How do we print characters line by line and save it to csv or text file in PLSQL - sql

Question

DECLARE
V_NUMBER NUMBER :=23;
BEGIN
LOOP
V_NUMBER:=V_NUMBER+1;
EXIT WHEN V_NUMBER:=25;
--Some kind of function to be applied for printing and nesting lines into CSV or TEXT file.
END LOOP;
COMMIT;
END;

Answer 1

Scripting an Oracle SQL Query for Creating a CSV or Text Typed File Output
Consider running this from a SQL Plus session and use the SPOOL command. All output of the SQL command that follows will be written to the file name you specify.
If you need to append your results each successive time the SQL commands are run, then an OS level command would work appropriately when invoking this sqlplus executable block of PL/SQL:
Where the file name of this script is: "sample_csv_out.sql"
DECLARE
v_total_columns constant number:= 3; -- Number of columns queried
v_column_counter number;
v_csv_record varchar2(1000);
c_csv_column_format constant varchar2(15):=
'<<COLUMN1_VAL>>,<<COLUMN2_VAL>>,<<COLUMN3_VAL>>';
cursor result_cur is
SELECT column1, column2, column3
FROM tablea
WHERE column1 = ... ;
BEGIN
v_csv_record:= 'COLUMN1,COLUMN2,COLUMN3';
dbms_output.put_line (v_csv_record);
FOR i in result_cur LOOP
v_csv_record:= replace(c_csv_column_format, '<<COLUMN1_VAL>>', i.column1);
v_csv_record:= replace(v_csv_record, '<<COLUMN2_VAL>>', i.column2);
v_csv_record:= replace(c_csv_record, '<<COLUMN3_VAL>>', i.column3);
dbms_output.put_line(v_csv_record);
END LOOP;
END;
So, for example in a WINDOWS O/S environment, the call to append the output to a specific file name would be:
C:\> sqlplus sample_csv_out.sql >> mycsv_out.csv
The >> notation instructs the operating system to pipe the output of running sample_csv_out.sql via a sqlplus session.
The command DBMS_OUTPUT does the rest. If you need more details, see more Oracle documentation on DBMS_OUTPUT.
COMMENTS: I chose the RECORD STRING TEMPLATE approach to make this script a little more flexible and reusable. I recommend to keep any data manipulation logic within the CURSOR statement. Often when the two are mixed, it gets harder to debug any typos in syntax within a long string of values.
The construction of an output record was also designed to reduce typos, mistakes and frustration... if there are more than 3 columns in your own scripts, adding another element to the output string is mostly a cut-and-paste operation. Likewise with the "header" row (column titles).

Answer 2

You can read and write files in PL/SQL using the UTIL_FILE package
http://docs.oracle.com/cd/B19306_01/appdev.102/b14258/u_file.htm