Module: ArJdbc::Derby

Includes:
Util::TableCopier
Defined in:
lib/arjdbc/derby/adapter.rb,
lib/arjdbc/derby/schema_creation.rb

Defined Under Namespace

Modules: Column Classes: SchemaCreation

Constant Summary collapse

ADAPTER_NAME = 
'Derby'.freeze
NATIVE_DATABASE_TYPES = 
{
  :primary_key => "int GENERATED BY DEFAULT AS identity NOT NULL PRIMARY KEY",
  :string => { :name => "varchar", :limit => 255 }, # 32672
  :text => { :name => "clob" }, # 2,147,483,647
  :char => { :name => "char", :limit => 254 }, # JDBC limit: 254
  :binary => { :name => "blob" }, # 2,147,483,647
  :float => { :name => "float", :limit => 8 }, # DOUBLE PRECISION
  :real => { :name => "real", :limit => 4 }, # JDBC limit: 23
  :double => { :name => "double", :limit => 8 }, # JDBC limit: 52
  :decimal => { :name => "decimal", :precision => 5, :scale => 0 }, # JDBC limit: 31
  :numeric => { :name => "decimal", :precision => 5, :scale => 0 }, # JDBC limit: 31
  :integer => { :name => "integer", :limit => 4 }, # JDBC limit: 10
  :smallint => { :name => "smallint", :limit => 2 }, # JDBC limit: 5
  :bigint => { :name => "bigint", :limit => 8 }, # JDBC limit: 19
  :date => { :name => "date" },
  :time => { :name => "time" },
  :datetime => { :name => "timestamp" },
  :timestamp => { :name => "timestamp" },
  :xml => { :name => "xml" },
  :boolean => { :name => "smallint", :limit => 1 }, # TODO boolean (since 10.7)
  :object => { :name => "object" },
}

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Util::TableCopier

#alter_table, #copy_table, #copy_table_contents, #copy_table_indexes, #move_table

Class Method Details

.arel_visitor_type(config = nil) ⇒ Object

See Also:



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# File 'lib/arjdbc/derby/adapter.rb', line 84

def self.arel_visitor_type(config = nil)
  require 'arel/visitors/derby'; ::Arel::Visitors::Derby
end

.column_selector ⇒ Object

See Also:

  • ActiveRecord::ConnectionAdapters::JdbcColumn#column_types


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# File 'lib/arjdbc/derby/adapter.rb', line 24

def self.column_selector
  [ /derby/i, lambda { |config, column| column.extend(Column) } ]
end

.jdbc_connection_class ⇒ Object

See Also:



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# File 'lib/arjdbc/derby/adapter.rb', line 19

def self.jdbc_connection_class
  ::ActiveRecord::ConnectionAdapters::DerbyJdbcConnection
end

Instance Method Details

#adapter_name ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 90

def adapter_name
  ADAPTER_NAME
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 270

def add_column(table_name, column_name, type, options = {})
  add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(add_column_sql, options)
  execute(add_column_sql)
end

#add_column_options!(sql, options) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 277

def add_column_options!(sql, options)
  options.delete(:default) if options.has_key?(:default) && options[:default].nil?
  sql << " DEFAULT #{quote(options.delete(:default))}" if options.has_key?(:default)
  super
end

#add_limit_offset!(sql, options) ⇒ Object

Note:

Only used with (non-AREL) ActiveRecord 2.3.

See Also:



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# File 'lib/arjdbc/derby/adapter.rb', line 436

def add_limit_offset!(sql, options)
  sql << " OFFSET #{options[:offset]} ROWS" if options[:offset]
  # ROWS/ROW and FIRST/NEXT mean the same
  sql << " FETCH FIRST #{options[:limit]} ROWS ONLY" if options[:limit]
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 291

def change_column(table_name, column_name, type, options = {})
  # TODO this needs a review since now we're likely to be on >= 10.8

  # Notes about changing in Derby:
  #    http://db.apache.org/derby/docs/10.2/ref/rrefsqlj81859.html#rrefsqlj81859__rrefsqlj37860)
  #
  # We support changing columns using the strategy outlined in:
  #    https://issues.apache.org/jira/browse/DERBY-1515
  #
  # This feature has not made it into a formal release and is not in Java 6.
  # We will need to conditionally support this (supposed to arrive for 10.3.0.0).

  # null/not nulling is easy, handle that separately
  if options.include?(:null)
    # This seems to only work with 10.2 of Derby
    if options.delete(:null) == false
      execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} NOT NULL"
    else
      execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} NULL"
    end
  end

  # anything left to do?
  unless options.empty?
    begin
      execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN " <<
              " #{quote_column_name(column_name)} SET DATA TYPE #{type_to_sql(type, options[:limit])}"
    rescue
      transaction do
        temp_new_column_name = "#{column_name}_newtype"
        # 1) ALTER TABLE t ADD COLUMN c1_newtype NEWTYPE;
        add_column table_name, temp_new_column_name, type, options
        # 2) UPDATE t SET c1_newtype = c1;
        execute "UPDATE #{quote_table_name(table_name)} SET " <<
                " #{quote_column_name(temp_new_column_name)} = " <<
                " CAST(#{quote_column_name(column_name)} AS #{type_to_sql(type, options[:limit])})"
        # 3) ALTER TABLE t DROP COLUMN c1;
        remove_column table_name, column_name
        # 4) ALTER TABLE t RENAME COLUMN c1_newtype to c1;
        rename_column table_name, temp_new_column_name, column_name
      end
    end
  end
end

#columns_for_distinct(columns, orders) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 356

def columns_for_distinct(columns, orders)
  return columns if orders.blank?

  # construct a clean list of column names from the ORDER BY clause,
  # removing any ASC/DESC modifiers
  order_columns = [ orders ]; order_columns.flatten! # AR 3.x vs 4.x
  order_columns.map! do |column|
    column = column.to_sql unless column.is_a?(String) # handle AREL node
    column.split(',').collect! { |s| s.split.first }
  end.flatten!
  order_columns.reject!(&:blank?)
  order_columns = order_columns.zip (0...order_columns.size).to_a
  order_columns = order_columns.map { |s, i| "#{s} AS alias_#{i}" }

  columns = [ columns ]; columns.flatten!
  columns.push( *order_columns ).join(', ')
  # return a DISTINCT clause that's distinct on the columns we want but
  # includes all the required columns for the ORDER BY to work properly
end

#configure_connection ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 110

def configure_connection
  # must be done or SELECT...FOR UPDATE won't work how we expect :
  execute("SET ISOLATION = SERIALIZABLE")
  # if a user name was specified upon connection, the user's name is the
  # default schema for the connection, if a schema with that name exists
  set_schema(config[:schema]) if config.key?(:schema)
end

#create_savepoint(name = current_savepoint_name(true)) ⇒ Object

Ensure the savepoint name is unused before creating it.



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# File 'lib/arjdbc/derby/adapter.rb', line 152

def create_savepoint(name = current_savepoint_name(true))
  release_savepoint(name) if @connection.marked_savepoint_names.include?(name)
  super(name)
end

#create_schema(schema) ⇒ Object

Creates a new Derby schema.

See Also:



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# File 'lib/arjdbc/derby/adapter.rb', line 401

def create_schema(schema)
  execute "CREATE SCHEMA #{schema}", 'Create Schema'
end

#current_schema ⇒ String

Returns the current schema name.

Returns:

  • (String) —

    the current schema name



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# File 'lib/arjdbc/derby/adapter.rb', line 387

def current_schema
  @current_schema ||=
    select_value "SELECT CURRENT SCHEMA FROM SYS.SYSSCHEMAS FETCH FIRST 1 ROWS ONLY", 'SCHEMA'
end

#distinct(columns, order_by) ⇒ Object

Note:

This is based on distinct method for the PostgreSQL Adapter.

SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.

Derby requires the ORDER BY columns in the select list for distinct queries, and requires that the ORDER BY include the distinct column.

  distinct("posts.id", "posts.created_at desc")



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# File 'lib/arjdbc/derby/adapter.rb', line 351

def distinct(columns, order_by)
  "DISTINCT #{columns_for_distinct(columns, order_by)}"
end

#drop_schema(schema) ⇒ Object

Drops an existing schema, needs to be empty (no DB objects).



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# File 'lib/arjdbc/derby/adapter.rb', line 406

def drop_schema(schema)
  execute "DROP SCHEMA #{schema} RESTRICT", 'Drop Schema'
end

#empty_insert_statement_value ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 235

def empty_insert_statement_value
  'VALUES ( DEFAULT )' # won't work as Derby does need to know the columns count
end

#execute(sql, name = nil, binds = []) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 443

def execute(sql, name = nil, binds = [])
  sql = to_sql(sql, binds)
  insert = self.class.insert?(sql)
  update = ! insert && ! self.class.select?(sql)
  sql = correct_is_null(sql, insert || update)
  super(sql, name, binds)
end

#index_name_length ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 118

def index_name_length
  128
end

#last_insert_id ⇒ Fixnum

Note:

Check the IDENTITY_VAL_LOCAL function for documentation.

Returns the value of an identity column of the last INSERT statement made over this connection.

