Update column value by 1 in Oracle table conditionally - sql

Question

I have an Oracle table with 4 columns (Name, Phone, Email, Count).
If the user is updating value of Name column, then I need to increment Count column value by 1.
If the user is updating values other than Name column, then I don't need to increment Count column value by 1.
Initially, when the record is inserted, Count should be 0. And every time when Name column is updated, the Count should be incremented by 1 (like 1, 2, 3 .....).
How we can achieve this? I am very new to databases.
Thanks a lot for your help.

Answer 1

You can do that in an update and insert trigger or in your program. The later however requires all possible programs to cooperate. The former (triggers) is black art.
A program can do it like this:
UPDATE Person SET Count=Count+1, Phone='123' WHERE name=`csr` and Phone <> '123';
This will update one or no record (i.e. if phone was already 123 it will do nothing).
BTW: there is no nice solution to insert it if it was missing.
Hmm, you changed your question, updating the Name is problematic if you do not have another primary key, is that really what you want?

Answer 2

If you are looking at plsql procedure, then you can use this method,
I am using 3 input variables,
1.) column name to edit
2.) old value
3.) New value to be updated
SQL> create or replace procedure updateval (colname varchar2,oldval varchar2,newval varchar2) is
2 l_prop varchar2(10);
3 l_newval varchar2(10);
4 l_old_val varchar2(10);
5 begin
6 l_prop:=colname;
7 l_newval:=newval;
8 l_old_val:=oldval;
9 IF (upper(l_prop)='NAME') THEN
10 update TESTING123 set name=l_newval,count=count+1 where name=l_old_val;
11 elsif (upper(l_prop)='PHONE') THEN
12 update TESTING123 set PHONE=l_newval ,count=count+1where PHONE=l_old_val;
13 elsif (upper(l_prop)='EMAIL') THEN
14 update TESTING123 set EMAIL=l_newval ,count=count+1 where EMAIL=l_old_val;
15 END IF;
16 end;
17 /
Procedure created.
SQL>
SQL> select * from testing123;
NAME PHONE EMAIL COUNT
---------- ---------- ---------- ----------
abc1 12345 ABC#a.COM 1
xyz 3435 xyz#a.COM 0
SQL> exec updateval ('NAME','abc1','newabc1');
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> select * from testing123;
NAME PHONE EMAIL COUNT
---------- ---------- ---------- ----------
newabc1 12345 ABC#a.COM 2
xyz 3435 xyz#a.COM 0