473,322 Members | 1,401 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,322 software developers and data experts.

Creating rows based on date range from another table

I wish to build a table based on values from another table.
I need to populate a table between two dates from another table. Using
the START_DT and END_DT, create records between those dates.
I need a new column that is the days between the date and the MID_DT
The data I wish to end with would look something like this:

PERIOD DATE DAY_NO
200602 2005-07-06 -89
200602 2005-07-07 -88
200602 2005-07-08 -87
<...>
200602 2005-10-02 -2
200602 2005-10-03 -1
200602 2005-10-04 0
200602 2005-10-05 1
<...>
200602 2005-12-18 75

CREATE TABLE "dbo"."tblDates"
("PERIOD" CHAR(6) NOT NULL,
"START_DT" DATETIME NULL,
"MID_DT" DATETIME NULL,
"END_DT" DATETIME NOT NULL)

INSERT INTO tblDates VALUES('200505',2005-04-12,2005-07-05,2005-09-12)
INSERT INTO tblDates VALUES('200602',2005-07-06,2005-10-03,2005-12-18)
INSERT INTO tblDates VALUES('200603',2005-10-04,2006-01-17,2006-03-27)
INSERT INTO tblDates VALUES('200604',2006-01-18,2006-04-10,2006-06-19)
INSERT INTO tblDates VALUES('200605',2006-04-11,2006-07-04,2006-09-11)
INSERT INTO tblDates VALUES('200702',2006-07-05,2006-10-02,2006-12-18)

Aug 20 '06 #1
7 8366
rcamarda (ro*****@hotmail.com) writes:
I wish to build a table based on values from another table.
I need to populate a table between two dates from another table. Using
the START_DT and END_DT, create records between those dates.
I need a new column that is the days between the date and the MID_DT
The data I wish to end with would look something like this:

PERIOD DATE DAY_NO
200602 2005-07-06 -89
200602 2005-07-07 -88
200602 2005-07-08 -87
<...>
200602 2005-10-02 -2
200602 2005-10-03 -1
200602 2005-10-04 0
200602 2005-10-05 1
<...>
200602 2005-12-18 75

CREATE TABLE "dbo"."tblDates"
("PERIOD" CHAR(6) NOT NULL,
"START_DT" DATETIME NULL,
"MID_DT" DATETIME NULL,
"END_DT" DATETIME NOT NULL)

INSERT INTO tblDates VALUES('200505',2005-04-12,2005-07-05,2005-09-12)
INSERT INTO tblDates VALUES('200602',2005-07-06,2005-10-03,2005-12-18)
INSERT INTO tblDates VALUES('200603',2005-10-04,2006-01-17,2006-03-27)
INSERT INTO tblDates VALUES('200604',2006-01-18,2006-04-10,2006-06-19)
INSERT INTO tblDates VALUES('200605',2006-04-11,2006-07-04,2006-09-11)
INSERT INTO tblDates VALUES('200702',2006-07-05,2006-10-02,2006-12-18)
Thanks for posting table definition and data. However, I would appreciate
if you also tested your repro script before you post. I was puzzled not
getting any rows back first from my query, but then I realised that
2005-04-12 2005-09-12. (Run the above folliwed by a SELECT on the
table to see why.)

Anyway, as I said in another newsgroup, you need a table of numbers. Here
is a way to create such a table with a million numbers:

CREATE TABLE Numbers (Number int NOT NULL PRIMARY KEY);
WITH digits (d) AS (
SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION
SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION
SELECT 7 UNION SELECT 8 UNION SELECT 9 UNION
SELECT 0)
INSERT Numbers (Number)
SELECT Number
FROM (SELECT i.d + ii.d * 10 + iii.d * 100 + iv.d * 1000 +
v.d * 10000 + vi.d * 100000 AS Number
FROM digits i
CROSS JOIN digits ii
CROSS JOIN digits iii
CROSS JOIN digits iv
CROSS JOIN digits v
CROSS JOIN digits vi) AS Numbers
WHERE Number 0

Given this table, we can write this query:

