Upload data from a flat file to Oracle tables

This article provides 10 practical examples on how to upload data from a flat file to Oracle tables.

Input data file for SQL*Loader

This is the input text file that contains the data that needs to be loaded into an oracle table. Each and every records needs to be in a separate line, and the column values should be delimited by some common delimiter character. For some of the examples mentioned below, we’ll use the following employee.txt file to upload the data to the employee table.

$ cat employee.txt
100,Thomas,Sales,5000
200,Jason,Technology,5500
300,Mayla,Technology,7000
400,Nisha,Marketing,9500
500,Randy,Technology,6000
501,Ritu,Accounting,5400

SQL*Loader Control File

This contains the instructions to the sqlldr utility. This tells sqlldr the location of the input file, the format of the input file, and other optional meta data information required by the sqlldr to upload the data into oracle tables.

$ cat example1.ctl
load data
 infile '/home/ramesh/employee.txt'
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )

The above control file indicates the following:

  • infile – Indicates the location of the input data file
  • into table – Indicates the table name where this data should be inserted
  • fields terminated by – Indicates the delimiter that is used in the input file to separate the fields
  • ( id, name, dept, salary ) – Lists the name of the column names in the table into which the data should be uploaded

1. Basic Upload Example Using SQL*Loader

First, create the employee table as shown below.

SQL> create table employee
(
  id integer,
  name varchar2(10),
  dept varchar2(15),
  salary integer,
  hiredon date
)

Next create the control file that explains what needs to be upload and where.

$ cat sqlldr-add-new.ctl
load data
 infile '/home/ramesh/employee.txt'
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )

Note: If you have the values inside the data file enclosed with double quote, use this in your control file: fields terminated by “,” optionally enclosed by ‘”‘

Note: If you don’t have the table created, you’ll get the following error message:

SQL*Loader-941: Error during describe of table EMPLOYEE
ORA-04043: object EMPLOYEE does not exist

You can pass the userid and password to the sqlldr command using any one of the following format. As you see below, both of these will prompt you for control file location, as it was not given in the command line.

$ sqlldr scott/tiger

(or)

$ sqlldr userid=scott/tiger
control =
SQL*Loader-287: No control file name specified.

Execute the sqlldr command to upload these new record to the empty table by specifying both uid/pwd and the control file location as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-add-new.ctl
Commit point reached - logical record count 5

Verify the the records are created in the database

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- -------
       100 Thomas     Sales                 5000
       200 Jason      Technology            5500
       300 Mayla      Technology            7000
       400 Nisha      Marketing             9500
       500 Randy      Technology            6000

This will create the output log file in the same name as the data file, but with the .log extension (instead of .ctl). Partial output shown below.

$ cat sqlldr-add-new.log

Control File:   /home/ramesh/sqlldr-add-new.ctl
Data File:      /home/ramesh/employee.txt

Table EMPLOYEE:
  5 Rows successfully loaded.
  0 Rows not loaded due to data errors.
  0 Rows not loaded because all WHEN clauses were failed.
  0 Rows not loaded because all fields were null.

Elapsed time was:     00:00:00.04
CPU time was:         00:00:00.00

If you are new to Oracle database, and like to install it, follow this Oracle 11g installation guide.

2. Inserting Additional Records

Let us say you want to add two new employees to the employee table from the following newemployee.txt file.

$ vi newemployee.txt
600,Ritu,Accounting,5400
700,Jessica,Marketing,7800

If you create a similar control file like the previous example, you might get the following error message.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-add-more.ctl
SQL*Loader-601: For INSERT option, table must be empty.  Error on table EMPLOYEE

The above indicates that the table should be empty before you can upload data using sql*loader.

If you like to insert more data to the tables without having to delete the existing rows, use the “append’ command as shown in the following control file.

$ vi sqlldr-append-more.ctl
load data
 infile '/home/ramesh/newemployee.txt'
 append
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )

Now, if you do sqlldr this will append the data.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-append-more.ctl
Commit point reached - logical record count 2

Verify that the records are appended successfully

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- -------
       100 Thomas     Sales                 5000
       200 Jason      Technology            5500
       300 Mayla      Technology            7000
       400 Nisha      Marketing             9500
       500 Randy      Technology            6000
       600 Ritu       Accounting            5400
       700 Jessica    Marketing             7800

3. Data inside the Control File using BEGINDATA

You can also specify the data directly inside the control file itself using BEGINDATA keyword. i.e Anything that comes after BEGINDATA will be treated as data to be uploaded to the table as shown below.

