Appends a locking clause to an SQL statement. This method modifies
the sql parameter.
# SELECT * FROM suppliers FOR UPDATEadd_lock!'SELECT * FROM suppliers',:lock=>trueadd_lock!'SELECT * FROM suppliers',:lock=>' FOR UPDATE'
# File activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb, line 121
def add_lock!(sql, options)
case lock = options[:lock]
when true; sql << ' FOR UPDATE'
when String; sql << " #{lock}"
end
end