Problem with extracting USERID

Question

I have the following code but it didn't seems to work:
Select
COY_C, --Company Code which is the first 3 letterof the userid
Substr(USER_M, 1, 1) || --this part of the code can work but no the rest of the code.
Substr(USER_M, instr(USER_M, ,1,1)+1)||
Substr(USER_M, instr(USER_M, ,1,2)+1)
AS INITIALS from USER_ACCT
where EMP_N = EMP_N;
Below is what i hope to get:
For Example:
Name: Kwok Fu Sing
Company: ACE
USERID generated: ACEZKFS
the NAME and COMPANY CODE is already in the database and i need to display the name and the initial of name and company in the form based on the EMPLOYEE ID entered by the user.From there, i must take out the company code and 3 initial of the NAME.Besides, I got to make sure there is no duplicate in the database as it will be treated as the USERID.
the name is not input by the user but is retireve from the database,and the USERID got to be generated by the system.
How do I generate the company code and 3 initial from the name together and most importantly, making sure there is no duplicates for USERID?
If there are duplicates,
the system got to re-generate the userid again using the second letter of the person name.If the system check again, there is another duplicate, the system got to re-generqate again using the third letter and so on.
For Example:
Name: Kwok Fu Sing
Company: ACE
USERID generated: ACEZKUS

Answer 1

Hello,
It's good idea to look for dba_dependencies. But, i would recomend to use TOAD or OEM consol for viewing the code, because its very easy. I know that many users says to use the data dictionary for this purpose but it's oky for learning purpose but in real time it's worth to use data dictionary when tools are available for making work easy, faster.