The document information is shown in Figure 2. When I query through Figure 1, I get undefined. Why?
Dear, here is a question similar to yours that has been answered. Let’s see if your situation is the same as his: /q/10...
There must be definition-related keys in the schema. For example, if there is type in schameA, but you add an additional category to docA during your operation, then querying docA.category will output undefined, because schemaA does not have it
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Dear, here is a question similar to yours that has been answered. Let’s see if your situation is the same as his: /q/10...
There must be definition-related keys in the schema. For example, if there is type in schameA, but you add an additional category to docA during your operation, then querying docA.category will output undefined, because schemaA does not have it