Tuesday, August 26, 2014

Error PLS-00302: Component must be declared

Error PLS-00302: Component must be declared

select xx.maxno from dual

Where 'maxno' is the function in other schema 'XX'

and we are getting the error PLS-00302.

There are many reasons for this error :-

One can be 'maxno' exists in the current schema
or

SELECT * from all_objects where object_name like 'XX'


If yes this error will come ...so either you have to change the schema name or change the duplicate
object name in your current schema.Hope it will solve your problem...

Sunday, July 13, 2014

Error Frm-40505 :-Unable to perform query..

Error Frm-40505 :-Unable to perform query..

To check this error Press Ctrl+Shift+E. Mostly it is non-database item defined as database..or database item not defined but used in form.

Wednesday, June 18, 2014

How to write format trigger on report based on page number

we can decide what to hide and display in report based on the page number:-
function F_4FormatTrigger return boolean is
 pagenum   number;
begin
  srw.get_page_num(pagenum);
  if pagenum = 1  then
    return (TRUE);
  else
    return (FALSE);
  end if;

end;

Sunday, May 18, 2014

Oracle query optimization tips

Query optimization tips :-

1.Rewrite complex subqueries with temporary tables.

2.Use minus instead of EXISTS subqueries

3.Use SQL analytic functions

4.Re-write NOT EXISTS and NOT EXISTS subqueries as outer joins

5. Index all the comparing columns in query

6.Avoid the use of NOT IN or HAVING

7.Avoid the LIKE predicate

8.Use decode and case

9.Always use table aliases when referencing columns

10.Never mix data types

comparision between regexp_like and like statements

Search using like is always faster than the regexp_like.
REGEXP_LIKE is similar to the LIKE condition, except REGEXP_LIKE performs regular expression matching instead of the simple pattern matching performed by LIKE.
This condition evaluates strings using characters as defined by the input character set.

LIKE syntax for pattern is simple and supports a small set of wildcards,
but does not support the full regular expression syntax.

Whereas the equality operator (=) exactly matches one character value to another, the LIKE conditions match a portion of one character value to another by searching the first value for the pattern specified by the second.
LIKE calculates strings using characters as defined by the input character set

Wednesday, April 2, 2014

how to get the first_date and last_date of the months between the given time period

how to get the first_date and last_date of the months between the given time period

We have a start date and end date given as an input .We have to calculate the number of months and start date ,end date of each month.
The following query is used to calculate the above requirement:-

SELECT ADD_MONTHS(TRUNC(TO_DATE('02-Mar-2014', 'DD-MON-YYYY'), 'MON'), ROWNUM - 1) start_date
,last_day(ADD_MONTHS(TRUNC(TO_DATE('02-Mar-2014', 'DD-MON-YYYY'), 'MON'), ROWNUM - 1) ) end_date
FROM   DUAL
CONNECT BY ADD_MONTHS(TRUNC(TO_DATE('02-Mar-2014', 'DD-MON-YYYY'), 'MON'), ROWNUM - 1)
    <= TRUNC(TO_DATE('29-Jun-2014', 'DD-MON-YYYY'), 'MON')


and the output will be like:-
start_date end_date

01/03/2014|31/03/2014
01/04/2014|30/04/2014
01/05/2014|31/05/2014
01/06/2014|30/06/2014

Tuesday, March 4, 2014

How to display bar-code format value in Oracle reports?

Sometimes some key fields are required to be displayed in a bar-code format. One thing we should have the font bar code 39 .. concatenate the value to be displayed as bar code with '*' .
for example I want to display employee_code as bar code format then in a formula column write '*'||employee_code||'*' and assign this value to the bar code field. Then in the output we can see bar code formatted field value!!

Sunday, February 23, 2014

How to calculate working days for an organization , if the organization works for only a particular number of week in a month

How to calculate working days for an organization , if the organization works for only a particular number of week in a month:-


We will create a function which will take current date of calendar as input and check if this input date's week is same as the one which is required.If yes then we will return '1' else
we will return '0'.

we are removing saturday and sunday as weekends and also we are removing the week with minimum number of working days and then again re-numbering the weeks as per number of days .

IS_DEPARTMENT_WORKING(V_DATE NUMBER,wnum number) RETURN NUMBER IS

cursor c_rec is Select CNT,week_of_month,row_number() over (order by count(*) desc,week_of_month)  from
(select cnt,week_of_month,
MIN(week_of_month) KEEP (DENSE_RANK FIRST ORDER BY cnt) OVER () Lowest
from(select count(*) cnt ,week_of_month ,row_number() over (order by count(*) desc,week_of_month)
from (
select x dt,
(to_char( x+1, 'iw') - to_char(to_date('01/'||to_char(x,'mon/')||to_char(x,'yyyy'),'dd/mon/yyyy') +
1,'iw') + 1)
 Week_of_month
from
(select TRUNC(TO_DATE((V_DATE ,'YYYYMMDD'), 'MONTH')+rownum-1 x
from all_objects
where rownum <= 50
)
where to_char(x,'dy','nls_date_language=english') not in ('sat','sun')
and to_char(x,'mon')=to_char(TO_DATE((V_DATE ,'YYYYMMDD'),'mon'))
group by week_of_month) )
where ((week_of_month<>nvl(lowest,0) AND CNT <5) OR (CNT=5))
GROUP BY CNT,WEEK_OF_MONTH;

cursor c_rec2 is select x dt,
(to_char( x+1, 'iw') - to_char(to_date('01/'||to_char(x,'mon/')||to_char(x,'yyyy'),'dd/mon/yyyy') +
1,'iw') + 1)
 Week_of_month
from
(select TRUNC(TO_DATE((V_DATE ,'YYYYMMDD'), 'MONTH')+rownum-1 x
from all_objects
where rownum <= 35
)
where to_char(x,'dy','nls_date_language=english') not in ('sat','sun')
and to_char(x,'mon')=to_char(TO_DATE((V_DATE ,'YYYYMMDD'),'mon');


cnt_wdays number(5);
wnumber number(2);
worgnumber number(2);
date1 DATE;
wnumber1 number(2);
flg number(1);

BEGIN
                       
           
            open c_rec ;
            open c_rec2;
            loop
            fetch c_rec into cnt_wdays,worgnumber,wnumber;
         
           
             if wnum=wnumber then
                loop
                fetch c_rec2 into date1,wnumber1;
               
                if TO_NUMBER(TO_CHAR(date1,'YYYYMMDD'))=trunc((V_DATE ) and wnumber1=worgnumber
                then
               
                flg:=1;
                exit;
                end if;
               exit when c_rec2%notfound;
                end loop;
                     
             end if;
           
           
            exit when c_rec%notfound;
            end loop;
           
            if flg=1
            then
            RETURN 1;
            else
            return 0;
            end if;
           
END;
/



The first cursor of the function is calculating the week number and removing the smallest week and again reorganizing and renumbering the week.

The second cursor is giving all the dates removing saturday and sunday and their respective week numbers.