup for table existence.
+ def table_exists?(name)
+ return @tables[name] if @tables.key? name
+
+ connection.tables.each { |table| @tables[table] = true }
+ @tables[name] = connection.table_exists?(name) if !@tables.key?(name)
+
+ @tables[name]
+ end
+
+ # Clears out internal caches:
+ #
+ # * columns
+ # * columns_hash
+ # * tables
+ def clear!
+ @columns.clear
+ @columns_hash.clear
+ @column_defaults.clear
+ @tables.clear
+ end
+
+ # Clear out internal caches for table with +table_name+.
+ def clear_table_cache!(table_name)
+ @columns.delete table_name
+ @columns_hash.delete table_name
+ @column_defaults.delete table_name
+ @primary_keys.delete table_name
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 1932a849ee..c11f82a33f 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -89,10 +89,7 @@ module ActiveRecord
@statements = StatementPool.new(@connection,
config.fetch(:statement_limit) { 1000 })
@config = config
- end
-
- def self.visitor_for(pool) # :nodoc:
- Arel::Visitors::SQLite.new(pool)
+ @visitor = Arel::Visitors::SQLite.new self
end
def adapter_name #:nodoc:
@@ -157,6 +154,10 @@ module ActiveRecord
sqlite_version >= '3.1.0'
end
+ def supports_index_sort_order?
+ sqlite_version >= '3.3.0'
+ end
+
def native_database_types #:nodoc:
{
:primary_key => default_primary_key_type,
@@ -218,6 +219,25 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
+ def explain(arel)
+ sql = "EXPLAIN QUERY PLAN #{to_sql(arel)}"
+ 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 = [])
log(sql, name, binds) do
@@ -413,6 +433,8 @@ module ActiveRecord
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)
end
end
end
@@ -467,6 +489,7 @@ module ActiveRecord
@definition.column(column_name, column.type,
:limit => column.limit, :default => column.default,
+ :precision => column.precision, :scale => column.scale,
:null => column.null)
end
@definition.primary_key(primary_key(from)) if primary_key(from)