TO_CHAR(…, ‘D’)
to_char(nchar-clob-or-nclob) to_char(datetime-or-interval) to_char(datetime-or-interval, 'format-string') to_char(datetime-or-interval, 'format-string', 'nlsparam') to_char(number) to_char(number,'format-string') to_char(number,'format-string', 'nlsparam')
How do I get than MONDAY=1, TUESDAY=2, WEDNESDAY=3 … ?
solution1
With to_char()
alter session set nls_territory=germany; select to_char(sysdate,’DAY D’) from dual; TUESDAY 2
solution2
With decode()
The abbrivation of a day’s name (such as SUN, MON … can be retrieved with the format specifier DY. As to_char is sensitive to the actual nls setting, I use nls_date_language=english to make sure that the english abbreviation is returned, regardless of the nls setting.
select decode(to_char(sysdate, ‘FMDAY’, ‘NLS_DATE_LANGUAGE=american’),’MONDAY’, ’1′, ‘TUESDAY’, ’2′, ‘…’)) from dual;
solution3
With mod()
As a reference, I take monday Jan 1st, 1000.
select mod(trunc(sysdate)-date ’1000-01-01′,7)+1 from dual;
How do I trunc date to current monday?
trunc(date, ‘D’) or here is with my solution with 1000-01-01:
select trunc((sysdate-date ’1000-01-01′)/7)*7+date ’1000-01-01′ from dual;
thanks to jan-marcel idea, I found that one
trunc(date,’IW’) for current monday and date-trunc(date,’IW’)+1 for day number
Spelling a number
select to_char(to_date('429','J'),'Jsp') from dual;
TO_CHAR(TO_DATE('429','J
------------------------
Four Hundred Twenty-Nine
Extraction of consecutive periods (without regard to the OverLap)
kikanT
ID StaD EndD
-- ---------- ----------
10 2010-06-01 2010-06-12
10 2010-06-13 2010-06-14
10 2010-06-15 null
20 2010-06-01 2010-06-11
20 2010-06-13 2010-06-15
50 2010-11-11 2010-11-13
50 2010-11-14 2010-11-20
50 2010-12-22 2010-12-30
Summarized in consecutive periods every ID.
ID StaD EndD
-- ---------- ----------
10 2010-06-01 null
20 2010-06-01 2010-06-11
20 2010-06-13 2010-06-15
50 2010-11-11 2010-11-20
50 2010-12-22 2010-12-30
Data creation script
create table kikanT(ID,StaD,EndD) as select 10,date '2010-06-01',date '2010-06-12' from dual union select 10,date '2010-06-13',date '2010-06-14' from dual union select 10,date '2010-06-15',null from dual union select 20,date '2010-06-01',date '2010-06-11' from dual union select 20,date '2010-06-13',date '2010-06-15' from dual union select 50,date '2010-11-11',date '2010-11-13' from dual union select 50,date '2010-11-14',date '2010-11-20' from dual union select 50,date '2010-12-22',date '2010-12-30' from dual;
Solution1
How to use hierarchical queries (> 10g)
select ID,min(connect_by_root StaD) as StaD,EndD
from kikanT
where connect_by_IsLeaf = 1
connect by prior ID=ID
and prior EndD+1=StaD
group by ID,EndD
order by ID,EndD;
Solution2
Analysis of the relevant number
select ID,min(StaD) as StaD,
max(EndD) Keep(Dense_Rank Last order by EndD) as EndD
from (select ID,StaD,EndD,
sum(willSum) over(partition by ID order by StaD) as GID
from (select ID,StaD,EndD,
case when StaD = 1+Lag(EndD) over(partition by ID order by StaD)
then 0 else 1 end as willSum
from kikanT))
group by ID,GID
order by ID,GID;
Summarizes the start and end dates (or how to eleminate overlaps in dates)
TimeSheet table
StartDate EndDate
---------- ----------
2005-01-01 2005-01-03
2005-01-02 2005-01-04
2005-01-04 2005-01-05
2005-01-06 2005-01-09
2005-01-09 2005-01-09
2005-01-12 2005-01-15
2005-01-13 2005-01-14
2005-01-14 2005-01-14
2005-01-17 2005-01-17
result
StartDate EndDate
---------- ----------
2005-01-01 2005-01-05
2005-01-06 2005-01-09
2005-01-12 2005-01-15
2005-01-17 2005-01-17
Data creation script
create table TimeSheets(
StartDate Date,
EndDate Date,
primary key (StartDate));
insert into TimeSheets values(to_date('20050101','yyyymmdd'),to_date('20050103','yyyymmdd'));
insert into TimeSheets values(to_date('20050102','yyyymmdd'),to_date('20050104','yyyymmdd'));
insert into TimeSheets values(to_date('20050104','yyyymmdd'),to_date('20050105','yyyymmdd'));
insert into TimeSheets values(to_date('20050106','yyyymmdd'),to_date('20050109','yyyymmdd'));
insert into TimeSheets values(to_date('20050109','yyyymmdd'),to_date('20050109','yyyymmdd'));
insert into TimeSheets values(to_date('20050112','yyyymmdd'),to_date('20050115','yyyymmdd'));
insert into TimeSheets values(to_date('20050113','yyyymmdd'),to_date('20050114','yyyymmdd'));
insert into TimeSheets values(to_date('20050114','yyyymmdd'),to_date('20050114','yyyymmdd'));
