Export Table data to CSV file

CREATE OR REPLACE PROCEDURE dump_table_to_csv (
p_tname IN VARCHAR2,
p_dir IN VARCHAR2,
p_filename IN VARCHAR2
)
IS
l_output UTL_FILE.file_type;
l_thecursor INTEGER DEFAULT DBMS_SQL.open_cursor;
l_columnvalue VARCHAR2 (4000);
l_status INTEGER;
l_query VARCHAR2 (1000) DEFAULT 'SELECT * FROM ' p_tname;
l_colcnt NUMBER := 0;
l_separator VARCHAR2 (1);
l_desctbl DBMS_SQL.desc_tab;
BEGIN
l_output := UTL_FILE.fopen (p_dir, p_filename, 'w');
EXECUTE IMMEDIATE 'ALTER SESSION SET nls_date_format=''dd-mon-yyyy hh24:mi:ss''';
DBMS_SQL.parse (l_thecursor, l_query, DBMS_SQL.native);
DBMS_SQL.describe_columns (l_thecursor, l_colcnt, l_desctbl);
FOR i IN 1 .. l_colcnt
LOOP
UTL_FILE.put (l_output,
l_separator '"' l_desctbl (i).col_name '"'
);
DBMS_SQL.define_column (l_thecursor, i, l_columnvalue, 4000);
l_separator := ',';
END LOOP;
UTL_FILE.new_line (l_output);
l_status := DBMS_SQL.EXECUTE (l_thecursor);
WHILE (DBMS_SQL.fetch_rows (l_thecursor) > 0)
LOOP
l_separator := '';
FOR i IN 1 .. l_colcnt
LOOP
DBMS_SQL.COLUMN_VALUE (l_thecursor, i, l_columnvalue);
UTL_FILE.put (l_output, l_separator l_columnvalue);
l_separator := ',';
END LOOP;
UTL_FILE.new_line (l_output);
END LOOP;
DBMS_SQL.close_cursor (l_thecursor);
UTL_FILE.fclose (l_output);
EXECUTE IMMEDIATE 'ALTER SESSION SET nls_date_format=''dd-MON-yy'' ';
EXCEPTION
WHEN OTHERS
THEN
EXECUTE IMMEDIATE 'ALTER SESSION SET nls_date_format=''dd-MON-yy'' ';
RAISE;
END;
/