Module: JdbcSpec::PostgreSQL

Defined in:
lib/jdbc_adapter/jdbc_postgre.rb

Defined Under Namespace

Modules: Column

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.adapter_matcher(name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 27

def self.adapter_matcher(name, *)
  name =~ /postgre/i ? self : false
end

.column_selector ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 31

def self.column_selector
  [/postgre/i, lambda {|cfg,col| col.extend(::JdbcSpec::PostgreSQL::Column)}]
end

.extended(mod) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 21

def self.extended(mod)
  mod.class_eval do
    alias_chained_method :insert, :query_dirty, :insert
  end
end

.jdbc_connection_class ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 35

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

Instance Method Details

#_execute(sql, name = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 352

def _execute(sql, name = nil)
    case sql.strip
    when /\A\(?\s*(select|show)/i then
      @connection.execute_query(sql)
    else
      @connection.execute_update(sql)
    end
end

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



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 439

def add_column(table_name, column_name, type, options = {})
  execute("ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit])}")
  change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
  if options[:null] == false
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)} = '#{options[:default]}'") if options[:default]
    execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} SET NOT NULL")
  end
end

#add_order_by_for_association_limiting!(sql, options) ⇒ Object

ORDER BY clause for the passed order option.

PostgreSQL does not allow arbitrary ordering when using DISTINCT ON, so we work around this by wrapping the sql as a sub-select and ordering in that query.



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 386

def add_order_by_for_association_limiting!(sql, options)
  return sql if options[:order].blank?

  order = options[:order].split(',').collect { |s| s.strip }.reject(&:blank?)
  order.map! { |s| 'DESC' if s =~ /\bdesc$/i }
  order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{s}" }.join(', ')

  sql.replace "SELECT * FROM (#{sql}) AS id_list ORDER BY #{order}"
end

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

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 448

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  begin
    execute "ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit])}"
  rescue ActiveRecord::StatementInvalid
    # This is PG7, so we use a more arcane way of doing it.
    begin_db_transaction
    add_column(table_name, "#{column_name}_ar_tmp", type, options)
    execute "UPDATE #{table_name} SET #{column_name}_ar_tmp = CAST(#{column_name} AS #{type_to_sql(type, options[:limit])})"
    remove_column(table_name, column_name)
    rename_column(table_name, "#{column_name}_ar_tmp", column_name)
    commit_db_transaction
  end
  change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
end

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 463

def change_column_default(table_name, column_name, default) #:nodoc:
  execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT '#{default}'"
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 467

def change_column_null(table_name, column_name, null, default = nil)
  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
  execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
end

#columns(table_name, name = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 263

def columns(table_name, name=nil)
  schema_name = "public"
  if table_name =~ /\./
    parts = table_name.split(/\./)
    table_name = parts.pop
    schema_name = parts.join(".")
  end
  @connection.columns_internal(table_name, name, schema_name)
end

#create_database(name, options = {}) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 316

def create_database(name, options = {})
  execute "CREATE DATABASE \"#{name}\" ENCODING='#{options[:encoding] || 'utf8'}'"
end

#default_sequence_name(table_name, pk = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 147

def default_sequence_name(table_name, pk = nil)
  default_pk, default_seq = pk_and_sequence_for(table_name)
  default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq"
end

#disable_referential_integrity(&block) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 428

def disable_referential_integrity(&block) #:nodoc:
  execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} DISABLE TRIGGER ALL" }.join(";"))
  yield
ensure
  execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} ENABLE TRIGGER ALL" }.join(";"))
end

#distinct(columns, order_by) ⇒ Object

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

PostgreSQL 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/jdbc_adapter/jdbc_postgre.rb', line 367

def distinct(columns, order_by)
  return "DISTINCT #{columns}" if order_by.blank?

  # construct a clean list of column names from the ORDER BY clause, removing
  # any asc/desc modifiers
  order_columns = order_by.split(',').collect { |s| s.split.first }
  order_columns.delete_if(&:blank?)
  order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" }

  # return a DISTINCT ON() clause that's distinct on the columns we want but includes
  # all the required columns for the ORDER BY to work properly
  sql = "DISTINCT ON (#{columns}) #{columns}, "
  sql << order_columns * ', '
end

#drop_database(name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 320

def drop_database(name)
  execute "DROP DATABASE \"#{name}\""
end

#escape_bytea(s) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 408

def escape_bytea(s)
  if s
    result = ''
    s.each_byte { |c| result << sprintf('\\\\%03o', c) }
    result
  end
end

