Module: Switchman::ActiveRecord::PostgreSQLAdapter

Defined in:
lib/switchman/active_record/postgresql_adapter.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.prepended(klass) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 4

def self.prepended(klass)
  klass::NATIVE_DATABASE_TYPES[:primary_key] = "bigserial primary key".freeze
end

Instance Method Details

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

copy/paste; use quote_local_table_name



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 9

def create_database(name, options = {})
  options = { encoding: 'utf8' }.merge!(options.symbolize_keys)

  option_string = options.sum do |key, value|
    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_local_table_name(name)}#{option_string}"
end

#current_schemas ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 41

def current_schemas
  select_values("SELECT * FROM unnest(current_schemas(false))")
end

#drop_database(name) ⇒ Object

copy/paste; use quote_local_table_name



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 37

def drop_database(name) #:nodoc:
  execute "DROP DATABASE IF EXISTS #{quote_local_table_name(name)}"
end

#foreign_keys(table_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 185

def foreign_keys(table_name)
  schema = shard.name if use_qualified_names?

  # mostly copy-pasted from AR - only change is to the nspname condition for qualified names support
  fk_info = select_all <<-SQL.strip_heredoc
    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
    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 = #{quote(table_name)}
      AND t3.nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
    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'])

    ::ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.new(table_name, row['to_table'], options)
  end
end

#index_name_exists?(table_name, index_name, default) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 138

def index_name_exists?(table_name, index_name, default)
  schema = shard.name if use_qualified_names?

  exec_query(<<-SQL, 'SCHEMA').rows.first[0].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
      WHERE i.relkind = 'i'
        AND i.relname = '#{index_name}'
        AND t.relname = '#{table_name}'
        AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'} )
  SQL
end

#indexes(table_name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 94

def indexes(table_name)
  schema = shard.name if use_qualified_names?

  result = query(<<-SQL, 'SCHEMA')
     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 = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'} )
    ORDER BY i.relname
  SQL


  result.map do |row|
    index_name = row[0]
    unique = row[1] == 't'
    indkey = row[2].split(" ")
    inddef = row[3]
    oid = row[4]

    columns = Hash[query(<<-SQL, "SCHEMA")]
    SELECT a.attnum, a.attname
    FROM pg_attribute a
    WHERE a.attrelid = #{oid}
    AND a.attnum IN (#{indkey.join(",")})
    SQL

    column_names = columns.stringify_keys.values_at(*indkey).compact

    unless column_names.empty?
      # 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]}] : {}
      where = inddef.scan(/WHERE (.+)$/).flatten[0]
      using = inddef.scan(/USING (.+?) /).flatten[0].to_sym

      ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using)
    end
  end.compact
end

#quote_local_table_name(name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 153

def quote_local_table_name(name)
  # postgres quotes tables and columns the same; just pass through
  # (differs from quote_table_name below by no logic to explicitly
  # qualify the table)
  quote_column_name(name)
end

#quote_table_name(name) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 160

def quote_table_name name
  if ::Rails.version < '4.2'.freeze
    schema, name_part = extract_pg_identifier_from_name(name.to_s)

    if !name_part && use_qualified_names? && shard.name
      schema, name_part = shard.name, schema
    end

    unless name_part
      quote_column_name(schema)
    else
      table_name, name_part = extract_pg_identifier_from_name(name_part)
      "#{quote_column_name(schema)}.#{quote_column_name(table_name)}"
    end
  else

    name = ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
    if !name.schema && use_qualified_names?
      name.instance_variable_set(:@schema, shard.name)
    end
    name.quoted
  end
end

#table_exists?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 59

def table_exists?(name)
  if ::Rails.version < '4.2'
    schema, table = ::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::Utils.extract_schema_and_table(name.to_s)
    return false unless table
    schema ||= shard.name if use_qualified_names?

    binds = [[nil, table]]
    binds << [nil, schema] if schema

    exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
        SELECT COUNT(*)
        FROM pg_class c
        LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
        WHERE c.relkind in ('v','r')
        AND c.relname = '#{table.gsub(/(^"|"$)/,'')}'
        AND n.nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
    SQL
  else
    name =  ::ActiveRecord::ConnectionAdapters::PostgreSQL::Utils.extract_schema_qualified_name(name.to_s)
    return false unless name.identifier
    if !name.schema && use_qualified_names?
      name.instance_variable_set(:@schema, shard.name)
    end

    exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
        SELECT COUNT(*)
        FROM pg_class c
        LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
        WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view
        AND c.relname = '#{name.identifier}'
        AND n.nspname = #{name.schema ? "'#{name.schema}'" : 'ANY (current_schemas(false))'}
    SQL
  end
end

#tables(name = nil) ⇒ Object 



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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 49

def tables(name = nil)
  schema = shard.name if use_qualified_names?

  query(<<-SQL, 'SCHEMA').map { |row| row[0] }
    SELECT tablename
    FROM pg_tables
    WHERE schemaname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
  SQL
end

#use_qualified_names? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/switchman/active_record/postgresql_adapter.rb', line 45

def use_qualified_names?
  @config[:use_qualified_names]
end