Module: PgSaurus::ConnectionAdapters::PostgreSQLAdapter::TriggerMethods

Included in:
PgSaurus::ConnectionAdapters::PostgreSQLAdapter
Defined in:
lib/pg_saurus/connection_adapters/postgresql_adapter/trigger_methods.rb

Overview

Provides methods to extend ActiveRecord::ConnectionAdapters::PostgreSQLAdapter to support db triggers.

Instance Method Summary collapse

Instance Method Details

#create_trigger(table_name, proc_name, event, options = {}) ⇒ Object

See lib/pg_saurus/connection_adapters/trigger_methods.rb



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# File 'lib/pg_saurus/connection_adapters/postgresql_adapter/trigger_methods.rb', line 11

def create_trigger(table_name, proc_name, event, options = {})
  proc_name = "#{proc_name}"
  proc_name = "#{proc_name}()" unless proc_name.end_with?(')')

  for_each   = options[:for_each] || 'ROW'
  constraint = options[:constraint]

  sql = "CREATE #{!!constraint ? "CONSTRAINT " : ""}TRIGGER #{trigger_name(proc_name, options)}\n  #{event}\n"

  sql << "  ON #{quote_table_or_view(table_name, options)}\n"
  if constraint
    sql << if options[:deferrable]
             "  DEFERRABLE INITIALLY #{!!options[:initially_deferred] ? 'DEFERRED' : 'IMMEDIATE'}\n"
           else
             "  NOT DEFERRABLE\n"
           end
  end
  sql << "  FOR EACH #{for_each}\n"
  if condition = options[:condition]
    sql << "  WHEN (#{condition})\n"
  end
  sql << "  EXECUTE PROCEDURE #{proc_name}"

  execute sql
end

#remove_trigger(table_name, proc_name, options = {}) ⇒ Object

See lib/pg_saurus/connection_adapters/trigger_methods.rb



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# File 'lib/pg_saurus/connection_adapters/postgresql_adapter/trigger_methods.rb', line 38

def remove_trigger(table_name, proc_name, options = {})
  execute "DROP TRIGGER #{trigger_name(proc_name, options)} ON #{quote_table_or_view(table_name, options)}"
end

#supports_triggers? ⇒ Boolean

:nodoc

Returns:

  • (Boolean) 


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# File 'lib/pg_saurus/connection_adapters/postgresql_adapter/trigger_methods.rb', line 6

def supports_triggers?
  true
end

#triggers ⇒ Array<::PgSaurus::ConnectionAdapters::TriggerDefinition>

Returns the listing of currently defined db triggers

Returns:



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# File 'lib/pg_saurus/connection_adapters/postgresql_adapter/trigger_methods.rb', line 45

def triggers
  res = select_all <<-SQL
    SELECT n.nspname as schema,
           c.relname as table,
           t.tgname as trigger_name,
           t.tgenabled as enable_mode,
           t.tgdeferrable as is_deferrable,
           t.tginitdeferred as is_initially_deferrable,
           pg_catalog.pg_get_triggerdef(t.oid, true) as trigger_definition
    FROM pg_catalog.pg_trigger t
      INNER JOIN pg_catalog.pg_class c ON c.oid = t.tgrelid
      INNER JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
    WHERE c.relkind IN ('r', 'v')
      AND NOT t.tgisinternal
    ORDER BY 1, 2, 3;
  SQL

  res.inject([]) do |buffer, row|
    schema                = row['schema']
    table                 = row['table']
    trigger_name          = row['trigger_name']
    is_deferrable         = row['is_deferrable']
    is_initially_deferred = row['is_initially_deferred']

    trigger_definition = row['trigger_definition']

    is_constraint = is_constraint?(trigger_definition)
    proc_name     = parse_proc_name(trigger_definition)
    event         = parse_event(trigger_definition, trigger_name)
    condition     = parse_condition(trigger_definition)

    for_every = !!(trigger_definition =~ /FOR[\s]EACH[\s]ROW/) ? :row : :statement

    if proc_name && event
      buffer << ::PgSaurus::ConnectionAdapters::TriggerDefinition.new(
        trigger_name,
        proc_name,
        is_constraint,
        event,
        for_every,
        is_deferrable,
        is_initially_deferred,
        condition,
        table,
        schema
      )
    end
    buffer
  end
end