модуль ActiveRecord::ConnectionAdapters::PostgreSQL::SchemaStatements
Общедоступные методы экземпляра
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 236
def client_min_messages
query_value("SHOW client_min_messages", "SCHEMA")
end Возвращает текущий уровень сообщений клиента.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 241
def client_min_messages=(level)
execute("SET client_min_messages TO '#{level}'", "SCHEMA")
end Устанавливает уровень сообщений клиента.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 188
def collation
query_value("SELECT datcollate FROM pg_database WHERE datname = current_database()", "SCHEMA")
end Возвращает текущее сопоставление базы данных.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 22
def create_database(name, options = {})
options = { encoding: "utf8" }.merge!(options.symbolize_keys)
option_string = options.each_with_object(+"") do |(key, value), memo|
memo << case key
when :owner
" OWNER = \"#{value}\""
when :template
" TEMPLATE = \"#{value}\""
when :encoding
" ENCODING = '#{value}'"
when :collation
" LC_COLLATE = '#{value}'"
when :ctype
" LC_CTYPE = '#{value}'"
when :tablespace
" TABLESPACE = \"#{value}\""
when :connection_limit
" CONNECTION LIMIT = #{value}"
else
""
end
end
execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
end Создаёт новую базу данных PostgreSQL. Параметры включают :owner, :template, :encoding (по умолчанию utf8), :collation, :ctype, :tablespace, и :connection_limit (обратите внимание, что MySQL использует :charset, в то время как PostgreSQL использует :encoding).
Пример:
create_database config[:database], config create_database 'foo_development', encoding: 'unicode'
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 209
def create_schema(schema_name)
execute "CREATE SCHEMA #{quote_schema_name(schema_name)}"
end Создаёт схему для заданного имени схемы.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 193
def ctype
query_value("SELECT datctype FROM pg_database WHERE datname = current_database()", "SCHEMA")
end Возвращает текущий тип данных базы данных.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 173
def current_database
query_value("SELECT current_database()", "SCHEMA")
end Возвращает имя текущей базы данных.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 178
def current_schema
query_value("SELECT current_schema", "SCHEMA")
end Возвращает имя текущей схемы.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 214
def drop_schema(schema_name, options = {})
execute "DROP SCHEMA#{' IF EXISTS' if options[:if_exists]} #{quote_schema_name(schema_name)} CASCADE"
end Удаляет схему для заданного имени схемы.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 183
def encoding
query_value("SELECT pg_encoding_to_char(encoding) FROM pg_database WHERE datname = current_database()", "SCHEMA")
end Возвращает текущий формат кодирования базы данных.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 480
def foreign_keys(table_name)
scope = quoted_scope(table_name)
fk_info = exec_query(<<~SQL, "SCHEMA")
SELECT t2.oid::regclass::text AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete, c.convalidated AS valid
FROM pg_constraint c
JOIN pg_class t1 ON c.conrelid = t1.oid
JOIN pg_class t2 ON c.confrelid = t2.oid
JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
JOIN pg_namespace t3 ON c.connamespace = t3.oid
WHERE c.contype = 'f'
AND t1.relname = #{scope[:name]}
AND t3.nspname = #{scope[:schema]}
ORDER BY c.conname
SQL
fk_info.map do |row|
options = {
column: row["column"],
name: row["name"],
primary_key: row["primary_key"]
}
options[:on_delete] = extract_foreign_key_action(row["on_delete"])
options[:on_update] = extract_foreign_key_action(row["on_update"])
options[:validate] = row["valid"]
ForeignKeyDefinition.new(table_name, row["to_table"], options)
end
end # File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 515 def foreign_table_exists?(table_name) query_values(data_source_sql(table_name, type: "FOREIGN TABLE"), "SCHEMA").any? if table_name.present? end
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 511 def foreign_tables query_values(data_source_sql(type: "FOREIGN TABLE"), "SCHEMA") end
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 67
def index_name_exists?(table_name, index_name)
table = quoted_scope(table_name)
index = quoted_scope(index_name)
query_value(<<~SQL, "SCHEMA").to_i > 0
SELECT COUNT(*)
FROM pg_class t
INNER JOIN pg_index d ON t.oid = d.indrelid
INNER JOIN pg_class i ON d.indexrelid = i.oid
LEFT JOIN pg_namespace n ON n.oid = i.relnamespace
WHERE i.relkind = 'i'
AND i.relname = #{index[:name]}
AND t.relname = #{table[:name]}
AND n.nspname = #{index[:schema]}
SQL
end Проверяет существование индекса с заданным именем.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 474
def rename_index(table_name, old_name, new_name)
validate_index_length!(table_name, new_name)
execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
end Переименовывает индекс таблицы. Вызывает ошибку, если длина нового имени индекса превышает допустимый предел.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 377
def rename_table(table_name, new_name)
clear_cache!
execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
pk, seq = pk_and_sequence_for(new_name)
if pk
idx = "#{table_name}_pkey"
new_idx = "#{new_name}_pkey"
execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_table_name(new_idx)}"
if seq && seq.identifier == "#{table_name}_#{pk}_seq"
new_seq = "#{new_name}_#{pk}_seq"
execute "ALTER TABLE #{seq.quoted} RENAME TO #{quote_table_name(new_seq)}"
end
end
rename_table_indexes(table_name, new_name)
end Переименовывает таблицу. Также переименовывает последовательность первичного ключа таблицы, если имя последовательности существует и совпадает с значением по умолчанию Active Record.
Пример:
rename_table('octopuses', 'octopi')
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 62
def schema_exists?(name)
query_value("SELECT COUNT(*) FROM pg_namespace WHERE nspname = #{quote(name)}", "SCHEMA").to_i > 0
end Возвращает true, если схема существует.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 198
def schema_names
query_values(<<~SQL, "SCHEMA")
SELECT nspname
FROM pg_namespace
WHERE nspname !~ '^pg_.*'
AND nspname NOT IN ('information_schema')
ORDER by nspname;
SQL
end Возвращает массив имён схем.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 231
def schema_search_path
@schema_search_path ||= query_value("SHOW search_path", "SCHEMA")
end Возвращает активный путь поиска схем.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 223
def schema_search_path=(schema_csv)
if schema_csv
execute("SET search_path TO #{schema_csv}", "SCHEMA")
@schema_search_path = schema_csv
end
end Устанавливает путь поиска схем в строку с именами схем, разделёнными запятыми. Имена, начинающиеся с $, должны быть заключены в кавычки (например, $user => '$user'). См.: www.postgresql.org/docs/current/static/ddl-schemas.html
Этого метода не следует вызывать вручную, он должен быть установлен в файле database.yml.
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 254
def serial_sequence(table, column)
query_value("SELECT pg_get_serial_sequence(#{quote(table)}, #{quote(column)})", "SCHEMA")
end # File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 579 def validate_constraint(table_name, constraint_name) return unless supports_validate_constraints? at = create_alter_table table_name at.validate_constraint constraint_name execute schema_creation.accept(at) end
Проверяет заданное ограничение.
Проверяет ограничение с именем constraint_name в таблице accounts.
validate_constraint :accounts, :constraint_name
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 603 def validate_foreign_key(from_table, to_table = nil, **options) return unless supports_validate_constraints? fk_name_to_validate = foreign_key_for!(from_table, to_table: to_table, **options).name validate_constraint from_table, fk_name_to_validate end
Проверяет заданный внешний ключ.
Проверяет внешний ключ в таблице accounts.branch_id.
validate_foreign_key :accounts, :branches
Проверяет внешний ключ в таблице accounts.owner_id.
validate_foreign_key :accounts, column: :owner_id
Проверяет внешний ключ с именем special_fk_name в таблице accounts.
validate_foreign_key :accounts, name: :special_fk_name
Хэш options принимает те же ключи, что и SchemaStatements#add_foreign_key.
© 2004–2019 David Heinemeier Hansson
Licensed under the MIT License.