如何在ETS中订购商品？

Question

我像这样在ETS中插入了许多项：

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}}

那么，如何通过项目中的一个数字获得有序列表呢？

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

Answer 1

通过像这样使用lists:keysort/2：

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}]