SELECT d.PERIOD, dateadd(DAY, n.Number - 1, d.START_DT),
datediff(DAY, d.MID_DT, dateadd(DAY, n.Number - 1, d.START_DT))
FROM tblDates d
CROSS JOIN Numbers n
WHERE dateadd(DAY, n.Number - 1, d.START_DT)
BETWEEN d.START_DT AND d.END_DT
ORDER BY d.PERIOD, 2
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pro...ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinf...ons/books.mspx
Aug 20 '06 #2
Erland,
Sorry about the insert, i see that its returning what I did not expect.
Originally I had the dates quoted, but sql bawked at that. I've been
trying to fix the insert, but after trying cast and convert, it still
wont go.
This gives error about conversion:
INSERT INTO tblDates VALUES ( '200602',cast('2005-07-06' AS
DATETIME),CAST('2005-10-03' AS DATETIME), CAST('2005-12-18' AS
DATETIME))
AH! Finally got this to work:
INSERT INTO tblDates VALUES ('200505' ,convert(datetime,
'2005-04-12'),convert(datetime,'2005-07-05'),
convert(datetime,'2005-09-12' ))

Im still trying to grasp the use of the numbers table. I have a D_Day
table that is the days from 1900 - 2100. Could that be used somehow?
(1900-01-01 has a surrogate key of 1 and 1900-01-02 is 2 and so forth)
You solution works, which I am appreciative of, tho it will take me
working with the code to figure out why :)
Thanks for teaching me something new!
Rob


Erland Sommarskog wrote:
rcamarda (ro*****@hotmail.com) writes:
I wish to build a table based on values from another table.
I need to populate a table between two dates from another table. Using
the START_DT and END_DT, create records between those dates.
I need a new column that is the days between the date and the MID_DT
The data I wish to end with would look something like this:

PERIOD DATE DAY_NO
200602 2005-07-06 -89
200602 2005-07-07 -88
200602 2005-07-08 -87
<...>
200602 2005-10-02 -2
200602 2005-10-03 -1
200602 2005-10-04 0
200602 2005-10-05 1
<...>
200602 2005-12-18 75

CREATE TABLE "dbo"."tblDates"
("PERIOD" CHAR(6) NOT NULL,
"START_DT" DATETIME NULL,
"MID_DT" DATETIME NULL,
"END_DT" DATETIME NOT NULL)

INSERT INTO tblDates VALUES('200505',2005-04-12,2005-07-05,2005-09-12)
INSERT INTO tblDates VALUES('200602',2005-07-06,2005-10-03,2005-12-18)
INSERT INTO tblDates VALUES('200603',2005-10-04,2006-01-17,2006-03-27)
INSERT INTO tblDates VALUES('200604',2006-01-18,2006-04-10,2006-06-19)
INSERT INTO tblDates VALUES('200605',2006-04-11,2006-07-04,2006-09-11)
INSERT INTO tblDates VALUES('200702',2006-07-05,2006-10-02,2006-12-18)

Thanks for posting table definition and data. However, I would appreciate
if you also tested your repro script before you post. I was puzzled not
getting any rows back first from my query, but then I realised that
2005-04-12 2005-09-12. (Run the above folliwed by a SELECT on the
table to see why.)

Anyway, as I said in another newsgroup, you need a table of numbers. Here
is a way to create such a table with a million numbers:

CREATE TABLE Numbers (Number int NOT NULL PRIMARY KEY);
WITH digits (d) AS (
SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION
SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION
SELECT 7 UNION SELECT 8 UNION SELECT 9 UNION
SELECT 0)
INSERT Numbers (Number)
SELECT Number
FROM (SELECT i.d + ii.d * 10 + iii.d * 100 + iv.d * 1000 +
v.d * 10000 + vi.d * 100000 AS Number
FROM digits i
CROSS JOIN digits ii
CROSS JOIN digits iii
CROSS JOIN digits iv
CROSS JOIN digits v
CROSS JOIN digits vi) AS Numbers
WHERE Number 0

Given this table, we can write this query:

