Bạn có thể giúp tôi viết một thủ tục trong Oracle để chuyển dữ liệu từ một bảng vào một tệp CSV không?

Tôi nghĩ rằng có nhiều cách tốt hơn để thực hiện điều này trên Oracle 10g / 11g, nhưng điều này sẽ hoạt động tốt trên Oracle 9i trở lên:

CREATE OR REPLACE PROCEDURE prc_file_mult_column_generate(
p_file_dir         VARCHAR2, -- mandatory (Oracle directory name)
p_file_name     VARCHAR2, -- mandatory
p_sql_query        VARCHAR2, -- Multiple column SQL SELECT statement that needs to be executed and processed
p_delimiter     CHAR      -- column delimiter
)
AS

l_cursor_handle  INTEGER;
l_dummy              NUMBER;
l_col_cnt          INTEGER;
l_rec_tab            DBMS_SQL.DESC_TAB;
l_current_col      NUMBER(16);
l_current_line   VARCHAR2(2047);
l_column_value   VARCHAR2(300);

l_file_handle      UTL_FILE.FILE_TYPE;
l_print_text       VARCHAR2(100);
l_record_count   NUMBER(16) := 0;

BEGIN

   /* Open file for append*/
   l_file_handle := UTL_FILE.FOPEN(p_file_dir, p_file_name, 'a', 2047); --Append Mode, 2047 chars per line max, possibly increasable

   l_cursor_handle := DBMS_SQL.OPEN_CURSOR;
   DBMS_SQL.PARSE(l_cursor_handle, p_sql_query, DBMS_SQL.native);
   l_dummy := DBMS_SQL.EXECUTE(l_cursor_handle);

   /* Output column names and define them for latter retrieval of data */
   DBMS_SQL.DESCRIBE_COLUMNS(l_cursor_handle, l_col_cnt, l_rec_tab); -- get column names

   /* Append to file column headers */
   l_current_col := l_rec_tab.FIRST;
   IF (l_current_col IS NOT NULL) THEN
      LOOP
         DBMS_SQL.DEFINE_COLUMN(l_cursor_handle, l_current_col, l_column_value, 300);
         l_print_text := l_rec_tab(l_current_col).col_name || p_delimiter;
         UTL_FILE.PUT (l_file_handle, l_print_text);
         l_current_col := l_rec_tab.NEXT(l_current_col);
         EXIT WHEN (l_current_col IS NULL);
      END LOOP;
   END IF;
   UTL_FILE.PUT_LINE (l_file_handle,' ');

   /* Append data for each row */
   LOOP
      EXIT WHEN DBMS_SQL.FETCH_ROWS(l_cursor_handle) = 0; -- no more rows to be fetched

      l_current_line := '';
      /* Append data for each column */
      FOR l_current_col IN 1..l_col_cnt LOOP
         DBMS_SQL.COLUMN_VALUE (l_cursor_handle, l_current_col, l_column_value);
         l_print_text := l_column_value || p_delimiter;

         l_current_line := l_current_line || l_column_value || p_delimiter;
      END LOOP;
      l_record_count := l_record_count + 1;
      UTL_FILE.PUT_LINE (l_file_handle, l_current_line);
   END LOOP;

   UTL_FILE.FCLOSE (l_file_handle);
   DBMS_SQL.CLOSE_CURSOR(l_cursor_handle);

EXCEPTION
   WHEN OTHERS THEN

   -- Release resources
   IF DBMS_SQL.IS_OPEN(l_cursor_handle) THEN
      DBMS_SQL.CLOSE_CURSOR(l_cursor_handle);
   END IF;

   IF UTL_FILE.IS_OPEN (l_file_handle) THEN
      UTL_FILE.FCLOSE (l_file_handle);
   END IF;

   --RAISE ;
   DBMS_OUTPUT.PUT_LINE(DBMS_UTILITY.format_error_stack);

END;
/