How to retrieve value of a key without having to write the entire key?

[dev-vaayen]

Let's say I have a key which stores information about some children who study at a school. The value is going to be the name of the child

The key looks like:
/schools/schoolName/class/rollNumber
The value is going to be:
Child's_Name

Example
Key:
/schools/ColomboSchool/5th/rollNumber
Value:
Mallinga

My question is: How can I retrieve the name of ALL children who are studying in the ColomboSchool, whose roll number is 22? Let's just assume I do not know or I do not want to enter the class/grade and I want to see all the children that study at ColomboSchool & have roll number 22.

Is there any pre-built command in etcdctl to make this happen? Or how can I find the names of all students studying in ColomboSchool without mentioning their class/grade or rollNumber?

I did use etcdctl get --prefix "/schools/" | grep "ColomboSchool" | grep "22" and was able to retrieve the relevant data. Is there any other way to retrieve data?

[jmhbnz]

Hey @Anand11Yash - Thanks for your question. etcd as a key value store doesn't have complex query capabilities like a traditional relational database, so you need to structure your keys in a way that makes querying feasible.

The approach you are taking with etcdctl get --prefix and then further filter with additional tools like grep makes sense to me. Perhaps just extend your prefix to also include ColomboSchool so one less grep iteration is required.

etcdctl get --prefix "/schools/ColomboSchool" | grep "22"