SELECT d.PERIOD, dateadd(DAY, n.Number - 1, d.START_DT),
datediff(DAY, d.MID_DT, dateadd(DAY, n.Number - 1, d.START_DT))
FROM tblDates d
CROSS JOIN Numbers n
WHERE dateadd(DAY, n.Number - 1, d.START_DT)
BETWEEN d.START_DT AND d.END_DT
ORDER BY d.PERIOD, 2
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pro...ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinf...ons/books.mspx
Aug 20 '06 #3
rcamarda (ro*****@hotmail.com) writes:
Sorry about the insert, i see that its returning what I did not expect.
Originally I had the dates quoted, but sql bawked at that. I've been
trying to fix the insert, but after trying cast and convert, it still
wont go.
This gives error about conversion:
INSERT INTO tblDates VALUES ( '200602',cast('2005-07-06' AS
Yes, the above format could fail. There are three date formats in SQL
Server that are safe:

YYYYMMDD
YYYYMMDDTHH:MM:SS[.fff]
YYYY-MM-DDZ

Here T and Z stand for themselves.

Other formats are interpretated depending on DATEFORMAT and LANGUAGE
setting, and can fail or produced unexpected results if you don't know
what is going on.
Im still trying to grasp the use of the numbers table. I have a D_Day
table that is the days from 1900 - 2100. Could that be used somehow?
(1900-01-01 has a surrogate key of 1 and 1900-01-02 is 2 and so forth)
Yes, that dates table is essentially a table of numbers with a different
names. In fact, it appears that it has all the numbers as well!

I used a table of numbers, as numbers is the more general concept and
can be used in more places. But in fact, I added a table of dates to
our system before I added a table of numbers.

I leave it as an exercise to you how to use the dates table instead.
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pro...ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinf...ons/books.mspx
Aug 20 '06 #4
On Sun, 20 Aug 2006 12:38:11 +0000 (UTC), Erland Sommarskog
<es****@sommarskog.sewrote:
>rcamarda (ro*****@hotmail.com) writes:
>I wish to build a table based on values from another table.
I need to populate a table between two dates from another table. Using
the START_DT and END_DT, create records between those dates.
I need a new column that is the days between the date and the MID_DT
The data I wish to end with would look something like this:

PERIOD DATE DAY_NO
200602 2005-07-06 -89
200602 2005-07-07 -88
200602 2005-07-08 -87
<...>
200602 2005-10-02 -2
200602 2005-10-03 -1
200602 2005-10-04 0
200602 2005-10-05 1
<...>
200602 2005-12-18 75
[snip]
>INSERT INTO tblDates VALUES('200602',2005-07-06,2005-10-03,2005-12-18)
>Anyway, as I said in another newsgroup, you need a table of numbers. Here
is a way to create such a table with a million numbers:
What are the pros and cons of relying on such a table vs. using a
WHILE loop? Based on Rob's context of student registrations, let's
assume we're talking about a maximum of 300 iterations per row in
the original tblDates table.
Aug 21 '06 #5
Ed Murphy (em*******@socal.rr.com) writes:
What are the pros and cons of relying on such a table vs. using a
WHILE loop? Based on Rob's context of student registrations, let's
assume we're talking about a maximum of 300 iterations per row in
the original tblDates table.
The one risk with a table of numbers is that if you run of numbers, you
will get an incorrect result. That is one reason why I'm reluctant to
use it, if there are alternative solutions. But for a case like this,
when you need to fill up a space, a table of numbers - or dates - is what
you need.

A loop is more complex to program, and easier go wrong. And as a generic
solution, you face scalability problems.

--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pro...ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinf...ons/books.mspx
Aug 21 '06 #6
On Mon, 21 Aug 2006 08:05:49 +0000 (UTC), Erland Sommarskog
<es****@sommarskog.sewrote:
>Ed Murphy (em*******@socal.rr.com) writes:
>What are the pros and cons of relying on such a table vs. using a
WHILE loop? Based on Rob's context of student registrations, let's
assume we're talking about a maximum of 300 iterations per row in
the original tblDates table.

The one risk with a table of numbers is that if you run of numbers, you
will get an incorrect result. That is one reason why I'm reluctant to
use it, if there are alternative solutions. But for a case like this,
when you need to fill up a space, a table of numbers - or dates - is what
you need.