$ cat sqlldr-add-new-with-data.ctl
load data
 infile *
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )
begindata
100,Thomas,Sales,5000
200,Jason,Technology,5500
300,Mayla,Technology,7000
400,Nisha,Marketing,9500
500,Randy,Technology,6000

Note: The infile will say ‘*’ in this case, as there is no input data file name for this example.

Execute sqlldr to upload the data from the control file.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-add-new-with-data.ctl

4. Date format and Different Delimiter

This example shows how to specify a date format in the control file and how to handle different delimiters in a data file

The following example has different delimiters ($ after name, ^ after department).

$ cat employee-date.txt
100,Thomas$Sales^5000,31-JAN-2008
200,Jason$Technology^5500,01-Feb-2005
300,Mayla$Technology^7000,10-Aug-2000
400,Nisha$Marketing^9500,12-Dec-2011
500,Randy$Technology^6000,01-JAN-2007

Create the following control file and indicate the field delimiters for each and every field using “terminated by” as shown below.

$ cat sqlldr-date.ctl
load data
 infile '/home/ramesh/employee-date.txt'
 into table employee
 fields terminated by ","
 ( id, name terminated by "$", dept terminated by "^", salary, hiredon DATE "dd-mon-yyyy" )

Load the data using sqlldr as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-date.ctl

Verify that the data got loaded properly as shown below.

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
       100 Thomas     Sales                 5000 31-JAN-08
       200 Jason      Technology            5500 01-FEB-05
       300 Mayla      Technology            7000 10-AUG-00
       400 Nisha      Marketing             9500 12-DEC-11
       500 Randy      Technology            6000 01-JAN-07

5. Fixed Length Data Upload

If you have a data file without data that are fixed length (i.e without any delimiter), you can use this example to upload this data.

For this example, let us use the following file which has data that are of fixed length. For example, 1st three characters are always employee number, Next 5 characters are always employee name, etc.

$ cat employee-fixed.txt
200JasonTechnology5500
300MaylaTechnology7000
400NishaTechnology9500
500RandyTechnology6000

Create the following control file, where you specific the position of each and every field as shown below usig the “Position(start:end)” syntax.

$ cat sqlldr-fixed.ctl
load data
 infile '/home/ramesh/employee-fixed.txt'
 into table employee
 fields terminated by ","
 ( id position(1:3), name position(4:8), dept position(9:18), salary position(19:22) )

Load this fixed length data using the sqlldr as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-fixed.ctl

Verify that the data got loaded.

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
       200 Jason      Technology            5500
       300 Mayla      Technology            7000
       400 Nisha      Technology            9500
       500 Randy      Technology            6000

6. Change the data during upload

You can also massage the data and change it during upload based on certain rules.

In the following control file:

  • id is incremented by 999 before uploading. i.e if the emp id is 100 in the data file, it will be loaded as 1099
  • Convert the name to upper case and load it. This uses the upper function.
  • If the department contains the value “Technology” change it to “Techies”. This uses decode function
$ cat sqlldr-change-data.ctl
load data
 infile '/home/ramesh/employee.txt'
 into table employee
 fields terminated by ","
 ( id ":id+999",
   name "upper(:name)",
   dept  "decode(:dept,'Technology','Techies', :dept)",
   salary
  )

Load the data using this control file which will massage the data before uploading it.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-change-data.ctl

Verify that the data got changed while loading as per our rules.

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
      1099 THOMAS     Sales                 5000
      1199 JASON      Techies               5500
      1299 MAYLA      Techies               7000
      1399 NISHA      Marketing             9500
      1499 RANDY      Techies               6000

7. Load data from multiple files

To load data from multiple files, you just have to specify multiple infile in the control file.

The following control file loads data from two different data files (employee.txt and newemployee.txt) to the employee table.

