Filter data on GUI SQL Loader of 10g

Question

I have a 10g and using the SQL developer to import data from an excel to a table.
after right click on the table and specify the file, i have to map the column, since there is no header info in the spreadsheet.
i then came into 2 problems
1) on column with data type, it will say the data is null or invalid format.
2) only a subset of the data in the sheet is needed, so, i like to place a where clause type criteria during the import.
how to i handle these two situations? is there step by step instructions to follow on each?
thanks.

Answer 1

Your problem is most likely in decode - the return type in your expression will be character based on first search value ('null'), so it will be implicitly converted to character and then again implicitly converted to date by loading into date column. At some of this conversions you probably are loosing your time part. You can try instead use cast:
SQL> desc t
Name                                      Null?    Type
LASTWRITTEN                                        DATE
CREATEDON                                          DATE
LASTUPDATEDON                                      DATE
SQL> select * from t;
no rows selected
SQL> !cat t.ctl
LOAD DATA
INFILE *
INTO TABLE T
TRUNCATE
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' TRAILING NULLCOLS
LASTWRITTEN
"decode(:LASTWRITTEN,'null',cast(Null as date),
  to_date(:LASTWRITTEN,'YYYY-MM-DD HH24:MI:SS'))",
CREATEDON
"decode(:CREATEDON,'null',cast(Null as date),
  to_date(:CREATEDON,'YYYY-MM-DD HH24:MI:SS'))",
LASTUPDATEDON
"decode(:LASTUPDATEDON,'null',cast(Null as date),
  to_date(:LASTUPDATEDON,'DD/MM/YYYY HH24:MI:SS'))"
BEGINDATA
2007-02-15 15:10:20,null,null
null,2007-02-15 15:10:20,null
null,null,15/02/2007 15:10:20
SQL> !sqlldr userid=scott/tiger control=t.ctl log=t.log
SQL*Loader: Release 10.2.0.3.0 - Production on Fri Feb 29 00:20:07 2008
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Commit point reached - logical record count 3
SQL> select * from t;
LASTWRITTEN         CREATEDON           LASTUPDATEDON
15.02.2007 15:10:20
                    15.02.2007 15:10:20
                                        15.02.2007 15:10:20Best regards
Maxim