对云表达式的部分进行操作
云表达式支持高效的 Part 操作,它是直接在云端运行的.
创建一个云表达式来存储一个记分牌.
In[1]:=
![Click for copyable input](assets.zh/operate-on-parts-of-a-cloud-expression/In_3.png)
ce = CreateCloudExpression[<|
"Alice" -> <|"best" -> 12, "last" -> 3|>,
"Bob" -> <|"best" -> 7, "last" -> 5|>,
"Carlo" -> <|"best" -> 31, "last" -> 12|>|>, "scoreboard"]
Out[1]=
![](assets.zh/operate-on-parts-of-a-cloud-expression/O_3.png)
获取与 Alice 和 Bob 相关的最好成绩.
In[2]:=
![Click for copyable input](assets.zh/operate-on-parts-of-a-cloud-expression/In_4.png)
ce[{"Alice", "Bob"}, "best"]
Out[2]=
![](assets.zh/operate-on-parts-of-a-cloud-expression/O_4.png)
将一个用户的两个分数更新到一个更高值.
In[3]:=
![Click for copyable input](assets.zh/operate-on-parts-of-a-cloud-expression/In_5.png)
ce["Alice", {"best", "last"}] = 24
Out[3]=
![](assets.zh/operate-on-parts-of-a-cloud-expression/O_5.png)
检索更新后的整个云表达式并按照最好成绩排序.
In[4]:=
![Click for copyable input](assets.zh/operate-on-parts-of-a-cloud-expression/In_6.png)
Dataset[Get[ce]][SortBy[-Part[#, "best"] &]]
Out[4]=
![](assets.zh/operate-on-parts-of-a-cloud-expression/O_6.png)