Sqlloader control file when clause

Question

Problem 1
Lets say, I have a table x with (f1 number(2), f2 varchar(14), f3 Number(1))
datafile1
10,ls
22,st
45,tanveer
77,cool
1,not cool
requirement is to insert the first 2 columns in f1 and f2 and insert 0 in f3 only
if f2 == tanveer
Problem 2
Table is y (f4 number (2), f5 varchar (16))
datafile2
ls,xxxx
tanveer,yyyy
cool,zzzz
not cool, mmmm
given the value of the first coloumn I would like to query table x
and find the corresponding value of f1 insert it to table y's column f4
and associated string to f5.
Please let me know how to write the control files for sqlloader.

Answer 1

Problem 1:
-- control file:
LOAD DATA
INFILE 'DATAFILE1.DAT'
APPEND
INTO TABLE x
FIELDS TERMINATED BY ','
TRAILING NULLCOLS
(f1, f2,
f3 "DECODE (:f2, 'tanveer', 0, NULL)")
Problem 2:
Create another table z,
load the data into z,
insert into y selecting
from join of x and z:
-- create staging table:
CREATE TABLE z
  (f6 VARCHAR2 (14),
   f7 VARCHAR2 (16));
-- control file:
LOAD DATA
INFILE 'DATFILE2.DAT'
APPEND
INTO TABLE z
FIELDS TERMINATED BY ','
TRAILING NULLCOLS
(f6, f7)
-- insert:
INSERT INTO y (f4, f5)
SELECT x.f1, z.f7
FROM   x, z
WHERE  z.f6 = x.f2;