While developing Oracle PL/SQL code, sometimes one needs to debug via the old way, using DBMS_OUTPUT.PUT_LINE or inserting data into a table for a later inspection.
But when working with cursors, this is not an easy task, specially if one does not know the real output of the cursor when using dynamic SQL or simply because the cost of writing a specific output for each cursor one needs to evaluate is too high.
In order to aid this task, here’s a procedure that will print out the result of any cursor. By default, it will print the first 10 rows, but to print the entire result, just call the PRINT_CURSOR procedure with the v_maxRows = 0.
create or replace
PROCEDURE PRINT_CURSOR (
p_refcursor IN OUT SYS_REFCURSOR, v_maxRows IN NUMBER default 10 )
AS
v_desc DBMS_SQL.DESC_TAB;
v_cols BINARY_INTEGER;
v_cursor BINARY_INTEGER;
v_varchar2 VARCHAR2(4000);
v_number NUMBER;
v_date DATE;
v_data VARCHAR2(32767);
v_curRow NUMBER;
BEGIN
/* Convert refcursor "parameter" to DBMS_SQL cursor... */
v_cursor := DBMS_SQL.TO_CURSOR_NUMBER(p_refcursor);
/* Describe the cursor... */
DBMS_SQL.DESCRIBE_COLUMNS(v_cursor, v_cols, v_desc);
/* Define columns to be fetched. We're only using V2, NUM, DATE for example... */
FOR i IN 1 .. v_cols
LOOP
IF v_desc(i).col_type = 2 THEN
DBMS_SQL.DEFINE_COLUMN(v_cursor, i, v_number);
ELSIF v_desc(i).col_type = 12 THEN
DBMS_SQL.DEFINE_COLUMN(v_cursor, i, v_date);
ELSE
DBMS_SQL.DEFINE_COLUMN(v_cursor, i, v_varchar2, 4000);
END IF;
END LOOP;
/* Now output the data, starting with header... */
DBMS_OUTPUT.NEW_LINE;
FOR i IN 1 .. v_cols
LOOP
v_data := v_data ||
CASE v_desc(i).col_type
WHEN 2 THEN
LPAD(v_desc(i).col_name, v_desc(i).col_max_len+1)
WHEN 12 THEN
RPAD(v_desc(i).col_name, 22)
ELSE
RPAD(v_desc(i).col_name, v_desc(i).col_max_len+1)
END || ' ';
END LOOP;
DBMS_OUTPUT.PUT_LINE(v_data);
v_data := NULL;
FOR i IN 1 .. v_cols
LOOP
v_data := v_data ||
CASE v_desc(i).col_type
WHEN 2 THEN
LPAD('-', v_desc(i).col_max_len+1, '-')
WHEN 12 THEN
RPAD('-', 22, '-')
ELSE
RPAD('-', v_desc(i).col_max_len+1, '-')
END || ' ';
END LOOP;
DBMS_OUTPUT.PUT_LINE(v_data);
/* Fetch all data... */
v_curRow := v_maxRows;
WHILE DBMS_SQL.FETCH_ROWS(v_cursor) > 0
LOOP
v_data := NULL;
FOR i IN 1 .. v_cols
LOOP
IF v_desc(i).col_type = 2 THEN
DBMS_SQL.COLUMN_VALUE(v_cursor, i, v_number);
v_data := v_data || LPAD(v_number, v_desc(i).col_max_len+1) || ' ';
ELSIF v_desc(i).col_type = 12 THEN
DBMS_SQL.COLUMN_VALUE(v_cursor, i, v_date);
v_data := v_data || RPAD(v_date, 22) || ' ';
ELSE
DBMS_SQL.COLUMN_VALUE(v_cursor, i, v_varchar2);
v_data := v_data || RPAD(v_varchar2, v_desc(i).col_max_len+1) || ' ';
END IF;
END LOOP;
DBMS_OUTPUT.PUT_LINE(v_data);
if v_maxRows <> 0 then
v_curRow := v_curRow - 1;
exit when 0 = v_curRow;
end if;
END LOOP;
DBMS_SQL.CLOSE_CURSOR(v_cursor);
END;