insert into TimeSheets values(to_date('20050117','yyyymmdd'),to_date('20050117','yyyymmdd'));
commit;
SQL
Solution 1
How to use an inline view
select StartDate,min(EndDate) as EndDate
from
(select a.StartDate,b.EndDate
from TimeSheets a,TimeSheets b
where a.EndDate and not exists(select 1 from TimeSheets c
where (c.StartDate < a.StartDate and a.StartDate or (c.StartDate group by StartDate
order by StartDate;
Solution 2
How to use an inline view
select a.StartDate,min(b.EndDate) as EndDate
from TimeSheets a,TimeSheets b
where a.EndDate and not exists(select 1 from TimeSheets c
where (c.StartDate < a.StartDate and a.StartDate or (c.StartDate group by a.StartDate
order by a.StartDate;
Solution 3
How to use an inline view
SELECT startdate, MIN(enddate) AS enddate
FROM (SELECT T1.startdate, T2.enddate
FROM Timesheets T1, Timesheets T2
WHERE T1.enddate T3.startdate AND T1.startdate = T3.startdate AND T2.enddate < T3.enddate)))
GROUP BY startdate;
Solution 4
How to use an inline view
SELECT startdate, MIN(enddate) AS enddate
FROM (SELECT T1.startdate AS startdate, T2.enddate AS enddate
FROM Timesheets T1, Timesheets T2, Timesheets T3
WHERE T1.enddate T3.startdate AND T1.startdate = T3.startdate AND T2.enddate < T3.enddate) THEN 1 END) = 0)
GROUP BY startdate;
Solution 5
How to use a hierarchical queries (> 10g)
select min(connect_by_root StartDate) as StartDate,EndDate from TimeSheets where connect_by_IsLeaf = 1 connect by nocycle prior EndDate between StartDate and EndDate group by EndDate order by StartDate;
Solution 6
How to use hierarchical queries (> 10g)
select connect_by_root StartDate as StartDate,EndDate
from TimeSheets a
where connect_by_IsLeaf = 1
start with not exists(select 1 from TimeSheets b
where a.RowID != b.RowID
and a.StartDate between b.StartDate and b.EndDate)
connect by nocycle prior EndDate between StartDate and EndDate
order by StartDate;
Solution 7
How to use analysis of the relevant number range
select min(StartDate) as StartDate,max(EndDate) as EndDate
from (select StartDate,EndDate,
sum(willSum) over(order by StartDate) as GID
from (select StartDate,EndDate,
case when StartDate
range between unbounded preceding
and 1 preceding)
then 0 else 1 end as willSum
from TimeSheets))
group by GID
order by StartDate;
How does one get the time difference between two date columns?
Oracle allows two date values to be subtracted from each other returning a numeric value indicating the number of days between the two dates (may be a fraction). This example will show how to relate it back to a time value.
Let’s investigate some solutions. Test data:
CREATE TABLE dates (date1 DATE, date2 DATE); INSERT INTO dates VALUES (SYSDATE, SYSDATE-1); INSERT INTO dates VALUES (SYSDATE, SYSDATE-1/24); INSERT INTO dates VALUES (SYSDATE, SYSDATE-1/60/24); SELECT (date1 - date2) FROM dates; DATE1-DATE2 ----------- 1 .041666667 .000694444
Solution 1
SELECT floor(((date1-date2)*24*60*60)/3600) || ' HOURS ' || floor((((date1-date2)*24*60*60) - floor(((date1-date2)*24*60*60)/3600)*3600)/60) || ' MINUTES ' || round((((date1-date2)*24*60*60) - floor(((date1-date2)*24*60*60)/3600)*3600 - (floor((((date1-date2)*24*60*60) - floor(((date1-date2)*24*60*60)/3600)*3600)/60)*60) )) || ' SECS ' time_difference FROM dates; TIME_DIFFERENCE -------------------------------------------------------------------------------- 24 HOURS 0 MINUTES 0 SECS 1 HOURS 0 MINUTES 0 SECS 0 HOURS 1 MINUTES 0 SECS
An enhancement to solution 1
SELECT floor((date1-date2)*24) || ' HOURS ' || mod(floor((date1-date2)*24*60),60) || ' MINUTES ' || mod(floor((date1-date2)*24*60*60),60) || ' SECS ' time_difference FROM dates;</code> TIME_DIFFERENCE -------------------------------------------------------------------------------- 24 HOURS 0 MINUTES 0 SECS 1 HOURS 0 MINUTES 0 SECS 0 HOURS 1 MINUTES 0 SECS
Solution 2
If you don’t want to go through the floor and ceiling math, try this method (contributed by Erik Wile):
SELECT to_number( to_char(to_date('1','J') +
(date1 - date2), 'J') - 1) days,
to_char(to_date('00:00:00','HH24:MI:SS') +
(date1 - date2), 'HH24:MI:SS') time
FROM dates;
DAYS TIME
---------- --------
1 00:00:00
0 01:00:00
0 00:01:00
Solution 3: If u want an easier method, use numtodsinterval()
NUMTODSINTERVAL: This function is new to Oracle 9i. It takes two arguments numtodsinterval(x,c) where x is a number and c is a character string denoting the units of x. Valid units are ‘DAY’, ‘HOUR’, ‘MINUTE’ and ‘SECOND’.
