I have a table that has a StartDate and EndDate field, and also a ton of other fields. I need to break out each record by all the days between and including StartDate & EndDate into another table that looks exactly like the original except it has a CurrentDate field and 2 calculated fields. The CurrentDate field is the current date between StartDate and EndDate that I'm interating on.
My question is, since there are a ton of fields in this, is there any easy way from within my stored proc, to insert the entire row the cursor is currently on AND this 1 new column, without having to list out every single row in the insert statement? It's so tedious.
If your source and destination tables fit this profile:
Destination table columns are the same as your source table's columns, and
The new destination column is at the end
... then you could do something like this:
INSERT INTO dest_table
SELECT Source_Table.*, new_value
FROM Source_Table
WHERE Source_Table.PKValue = cursor.PKValue
If it's a case of your cursor resembling the destination table, something like this may work but note I haven't tested it:
CREATE PROCEDURE whatever IS
destRow dest_table%ROWTYPE;
CURSOR fromSourceTable IS
SELECT <your existing select list>, NULL AS new_value
FROM <the rest of your cursor query>;
BEGIN
FOR destRow IN fromSourceTable LOOP
destRow.new_value = <the split date>;
INSERT INTO dest_table VALUES destRow;
END LOOP;
END whatever;
I'm going out on a limb with the NULL AS new_value. If you have trouble try CAST(NULL AS DATE) AS new_value instead, and if you still have trouble try something like SYSDATE AS new_value. Again, this isn't tested but if you think it's promising and have trouble implementing I'd be happy to test it.
It's easy enough to densify the data in a single SQL statement. Assuming that you know a reasonable minimum and maximum range for your begin_date and end_date (I'll assume Jan 1, 2000 - Dec 31, 2020 for the moment but you can obviously adjust that)
WITH all_days AS (
SELECT date '2000-01-01' + level dt
FROM dual
CONNECT BY level <= date '2020-12-31' - date '2000-01-01'
)
SELECT <<list of colums from your table>>,
all_days.dt current_date
FROM your_table actual
JOIN all_days ON (actual.begin_date <= all_days.dt AND
actual.end_date >= all_days.dt)
If you don't want to hard-code the starting and ending dates, you can fetch them from your table as well. That just requires that you hit the table a second time which will generally be less efficient.
Related
In my Oracle SQL Developer, i have a table with a column with DATE format. When i insert a new row into this table, and insert a new value in this column, it automatically suggestes me the current date with the current hour.
I would like that it automatically suggestes me current date, but with 00:00:00 hour . Is there some setting or parameter that i can set in my SQL Developer to have this result?
We can't able to insert 00:00:00 hours ... the hour value should be between 1 to 12...
we can use below query to insert 00:00:00 hours but the value will be changed to 12:00:00
INSERT INTO TABLE (DATE_COL) VALUES
( TO_DATE ('11/16/2017 00:00:00 ', 'MM/DD/YYYY HH24:MI:SS '));
It seems to me that your DATE column is set with a DEFAULT of SYSDATE. This means, for any INSERT operations which do not specify a value in your DATE column, the current date and time will populate for that row. However, if INSERT operations do specify a value in your DATE column, then the specified date value will supersede the DEFAULT of SYSDATE.
If an application is controlling INSERT operations on that table, then one solution is to ensure the application utilizes the TRUNC() function to obtain your desired results. For example:
INSERT INTO tbl_target
(
col_date,
col_value
)
VALUES
(
TRUNC(SYSDATE, 'DDD'),
5000
)
;
However, if there are multiple applications or interfaces where users could be inserting new rows into the table, (e.g. using Microsoft Access or users running INSERT statements via SQL Developer) and you can't force all of those interfaces to utilize the TRUNC() function on that column during insertion, then you need to look into other options.
If you can ensure via applications that INSERT operations will not actually reference the DATE, then you can simply ALTER the table so that the DATE column will have a DEFAULT of TRUNC(SYSDATE). A CHECK CONSTRAINT can be added for further integrity:
ALTER TABLE tbl_target
MODIFY
(
col_date DATE DEFAULT TRUNC(SYSDATE, 'DDD') NOT NULL
)
ADD
(
CONSTRAINT tbl_target_CHK_dt CHECK(col_date = TRUNC(col_date, 'DDD'))
)
;
However, if users still have the freedom to specify the DATE when inserting new rows, you will want to use a TRIGGER:
CREATE OR REPLACE TRIGGER tbl_target_biu_row
BEFORE INSERT OR UPDATE OF col_val
ON tbl_target
FOR EACH ROW
BEGIN
:NEW.col_date := TRUNC(SYSDATE, 'DDD');
END tbl_target_biu_row
;
This will take of needing to manage the application code of all external INSERT operations on the table. Keep in mind, the above trigger is also modifying the DATE column if a user updates the specified value column.