$ sqlldr-add-multiple.ctl
load data
 infile '/home/ramesh/employee.txt'
 infile '/home/ramesh/newemployee.txt'
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )

Load the data using this control file which will upload data from multiple data files as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-add-multiple.ctl
Commit point reached - logical record count 5
Commit point reached - logical record count 7

8. Load data to Multiple Tables

Create another table called bonus which will have employee id and bonus columns.

create table bonus
  ( id integer,
    bonus integer
  );

Create the employee-bonus.txt data file that contains the fields: id, name, department, salary, bonus

$ cat employee-bonus.txt
100 Thomas Sales      5000 1000
200 Jason  Technology 5500 2000
300 Mayla  Technology 7000 2000
400 Nisha  Marketing  9500 1000
500 Randy  Technology 6000 3000

Create the control file as shown below, which will upload the data from the above file to two different tables. As shown below, you should have two “into table” commands, and specify the position of the data which needs to be used to upload the data to that column.

$ cat sqlldr-multiple-tables.ctl
load data
 infile '/home/ramesh/employee-bonus.txt'
 into table employee
 ( id position(1:3),
   name position(5:10),
   dept position(12:21),
   salary position(23:26))
 into table bonus
 ( id position(1:3),
   bonus position(28:31))

Load the data to multiple tables using this control file as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-multiple-tables.ctl

Verify that the data got loaded to multiple tables successfully.

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
       100 Thomas     Sales                 5000
       200 Jason      Technology            5500
       300 Mayla      Technology            7000
       400 Nisha      Marketing             9500
       500 Randy      Technology            6000

SQL> select * from bonus;

        ID      BONUS
---------- ----------
       100       1000
       200       2000
       300       2000
       400       1000
       500       3000

9. Handling Bad (Rejected) Records

In the following example, we have two bad records. Employee id 300 and 500 has salary column which is not numeric.

$ cat employee-bad.txt
100,Thomas,Sales,5000
200,Jason,Technology,5500
300,Mayla,Technology,7K
400,Nisha,Marketing,9500
500,Randy,Technology,6K

Use the following control file for this example.

$ cat sqlldr-bad.ctl
load data
 infile '/home/ramesh/employee-bad.txt'
 into table employee
 fields terminated by ","
 ( id, name, dept, salary )

Load the data (including the invalid records) using this control file as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-bad.ctl
Commit point reached - logical record count 5

As you see from the abvoe output, it still says “logical record count 5″, but you should check the log files to see if it has rejected any records.

The log file indicates that 2 records are rejected as shown below:

Control File:   /home/ramesh/sqlldr-bad.ctl
Data File:      /home/ramesh/employee-bad.txt
  Bad File:     /home/ramesh/employee-bad.bad
  Discard File:  none specified

Table EMPLOYEE:
  3 Rows successfully loaded.
  2 Rows not loaded due to data errors.

By default the rejected records are stored in a file that has the same name as the data file (but with .bad extension)

$ cat employee-bad.bad
300,Mayla,Technology,7K
500,Randy,Technology,6K

As you see below, the employee table has only 3 records (as 2 of them were rejected).

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
       100 Thomas     Sales                 5000
       200 Jason      Technology            5500
       400 Nisha      Marketing             9500

10. Load Specific Rows from a datafile

If you want to load only a specific records from a data file use the WHEN in the control file.

Add the line “when” next to “into table” line. In the following control file, the when clause indicates that it will load only the records that have dept as “Technology”.

$ cat sqlldr-when.ctl
load data
 infile '/home/ramesh/employee.txt'
 into table employee
 when dept = 'Technology'
 fields terminated by ","
 ( id, name, dept, salary )

Load the selective data (only the “Technology” records) using this control file as shown below.

$ sqlldr scott/tiger control=/home/ramesh/sqlldr-when.ctl
Commit point reached - logical record count 5

As you see from the above output, it still says “logical record count 5″, but you should check the log files to see how many records were loaded, and how many records were discarded because it didn’t match the when condition.

The following from the log file shows that 5 records were read, and 2 of them were discarded as it didn’t match the when condition.

Discard File:  none specified
Total logical records read:             5
Total logical records discarded:        2

Verify that only the selective records were loaded into the table.

SQL> select * from employee;

        ID NAME       DEPT                SALARY HIREDON
---------- ---------- --------------- ---------- ---------
       200 Jason      Technology            5500
       300 Mayla      Technology            7000
       500 Randy      Technology            6000

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