A loop is more complex to program, and easier go wrong.
I disagree, but then I have somewhat more experience with imperative
than functional programming. Consider:

x = first_date
while x <= last_date
insert x, datediff(x, mid_date) into <table>
x = dateadd(x, 1)
end while

versus

select dateadd(first_date, n), n - datediff(mid_date, first_date)
into <table>
from numbers
where n between 0 and datediff(end_date, first_date)

Okay, "where n between <limits>" makes sense as an analogue to a while
loop, but that stuff in line 1 looks like the stuff of headaches.
And as a generic
solution, you face scalability problems.
I kind of figured. The query seems easy to get wrong, though, if
you're not familiar with the pattern; I first wrote it as "where
dateadd(first_date, n) between first_date and last_date", but that
seems like it'd be a good bit slower.
Aug 22 '06 #7
Ed Murphy (em*******@socal.rr.com) writes:
I disagree, but then I have somewhat more experience with imperative
than functional programming. Consider:

x = first_date
while x <= last_date
insert x, datediff(x, mid_date) into <table>
x = dateadd(x, 1)
end while

versus

select dateadd(first_date, n), n - datediff(mid_date, first_date)
into <table>
from numbers
where n between 0 and datediff(end_date, first_date)

Okay, "where n between <limits>" makes sense as an analogue to a while
loop, but that stuff in line 1 looks like the stuff of headaches.
Loops are particularly prone to two sorts of errors:

* They goes on forever, could be because of a sloppy mistake, of because the
logic is complicated.
* One-off errors because of incorrect loop conditions.

One-off errors are easy to make with set-based queries as well, but the
risk of infinite loops is nothing you have to lose sleep over.

--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/pro...ads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinf...ons/books.mspx
Aug 22 '06 #8

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

7
by: Thomas R. Hummel | last post by:
Hello all, I am trying to write a query that compares a member's enrollment period with the products that their group has had during that period (all members belong to a group and the products...
1
by: fak | last post by:
I have a workorder entry form. There is a table that contains workorder information and another table that contains work dates that are closed (fully booked). When the workorder form is being...
5
by: Sami | last post by:
Please bear with me, and if you answer this question, please do it step by step. I am new at Access, not at all sophisticated. I am using Office XP. This will need to be read in Access for...
3
by: rugger81 | last post by:
I am currently working in the sql server 2000 environment and I want to write a function to pull all dates within a given date range. I have created several diferent ways to do this but I am...
4
by: Joanie | last post by:
I have a form that records dates of unavailability for a worker. Based on what is entered in the simple table behind the form, many calculations take place to create employee "load" balance. Each...
4
by: norma.j.hildebrand | last post by:
I have a database that has a field (performance standard), every year the standard changed which was not a problem since we start out each year with a blank database and just change the standards...
12
jaccess
by: jaccess | last post by:
Hello all, I am trying to create a running total based on a specific date range that is to be entered into a form. I currently have the form set up with 2 text boxes (date1 and date2) which are...
3
by: Vinda | last post by:
Hi Bytes, Using a previous question as a base Access 2000 Inserting multiple rows based on a date range. I also wanted to insert multiple rows into a table according to a date range supplied by a...
5
by: CD Tom | last post by:
Here's my problem. I have a person in New Zealand that I'm having problems with the date. Everything works fine except I have a date field in one form that updates another table with the date. I'm...
0
by: DolphinDB | last post by:
Tired of spending countless mintues downsampling your data? Look no further! In this article, you’ll learn how to efficiently downsample 6.48 billion high-frequency records to 61 million...
1
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 6 Mar 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, we are pleased to welcome back...
0
by: jfyes | last post by:
As a hardware engineer, after seeing that CEIWEI recently released a new tool for Modbus RTU Over TCP/UDP filtering and monitoring, I actively went to its official website to take a look. It turned...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
1
by: Shællîpôpï 09 | last post by:
If u are using a keypad phone, how do u turn on JavaScript, to access features like WhatsApp, Facebook, Instagram....
0
by: af34tf | last post by:
Hi Guys, I have a domain whose name is BytesLimited.com, and I want to sell it. Does anyone know about platforms that allow me to list my domain in auction for free. Thank you
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 3 Apr 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome former...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.