To write custom reports, Custom Reports an implementer should be good with SQL statements. Most reports require you to pull database from MySQL / Postgres DB, and having a good grasp on SQL will help.
Given below a set of common SQL clauses an implementer should learn to master custom reports.
- SELECT
- WHERE clause
- HAVING clause
- INNER JOIN
- LEFT OUTER JOIN
- RIGHT OUTER JOIN
- GROUP BY
- ORDER BY
- SUM
- IF
- DATEDIFF
- DATEADD
- CREATE VIEW
- UNION
- INTERESECT
- Sql Functions
Some resources are given below: