如何在ETS中订购商品？

Question

我插入ETS很多项目是这样的：

ets:insert{{users, jim, 9}} 
ets:insert{{users, ham, 3}} 
ets:insert{{users, why, 2}} 
ets:insert{{users, dhh, 3}} 
ets:insert{{users, zend, 4}} 

因此，如何在项目由一个数字得到有序列表？

[ 
    {users, why, 2}, 
    {users, ham, 3}, 
    {users, dhh, 3}, 
    {users, zend, 4}, 
    {users, jim, 9} 
] 

Answer 1

通过使用lists:keysort/2像这样：

1> Result = [{users, jim, 9}, 
      {users, ham, 3}, 
      {users, why, 2}, 
      {users, dhh, 3}, 
      {users,zend, 4}]. 
[{users,jim,9}, 
{users,ham,3}, 
{users,why,2}, 
{users,dhh,3}, 
{users,zend,4}] 
2> lists:keysort(3, Result). 
[{users,why,2}, 
{users,ham,3}, 
{users,dhh,3}, 
{users,zend,4}, 
{users,jim,9}]