I am very new to NSQL. Do you know any tutorial/ manual to learn the basic popular NSQL Syntax?
There is manual for nsql.
This is a helpful site ; http://www.gelscripting.com/#nsql
That is the "Grammar of the NSQL"
If you wanna learn to create your own NSQL you might also consider
1. Create a new query and a portlet based on that. When you create a new NSQL query it is populated by default with a simple query.
SELECT @SELECT:DIM:USER_DEF:IMPLIED:RESOURCE:R.FULL_NAME:RSRC@, @SELECT:DIM_PROP:USER_DEF:IMPLIED:RESOURCE:MR.FULL_NAME:MANAGER@, @SELECT:METRIC:USER_DEF:IMPLIED:COUNT(*):PROJECT_COUNT:AGG@FROM INV_INVESTMENTS I, SRM_RESOURCES R, SRM_RESOURCES MR, CMN_SEC_USERS UWHERE I.CREATED_BY = U.IDAND U.ID = R.USER_IDAND R.MANAGER_ID = MR.USER_IDAND @FILTER@GROUP BY R.FULL_NAME, MR.FULL_NAMEHAVING @HAVING_FILTER@
2. Once you get that working modify that to something else, eg. other fields or other tables for other objects.
3. Look at the queries that exist in the system.
4. Consider putting your SQL query inside a wrapper to simplify the NSQL
SELECT @SELECT:DIM:USER_DEF:IMPLIED:Mysql:UNIQUEID@, @SELECT:DIM_PROP:USER_DEF:IMPLIED:Mysql:Field1:Field1@, @SELECT:DIM_PROP:USER_DEF:IMPLIED:Mysql:Field2:Field2@,
and so onFROM (This is where you have your fancy SQL which could choke a horse, but eventually returns a number of fields and values)
Try to not to use reserved words like start, finish, id etc.
5. If there are errors when you preview try to interpret them to correct the NSQL
6. Ask for help in this community (after you have searched for similar questions.
Right, there you can practice.