#indexes(table_name, name = nil) ⇒ Object

From postgresql_adapter.rb



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 274

def indexes(table_name, name = nil)
  result = select_rows(<<-SQL, name)
    SELECT i.relname, d.indisunique, a.attname
      FROM pg_class t, pg_class i, pg_index d, pg_attribute a
     WHERE i.relkind = 'i'
       AND d.indexrelid = i.oid
       AND d.indisprimary = 'f'
       AND t.oid = d.indrelid
       AND t.relname = '#{table_name}'
       AND a.attrelid = t.oid
       AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum
          OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum
          OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum
          OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum
          OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )
    ORDER BY i.relname
  SQL

  current_index = nil
  indexes = []

  result.each do |row|
    if current_index != row[0]
      indexes << ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, row[0], row[1] == "t", [])
      current_index = row[0]
    end

    indexes.last.columns << row[2]
  end

  indexes
end

#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 226

def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
  # Extract the table from the insert sql. Yuck.
  table = sql.split(" ", 4)[2].gsub('"', '')

  # Try an insert with 'returning id' if available (PG >= 8.2)
  if supports_insert_with_returning? && id_value.nil? && false # FIXME:
    # Disabled, as it causes:
    # ActiveRecord::ActiveRecordError: A result was returned when none was expected
    # This was previously disabled because postgresql_version returned 0
    pk, sequence_name = *pk_and_sequence_for(table) unless pk
    if pk
      id_value = select_value("#{sql} RETURNING #{quote_column_name(pk)}")
      clear_query_cache #FIXME: Why now?
      return id_value
    end
  end

  # Otherwise, plain insert
  execute(sql, name)

  # Don't need to look up id_value if we already have it.
  # (and can't in case of non-sequence PK)
  unless id_value
    # If neither pk nor sequence name is given, look them up.
    unless pk || sequence_name
      pk, sequence_name = *pk_and_sequence_for(table)
    end

    # If a pk is given, fallback to default sequence name.
    # Don't fetch last insert id for a table without a pk.
    if pk && sequence_name ||= default_sequence_name(table, pk)
      id_value = last_insert_id(table, sequence_name)
    end
  end
  id_value
end

#last_insert_id(table, sequence_name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 307

def last_insert_id(table, sequence_name)
  Integer(select_value("SELECT currval('#{sequence_name}')"))
end

#modify_types(tp) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 88

def modify_types(tp)
  tp[:primary_key] = "serial primary key"
  tp[:string][:limit] = 255
  tp[:integer][:limit] = nil
  tp[:boolean][:limit] = nil
  tp
end

#pk_and_sequence_for(table) ⇒ Object

Find a table’s primary key and sequence.



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 179

def pk_and_sequence_for(table) #:nodoc:
  # First try looking for a sequence with a dependency on the
  # given table's primary key.
  result = select(<<-end_sql, 'PK and serial sequence')[0]
      SELECT attr.attname, seq.relname
      FROM pg_class      seq,
           pg_attribute  attr,
           pg_depend     dep,
           pg_namespace  name,
           pg_constraint cons
      WHERE seq.oid           = dep.objid
        AND seq.relkind       = 'S'
        AND attr.attrelid     = dep.refobjid
        AND attr.attnum       = dep.refobjsubid
        AND attr.attrelid     = cons.conrelid
        AND attr.attnum       = cons.conkey[1]
        AND cons.contype      = 'p'
        AND dep.refobjid      = '#{table}'::regclass
    end_sql

  if result.nil? or result.empty?
    # If that fails, try parsing the primary key's default value.
    # Support the 7.x and 8.0 nextval('foo'::text) as well as
    # the 8.1+ nextval('foo'::regclass).
    result = query(<<-end_sql, 'PK and custom sequence')[0]
        SELECT attr.attname,
          CASE
            WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
              substr(split_part(def.adsrc, '''', 2),
                     strpos(split_part(def.adsrc, '''', 2), '.')+1)
            ELSE split_part(def.adsrc, '''', 2)
          END as relname
        FROM pg_class       t
        JOIN pg_attribute   attr ON (t.oid = attrelid)
        JOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)
        JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])
        WHERE t.oid = '#{table}'::regclass
          AND cons.contype = 'p'
          AND def.adsrc ~* 'nextval'
      end_sql
  end

  [result["attname"], result["relname"]]
rescue
  nil
end

#postgresql_version ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 96

def postgresql_version
  @postgresql_version ||=
    begin
      value = select_value('SELECT version()')
      if value =~ /PostgreSQL (\d+)\.(\d+)\.(\d+)/
        ($1.to_i * 10000) + ($2.to_i * 100) + $3.to_i
      else
        0
      end
    end
end

