ask echarts how to draw a tree diagram similar to the following xmind ...
vue News item data request is to monitor route changes by clicking on the above categories (so the categories share a data request page). As long as the route changes, the data will be requested, so that the data requested by the page cannot be cach...
< H2 > user table: user field: id,parentid (the ID,0 of the superior is the top level) < H2 > < H2 > Statistical report: report field: time,u_id,pay, description: only one row of data is stored per user per day < H2 > < H2 > user subordinate table: u...
problem description 1. A certain field of a table has a high degree of repetition, so how much repetition is it not suitable for indexing? 2. If a table does not build an index other than the primary key, how old will the table be, such as a slow que...
What data type is the best way to store foreign key id in mongodb? For example, in an article, if you want to store the user id, the foreign key id of the user, should you use the String type or the ObjectId type? ...
system version: win10 nvm version: 1.1.6 settings file content: root: C: Program Files nvm path: C: Program Files nodejs arch: 64 proxy: none node_mirror:npm.taobao.org mirrors node npm_mirror:npm.taobao.org mirrors npm the terminal runs nvm...