sql · postgresql-dba
Aggregate functions
10 roles need it, 9 as coreUsually level 3: WorkingLesson available
Where it sits
Jobs that need it
- Backend Developer (ASP.NET Core)corelevel 3
- Backend Developer (Go)corelevel 3
- Backend Developer (Java, Spring Boot)corelevel 3
- Backend Developer (Node.js)corelevel 3
- Backend Developer (Python)corelevel 3
- Data Analystcorelevel 3
- Data Engineercorelevel 3
- Full Stack Developer (Java + React)corelevel 3
- Full Stack Developer (Python + React)corelevel 3
- Data Scientistsupportinglevel 2
What level 3 (Working) means
Uses it independently on the job. Level 4 (Strong): handles hard cases, reviews others.
Aggregate functions: common questions
What is Aggregate functions?
Aggregate functions is a skill in sql and postgresql-dba, needed by 10 roles on BootSelf.
Which jobs need Aggregate functions?
Backend Developer (ASP.NET Core), Backend Developer (Go), Backend Developer (Java, Spring Boot), Backend Developer (Node.js), Backend Developer (Python), and 5 more. Most ask for level 3 (Working): uses it independently on the job.
What should I learn before Aggregate functions?
The NULL value.
How do I practise Aggregate functions?
Check your readiness for free, then BootSelf builds a route and short daily learning loops: a little theory, checks on what you get wrong, then a small program.