can i write complex queries in hyperledger composer

Question

我必须从资产中检索特定属性，例如从employeetable中选择名称。是否可以在Hyperledger Composer中获取特定属性

Answer 1

Yes, here the official documentation

https://hyperledger.github.io/composer/unstable/reference/query-language

And the specific example

query findEmployee{
    description: "Select employee based on the name"
    statement:
        SELECT org.example.Employee
            WHERE (firstName == _$nameParam)
}

Answer 2

In composer rest server, you can use API with filter fields . Such as {"fields": ["name", "description"]"} It will return only those fields instead of full objects.

Reference: https://hyperledger.github.io/composer/latest/business-network/query It said only where is currently support, but fields can be used as well.