Returns:

  • (Fixnum) 


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# File 'lib/arjdbc/derby/adapter.rb', line 455

def last_insert_id
  @connection.identity_val_local
end

#native_database_types ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 146

def native_database_types
  NATIVE_DATABASE_TYPES
end

#primary_keys(table_name) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 377

def primary_keys(table_name)
  @connection.primary_keys table_name.to_s.upcase
end

#quote(value, column = nil) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 158

def quote(value, column = nil)
  return value.quoted_id if value.respond_to?(:quoted_id)
  return value if sql_literal?(value)
  return 'NULL' if value.nil?

  column_type = column && column.type
  if column_type == :string || column_type == :text
    # Derby is not permissive
    # e.g. sending an Integer to a VARCHAR column will fail
    case value
    when BigDecimal then value = value.to_s('F')
    when Numeric then value = value.to_s
    when true, false then value = value.to_s
    when Date, Time then value = quoted_date(value)
    else # on 2.3 attribute serialization needs to_yaml here
      value = value.to_s if ActiveRecord::VERSION::MAJOR >= 3
    end
  end

  case value
  when String, ActiveSupport::Multibyte::Chars
    if column_type == :text
      "CAST('#{quote_string(value)}' AS CLOB)"
    elsif column_type == :binary
      "CAST(X'#{quote_binary(value)}' AS BLOB)"
    elsif column_type == :xml
      "XMLPARSE(DOCUMENT '#{quote_string(value)}' PRESERVE WHITESPACE)"
    elsif column_type == :integer
      value.to_i
    elsif column_type == :float
      value.to_f
    else
      "'#{quote_string(value)}'"
    end
  else
    super
  end
end

#quote_column_name(name) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 425

def quote_column_name(name)
  %Q{"#{name.to_s.upcase.gsub('"', '""')}"}
end

#quote_table_name_for_assignment(table, attr) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 430

def quote_table_name_for_assignment(table, attr)
  quote_column_name(attr)
end

#quoted_date(value) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 198

def quoted_date(value)
  if value.acts_like?(:time) && value.respond_to?(:usec)
    usec = sprintf("%06d", value.usec)
    value = ::ActiveRecord::Base.default_timezone == :utc ? value.getutc : value.getlocal
    "#{value.strftime("%Y-%m-%d %H:%M:%S")}.#{usec}"
  else
    super
  end
end

#remove_column(table_name, *column_names) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 284

def remove_column(table_name, *column_names)
  for column_name in column_names.flatten
    execute "ALTER TABLE #{quote_table_name(table_name)} DROP COLUMN #{quote_column_name(column_name)} RESTRICT"
  end
end

#remove_index(table_name, options) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 261

def remove_index(table_name, options)
  execute "DROP INDEX #{index_name(table_name, options)}"
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 337

def rename_column(table_name, column_name, new_column_name)
  execute "RENAME COLUMN #{quote_table_name(table_name)}.#{quote_column_name(column_name)} " <<
          " TO #{quote_column_name(new_column_name)}"
end

#rename_table(name, new_name) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 266

def rename_table(name, new_name)
  execute "RENAME TABLE #{quote_table_name(name)} TO #{quote_table_name(new_name)}"
end

#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 246

def reset_pk_sequence!(table, pk = nil, sequence = nil)
  klasses = classes_for_table_name(table)
  klass   = klasses.nil? ? nil : klasses.first
  pk      = klass.primary_key unless klass.nil?
  if pk && klass.columns_hash[pk].type == :integer
    reset_sequence!(klass.table_name, pk)
  end
end

#reset_sequence!(table, column, sequence = nil) ⇒ Object

Set the sequence to the max value of the table's column.



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# File 'lib/arjdbc/derby/adapter.rb', line 241

def reset_sequence!(table, column, sequence = nil)
  mpk = select_value("SELECT MAX(#{quote_column_name(column)}) FROM #{quote_table_name(table)}")
  execute("ALTER TABLE #{quote_table_name(table)} ALTER COLUMN #{quote_column_name(column)} RESTART WITH #{mpk.to_i + 1}")
end

#set_schema(schema) ⇒ Object Also known as: current_schema=

Change the current (implicit) Derby schema to be used for this connection.



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# File 'lib/arjdbc/derby/adapter.rb', line 393

def set_schema(schema)
  @current_schema = nil
  execute "SET SCHEMA #{schema}", 'SCHEMA'
end

#table_definition(*args) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 230

def table_definition(*args)
  new_table_definition(TableDefinition, *args)
end

#tables(name = nil) ⇒ Object 



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# File 'lib/arjdbc/derby/adapter.rb', line 382

def tables(name = nil)
  @connection.tables(nil, current_schema)
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

Convert the specified column type to a SQL string.



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# File 'lib/arjdbc/derby/adapter.rb', line 213

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  return super unless NO_LIMIT_TYPES.include?(t = type.to_s.downcase.to_sym)

  native_type = NATIVE_DATABASE_TYPES[t]
  native_type.is_a?(Hash) ? native_type[:name] : native_type
end