This function converts the number x into an INTERVAL DAY TO SECOND datatype.
select numtodsinterval(date1-date2,'day') time_difference from dates; TIME_DIFFERENCE ---------------------------------------------------------------- +000000001 00:00:00.000000000 +000000000 01:00:00.000000000 +000000000 00:01:00.000000000
Concatenate sets of intervals
CLEAR;
with t as (
select 11 AS ID, 1 AS val1, 'B' AS val2 from dual union all
select 12,1,'A' from dual union ALL
select 13,1,'A' from dual union all
select 14,1,'B' from dual union ALL
select 15,1,'A' from dual UNION ALL
select 16,1,'B' from dual union ALL
select 17,1,'B' from dual union ALL
select 18,1,'A' from dual union ALL
select 19,2,'B' from dual union all
select 20,2,'A' from dual union ALL
select 21,2,'B' from dual union ALL
select 22,2,'A' from dual union ALL
select 23,2,'B' from dual union ALL
select 24,2,'A' from dual union ALL
select 25,1,'B' from dual union ALL
select 26,1,'A' from dual
),
tt AS(select t.*,
case when lag (val2) over (partition by val1 order by id) || val2 in ('A', 'BA') then 1 end as start_of_group,
case when lead(val2) over (partition by val1 order by id) || val2 in ('B', 'AB') then 1 end as end_of_group
from t),
ttt AS (SELECT tt.*, COUNT(start_of_group) over(PARTITION BY val1 ORDER BY id) AS group_no FROM tt),
tttt AS (SELECT row_number() over(ORDER BY val1, group_no) AS rn,
val1,
t1.ID AS id1,
t2.ID AS id2,
t1.val2 AS VAL2A,
t2.val2 AS VAL2B
FROM (SELECT * FROM ttt WHERE start_of_group IS NOT NULL) t1
FULL JOIN (SELECT * FROM ttt WHERE end_of_group IS NOT NULL) t2
USING (val1, group_no)
ORDER BY rn)
SELECT * FROM tttt;
Getting a Request Parameter Using JSTL in a JSP Page
When using the JSTL’s expression language (see Enabling the JSTL Expression Language in a JSP Page), the request parameters are made available in the implicit object param. This example demonstrates how to include the value of a request parameter from the query string or posted data in the generated output:
<%-- Declare the core library --%>
<%@ taglib uri="/WEB-INF/tld/c.tld" prefix="c" %>
<c:choose>
<c:when test="${empty param.name}">
Please enter your name.
</c:when>
<c:otherwise>
Hello <b><c:out value="${param.name}" /></b>!
</c:otherwise>
</c:choose>
If the page was accessed with the URL:
http://hostname.com/mywebapp/mypage.jsp?name=UserName
the resulting output would be:
Hello UserName!
Getting a Request Parameter in a Servlet
In a GET request, the request parameters are taken from the query string (the data following the question mark on the URL). For example, the URL http://hostname.com?p1=v1&p2=v2 contains two request parameters – – p1 and p2. In a POST request, the request parameters are taken from both query string and the posted data which is encoded in the body of the request. This example demonstrates how to get the value of a request parameter in either a GET or POST request.
// See also The Quintessential Servlet
// This method is called by the servlet container to process a GET request.
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
doGetOrPost(req, resp);
}
// This method is called by the servlet container to process a POST request.
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
doGetOrPost(req, resp);
}
// This method handles both GET and POST requests.
private void doGetOrPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
// Get the value of a request parameter; the name is case-sensitive
String name = "param";
String value = req.getParameter(name);
if (value == null) {
// The request parameter 'param' was not present in the query string
// e.g. http://hostname.com?a=b
} else if ("".equals(value)) {
// The request parameter 'param' was present in the query string but has no value
// e.g. http://hostname.com?param=&a=b
}
// The following generates a page showing all the request parameters
PrintWriter out = resp.getWriter();
resp.setContentType("text/plain");
// Get the values of all request parameters
Enumeration enum = req.getParameterNames();
for (; enum.hasMoreElements(); ) {
// Get the name of the request parameter
name = (String)enum.nextElement();
out.println(name);
// Get the value of the request parameter
value = req.getParameter(name);
// If the request parameter can appear more than once in the query string, get all values
String[] values = req.getParameterValues(name);
for (int i=0; i<values.length; i++) {
out.println(" "+values[i]);
}
}
out.close();
}
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