Query Column List convert to CLOB

Question

Hi,
we need to print the data by using UTL_FILE from the dynamically constructing sql query with pivot column (It is having more than 1000 column).
But this query contains 1008 columns but it throwing error maxmimum number of columns in a table or views 1000.
Query
Select col1,col2,col3,clo4,col5,col6,col7,col8 ,Pivot columns 1 to 1000 from tab1
Each and every column data having more than 3500.
Please share your idea ?
1.is it possoble to concatenate all the columns and write into file using utl_file.
2.How to convert the rows as clob column
3.Each and every row should contains more than 32767.
Regards,
Sudhakar P.

Answer 1

Sudhakar P wrote:
Hi,
we need to print the data by using UTL_FILE from the dynamically constructing sql query with pivot column (It is having more than 1000 column).
But this query contains 1008 columns but it throwing error maxmimum number of columns in a table or views 1000.Can't overcome Oracle's internal limits.
Each and every column data having more than 3500.More than 3500 what?
1.is it possoble to concatenate all the columns and write into file using utl_file.Yes.
2.How to convert the rows as clob columnUse built in LOB functionality, such as provided in the DBMS_LOB package for example.
3.Each and every row should contains more than 32767.You would have to use CLOB's to store more than 4000 characters in SQL. 32767 is the limit in PL/SQL for VARCHAR2.
If it's dynamic, then you're going to have to pretty much use the DBMS_SQL package to construct things (11g allows the use of CLOB with EXECUTE IMMEDIATE for dynamic statements but it's still not ideal to get the data back if you don't know the output structure).
Here's an example from my standard library for writing out dynamic SQL output to a CSV file, which would probably be a good starting point...
As sys user:
CREATE OR REPLACE DIRECTORY TEST_DIR AS '\tmp\myfiles'
GRANT READ, WRITE ON DIRECTORY TEST_DIR TO myuser
/As myuser:
CREATE OR REPLACE PROCEDURE run_query(p_sql IN VARCHAR2
                                     ,p_dir IN VARCHAR2
                                     ,p_header_file IN VARCHAR2
                                     ,p_data_file IN VARCHAR2 := NULL) IS
  v_finaltxt  VARCHAR2(4000);
  v_v_val     VARCHAR2(4000);
  v_n_val     NUMBER;
  v_d_val     DATE;
  v_ret       NUMBER;
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num     NUMBER;
  v_fh        UTL_FILE.FILE_TYPE;
  v_samefile  BOOLEAN := (NVL(p_data_file,p_header_file) = p_header_file);
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, p_sql, DBMS_SQL.NATIVE);
  d := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);
  FOR j in 1..col_cnt
  LOOP
    CASE rec_tab(j).col_type
      WHEN 1 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
      WHEN 2 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_n_val);
      WHEN 12 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_d_val);
    ELSE
      DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
    END CASE;
  END LOOP;
  -- This part outputs the HEADER
  v_fh := UTL_FILE.FOPEN(upper(p_dir),p_header_file,'w',32767);
  FOR j in 1..col_cnt
  LOOP
    v_finaltxt := ltrim(v_finaltxt||','||lower(rec_tab(j).col_name),',');
  END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
  UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  IF NOT v_samefile THEN
    UTL_FILE.FCLOSE(v_fh);
  END IF;
  -- This part outputs the DATA
  IF NOT v_samefile THEN
    v_fh := UTL_FILE.FOPEN(upper(p_dir),p_data_file,'w',32767);
  END IF;
  LOOP
    v_ret := DBMS_SQL.FETCH_ROWS(c);
    EXIT WHEN v_ret = 0;
    v_finaltxt := NULL;
    FOR j in 1..col_cnt
    LOOP
      CASE rec_tab(j).col_type
        WHEN 1 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_v_val);
                    v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
        WHEN 2 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_n_val);
                    v_finaltxt := ltrim(v_finaltxt||','||v_n_val,',');
        WHEN 12 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_d_val);
                    v_finaltxt := ltrim(v_finaltxt||','||to_char(v_d_val,'DD/MM/YYYY HH24:MI:SS'),',');
      ELSE
        v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
      END CASE;
    END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
    UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  END LOOP;
  UTL_FILE.FCLOSE(v_fh);
  DBMS_SQL.CLOSE_CURSOR(c);
END;This allows for the header row and the data to be written to seperate files if required.
e.g.
SQL> exec run_query('select * from emp','TEST_DIR','output.txt');
PL/SQL procedure successfully completed.Output.txt file contains:
empno,ename,job,mgr,hiredate,sal,comm,deptno
7369,"SMITH","CLERK",7902,17/12/1980 00:00:00,800,,20
7499,"ALLEN","SALESMAN",7698,20/02/1981 00:00:00,1600,300,30
7521,"WARD","SALESMAN",7698,22/02/1981 00:00:00,1250,500,30
7566,"JONES","MANAGER",7839,02/04/1981 00:00:00,2975,,20
7654,"MARTIN","SALESMAN",7698,28/09/1981 00:00:00,1250,1400,30
7698,"BLAKE","MANAGER",7839,01/05/1981 00:00:00,2850,,30
7782,"CLARK","MANAGER",7839,09/06/1981 00:00:00,2450,,10
7788,"SCOTT","ANALYST",7566,19/04/1987 00:00:00,3000,,20
7839,"KING","PRESIDENT",,17/11/1981 00:00:00,5000,,10
7844,"TURNER","SALESMAN",7698,08/09/1981 00:00:00,1500,0,30
7876,"ADAMS","CLERK",7788,23/05/1987 00:00:00,1100,,20
7900,"JAMES","CLERK",7698,03/12/1981 00:00:00,950,,30
7902,"FORD","ANALYST",7566,03/12/1981 00:00:00,3000,,20
7934,"MILLER","CLERK",7782,23/01/1982 00:00:00,1300,,10The procedure allows for the header and data to go to seperate files if required. Just specifying the "header" filename will put the header and data in the one file.
Adapt to output different datatypes and styles are required.