#quote(value, column = nil) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 396

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

  if value.kind_of?(String) && column && column.type == :binary
    "'#{escape_bytea(value)}'"
  elsif column && column.type == :primary_key
    return value.to_s
  else
    super
  end
end

#quote_column_name(name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 416

def quote_column_name(name)
  %("#{name}")
end

#quote_regclass(table_name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 172

def quote_regclass(table_name)
  table_name.to_s.split('.').map do |part| 
    part =~ /".*"/i ? part : quote_table_name(part)
  end.join('.')  
end

#quoted_date(value) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 420

def quoted_date(value) #:nodoc:
  if value.acts_like?(:time) && value.respond_to?(:usec)
    "#{super}.#{sprintf("%06d", value.usec)}"
  else
    super
  end
end

#recreate_database(name) ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 311

def recreate_database(name)
  drop_database(name)
  create_database(name)
end

#remove_index(table_name, options) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 478

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

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 474

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{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/jdbc_adapter/jdbc_postgre.rb', line 435

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

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

Resets sequence to the max value of the table’s pk if present.



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 153

def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc:
  unless pk and sequence
    default_pk, default_sequence = pk_and_sequence_for(table)
    pk ||= default_pk
    sequence ||= default_sequence
  end
  if pk
    if sequence
      quoted_sequence = quote_column_name(sequence)

      select_value <<-end_sql, 'Reset sequence'
          SELECT setval('#{quoted_sequence}', (SELECT COALESCE(MAX(#{quote_column_name pk})+(SELECT increment_by FROM #{quoted_sequence}), (SELECT min_value FROM #{quoted_sequence})) FROM #{quote_table_name(table)}), false)
        end_sql
    else
      @logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger
    end
  end
end

#structure_dump ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 324

def structure_dump
  database = @config[:database]
  if database.nil?
    if @config[:url] =~ /\/([^\/]*)$/
      database = $1
    else
      raise "Could not figure out what database this url is for #{@config["url"]}"
    end
  end

  ENV['PGHOST']     = @config[:host] if @config[:host]
  ENV['PGPORT']     = @config[:port].to_s if @config[:port]
  ENV['PGPASSWORD'] = @config[:password].to_s if @config[:password]
  search_path = @config[:schema_search_path]
  search_path = "--schema=#{search_path}" if search_path

  @connection.connection.close
  begin
    definition = `pg_dump -i -U "#{@config[:username]}" -s -x -O #{search_path} #{database}`
    raise "Error dumping database" if $?.exitstatus == 1

    # need to patch away any references to SQL_ASCII as it breaks the JDBC driver
    definition.gsub(/SQL_ASCII/, 'UNICODE')
  ensure
    reconnect!
  end
end

#supports_ddl_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 133

def supports_ddl_transactions?
  true
end

#supports_insert_with_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 129

def supports_insert_with_returning?
  postgresql_version >= 80200
end

#supports_migrations? ⇒ Boolean

Does PostgreSQL support migrations?

Returns:

  • (Boolean) 


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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 109

def supports_migrations?
  true
end

#supports_savepoints? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 137

def supports_savepoints?
  true
end

#supports_standard_conforming_strings? ⇒ Boolean

Does PostgreSQL support standard conforming strings?

Returns:

  • (Boolean) 


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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 114

def supports_standard_conforming_strings?
  # Temporarily set the client message level above error to prevent unintentional
  # error messages in the logs when working on a PostgreSQL database server that
  # does not support standard conforming strings.
  client_min_messages_old = client_min_messages
  self.client_min_messages = 'panic'

  # postgres-pr does not raise an exception when client_min_messages is set higher
  # than error and "SHOW standard_conforming_strings" fails, but returns an empty
  # PGresult instead.
  has_support = select('SHOW standard_conforming_strings').to_a[0][0] rescue false
  self.client_min_messages = client_min_messages_old
  has_support
end

#table_alias_length ⇒ Object

Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 143

def table_alias_length
  @table_alias_length ||= (postgresql_version >= 80000 ? select('SHOW max_identifier_length').to_a[0][0].to_i : 63)
end

#tables ⇒ Object 



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 494

def tables
  @connection.tables(database_name, nil, nil, ["TABLE"])
end

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

:nodoc:



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# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 482

def type_to_sql(type, limit = nil, precision = nil, scale = nil) #:nodoc:
  return super unless type.to_s == 'integer'

  if limit.nil? || limit == 4
    'integer'
  elsif limit < 4
    'smallint'
  else
    'bigint'
  end
end