In Oracle 12, if I create a very simple table, TEST_TABLE, with a single varchar2(128) column 'name' and populate that column with lots of strings of '20170831', and my sysdate shows:
SELECT sysdate FROM dual;
29-SEP-17
then why does this SQL query return 0 rows:
SELECT TO_DATE(name,'YYYYMMDD'),
TO_DATE(TRUNC(SYSDATE),'DD-MM-YYYY')
FROM TEST_TABLE
WHERE TO_DATE(name,'YYYYMMDD') < TO_DATE(TRUNC(SYSDATE),'DD-MM-YYYY');
(This is a very simplified example of a problem I'm facing in my partition maintenance script and have not been able to solve for the last week).
Thank you in advance for any assistance related to the above query.
Midnight(time part is 00:00:00.000):
SELECT TO_DATE(name,'YYYYMMDD'), TRUNC(SYSDATE)
FROM TEST_TABLE
WHERE TO_DATE(name,'YYYYMMDD') <= TRUNC(SYSDATE);
You could also try:
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
Just don't apply a to_date() to an already date field, this because, it will implicitly convert that date into varchar and then apply the to_date() function to it, for example your query part TO_DATE(TRUNC(SYSDATE),'DD-MM-YYYY') is interpreted like this:
TO_DATE(TO_CHAR(TRUNC(SYSDATE)),'DD-MM-YYYY')
TO_CHAR(TRUNC(SYSDATE)) is getting a char something like: '31-AUG-17', and that is not in 'DD-MM-YYYY' format.
And because of that, TO_DATE(TRUNC(SYSDATE),'DD-MM-YYYY') gets something like this: 29/09/0017 and your filter goes FALSE and gets no results.
I'm very new to using Oracle (I'm using TOAD 11.6), I would like to turn this code into something that would work in Oracle, how do I do it?!
declare #yesterday datetime
set #yesterday = (select cast(cast(getdate() as varchar(12)) as datetime)-1)
select *
from my_table
where disp_cret_dt >= #yesterday
Thanks in advance!!
I think you're after:
select *
from my_table
where disp_cret_dt >= trunc(sysdate-1);
That's assuming that disp_cret_dt is of datatype DATE or TIMESTAMP.
In Oracle, differences between two dates (which includes the time) are always returned as the number of days difference - and it can contain fractions of a day (eg. today at 12 noon - today at midnight = 0.5).
SYSDATE is Oracle's way of returning the current date+time.
TRUNC(dt, level) is the way you can truncate the date to whichever level you like - the default is day (which will just reset the time to midnight - 00:00), but you could do month (takes it back to the first of the month), hours etc etc.
Below is an equivalent code for oracle
declare yesterday date;
begin
select to_char(sysdate-1,'dd/mm/yyyy hh:mi:ss') into yesterday from dual;
select * into var1,var2..varn from my_table
where disp_cret_dt>=yesterday;
end;
1.Dual is temporary table in oracle which contains one column named as dummy with data type of varchar2(1). For more Refer here.
2.The SELECT INTO clause of SQL is used to retrieve one row or set of columns from the Oracle database. The SELECT INTO is actually a standard SQL query where the SELECT INTO clause is used to place the returned data into predefined variables.
If you want to return three items you have to define three variables in our pl/sql block with respective data types after applying these changes to above code it looks
declare
yesterday date;
v_item1 number;
v_item2 varchar2(11);
v_item3 date;
begin
select to_char(sysdate-1,'dd/mm/yyyy hh:mi:ss') into yesterday from dual;
select item1, item2,item3 into v_item1,v_item2,v_item3 from my_table
where disp_cret_dt>=yesterday;
Dbms_output.put_line('Item1: '||v_item1||'Item2: '||v_item2||'Item3: '||v_item3);--Displaying values
end;
Note: In the above code if your select query will returns more than one row for each yesterday value then it will throws an error. Because at a time a variable will holds one value. In that scenario we have to choose collections in oracle for more Refer here.
if you want to have "yesterday" in a seperate variable because you use it more than once in your code, assign "sysdate-1" to it:
declare
yesterday date := trunc(sysdate - 1);
begin
select * from my_table where disp_cret_dt >= yesterday;
end;
I would like to write a stored procedure that inserts some data into a table from another table (table b). But does one date from table b at a time. The date range is given as parameters in the stored procedures
Is my logic correct? I would really appreciate some tips
CREATE OR REPLACE PROCEDURE database_name.test(start_date,end_date)
-- declare parameters convert dates into numbers
BEGIN FOR i in start_date..end_date LOOP INSERT INTO SOME_TABLE SELECT
* FROM OTHER_TABLE WHERE date = i END LOOP
END database_name.test;
Is there a reason that you need a loop? I would think that you'd just want
INSERT INTO destination_table
SELECT *
FROM source_table
WHERE source_table.date_column BETWEEN p_start_date AND p_end_date;
What you really need is not clear (from my point of view). If you need to create some dates list, you could use the following query to generate a list a dates between the begin date [bgin_d] and the end date [end_d]:
WITH dtes AS (SELECT SYSDATE bgin_d, SYSDATE + 30 end_d FROM DUAL)
SELECT bgin_d + LEVEL
FROM dtes
CONNECT BY bgin_d <= end_d;
I have to make a process in Oracle/PLSQL. I have to verify that the interval of time between start_date and end_date from a new row that I create must not intersect other start_dates and end_dates from other rows.
Now I need to check each row for that condition and if it doesn't correspond the repetitive instruction should stop and after that to display a message such as "The interval of time given is not correct".
I don't know how to make repetitive instructions in Oracle/PLSQL and I would appreciate if you would help me.
I need a loop or smth like that to verify each row in my table that the interval of time given by the date_hour_i and date_hour_e does not intersect the other intervals of time given by the rest of the rows. One more specification....the dates from each row correspond to a client and a employee that performs a haircut to the client in the given interval of time....and i want somehow not to let to introduce a new row if for the same client(or other client) and employee, the new interval of time intersects the other intervals of time with the same/other client and employee....i hope i made myself clear...
Two links for your reading pleasure:-
Time intervals with no overlaps
and
Avoiding overlap values...
why check each row? just query for the start and end times. if the result > 0, output the error message, else, insert.
i assume this will be during the BEFORE INSERT OR UPDATE trigger.
you will want to query the existing table for overlaps in the dates - but this will give a mutating trigger error.
You can get around this by using PRAGMA AUTONOMOUS_TRANSACTION to spawn a new thread.
alternately - you could save each date range in a secondary table, and use that to query against on each insert... something like the following (uncompiled)
CREATE OR REPLACE TRIGGER mytrigger
BEFORE INSERT OR UPDATE ON mytable FOR EACH ROW
DECLARE
cnt number;
BEGIN
SELECT count(*) into cnt
FROM reserved_date_range
WHERE :new.begin_date BETWEEN begin_dt and end_dt
if ( cnt > 0 ) then
raise_application_error(-20000,'Overlapping date ranges');
else
insert into reserved_date_range( begin_dt, end_dt )
values ( :new.begin_date, :new.end_date );
end if;
End;
/
Say your table is tab1 and the start date is stdate and end date is endate
also let new start date and new end date be in PLSQL variables v_stdate and v_endate.
so your insert can be something like
insert into tab1 (stdate,endate)
select v_stdate,v_endate from dual
where not exists(
select 'overlap' from tab1 t1
where v_stdate between(t1.stdate and nvl(t1.endate,v_endate)
or v_endate between(t1.stdate and nvl(t1.endate,v_endate)
)
The solution to this problem is a bit complicated because of concurrency issues. In your case you are scheduling an event (or a resource).So I suppose you have a table that holds resource (say client). Before you add another schedule (or event) for a client you should lock the particular client record like.
select client_id from Clients where client_id=p_client_id for update;
Then you can verify there are no overlaps and insert the new schedule and commit.At this point the lock will be released.Any solution that does not use a serialization object is bound to be flawed due to concurrency issues.You can do it in your PLSQL or in a After Insert trigger.But it is an absolute must to lock the actual resource record.