One-to-many With A Twist
Jul 23, 2005
Hi,
What is the best way to model this: Assume I have two objects: Agency
and Publisher, and both have a 1-to-n relationship to Employee. This is
a true 1-to-n relationship, as each Employee can only work for one
Agency or one Publisher. Let's assume further that I cannot introduce a
supertype (e.g. Employer) which holds the 1-to-n relationship.
My preferrd solution is to have a foreign key in Emplyee that can
either link to a primary key of Agency or Publisher (all my primary
keys are 64-bit IDs that are unqiue across the database). However, now
I won't be able to map a bi-directional association, without indicating
in Employee whether this is an "Agency" or "Publisher" relationship
(ala <ANY>).
My other option is to use two tables, AgencyEmployee and
PublisherEmployee, which can then be linked as traditional 1-to-n
bidirectional associations.
What do you guys consider best practice in this situation?
Cheers,
Jen
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Jul 18, 2007
I'm really new to SQL and looking for advice.
I'm going through the basics I don't mind doing my own research but I have an issue that needs attention and is beyond my current level.
I'm looking for a way to have any data entered into one database automatically copied to an archive database running on another machine. Items deleted in database one would be retained in database two. Database one would be clean and efficient and only reflect currently necessary information. Database two would grow indefinitely as an archive of what had/does exist in database one.
I'm sure this is quite mundane but I'm not sure what key words I'm looking for. Is there a title for this process?
Is this possible from within the SQL management studio or should I start those videos under the developer section?
I'm in the tall grass. Any pointers appreciated.
Both servers are Server2003 with SQL Server 2005 Standard Edition /Sp2
/drew
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May 10, 2007
Hi,I have a requirement to design a query that identifies items soldbetween two dates. There is a 'SoldDate' datetime field used toregister what date the item was sold.The query needs to identify all sales between the last day of theprevious month and going back one year.What I would like to do is to design a query / stored procedure thatwill dynamically create the criteria to allow the client to simply runthe query or stored proc.I know how to establish the last day of the previous month part, I'mjust not sure of how best to design the remainder of the query.Thank in advance
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Jul 20, 2005
OK,Here is my challenge.If I have a query that produces the followingItemSold_OnA01-10-2004 8:03A01-11-2004 10:05A01-12-20041:37A01-14-20047:16B01-10-20049:37B01-12-2004 11:42B01-13-20049:37But I need it to produce this insteadItemSold_On InstanceA01-10-2004 8:031A01-11-2004 10:052A01-12-20041:373A01-14-20047:164B01-10-20049:371B01-12-2004 11:422B01-13-20049:373So basically I need it to chronologically number the rows, but I needthe count to start over when the item changes.
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Nov 28, 2003
ive got a tough one for everyone this time!
i am trying to get a page up that enables me to enter a number into a box on a form, which then on clicking of a search button, queries the database, and returns 2 other fields that relate to the number found in the database, in an ASP datagrid.
the easiest way to do this would be to use OLEDB or ODBC, but the host i am using doesnt support either of them, and so i am trying to use their code, something using OBJDB, but to no avail. frankly, their code is rubbish, and im not sure how to go about doing the above.
i would be very grateful if someone could help me out with this problem,
thanks,
craig
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Apr 9, 2008
:eek:
I'm having a brain not functioning day - well who am I kidding - more like a year :rolleyes:
I need some help with some sequence numbering and cannot even get my head around the logic I want to use, let alone the actual code.
I have a dataset with 3 fields:
Area
ID
RefNo
This table contains a list of employee ID's by Area and each employee has a RefNo (counter) in each area.
The data comes from 2 different sources and is combined in this table. Some employees had no RefNo already assigned to them so I have entered their RefNo as 10000 in order to ensure they are sorted at the bottom of the list.
The ID's that have RefNo's have to keep the one they have. Therefore, I need to create RefNo's for the ones that currently have RefNo 10000.
These numbers I create have to follow on from the highest RefNo for the Area.
For example:
Area ID RefNo
A Z 1
A Y 2
A X 3
A W 10000
A V 10000
B N 1
B O 10000
B P 10000
So, for Area A, ID's W and V would have to be assigned RefNo 4 and 5, and for Area B, ID's O and P would have to be assigned RefNo 2 and 3.
Hope this makes sense to all.
BTW, am using SQL 2000 at the moment.
Thanks in advance for any help!
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Mar 25, 2014
I have Two Time fields in a table. Time(0). An "opening time" and a "closing time". They can hold any legit time.
I want to calculate in a SELECT Statement how many minutes within this range are within 9am to 5pm (which I'll convert to hours).
For example, here's an easy example:
OPEN: 9:00:00
CLOSE: 17:00:00
8 Hours/480 minutes
I could get this easy enough with a DATEDIFF function.
But what about:
OPEN: 08:00:00
CLOSE: 18:00:00
10 Hours total but only 8 of those 10 are within 9am-5pm.
Or what about:
OPEN: 10:00:00
CLOSE: 20:00:00
10 Hours total but only 7 are within 9am-5pm range.
I can calculate the total hours/minutes between the two times but not within that special range.
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Jun 11, 2007
Hi,
I would like to import an Excel spreadsheet into SQL Server 2005. I can do this quite easily using the Import/Export wizard, and have each row in the spreadsheet transfer to a new row in the database table.
However, I want to import the first few columns of the spreadsheet row into one table (called Products), but put the remaining columns into a related, three-column table, called Product_Details. In the Product_Details table, one column would hold the spreadsheet column value, the other column would be a FK integer value linked to the PK in the Products table, and the third column the primary key as normal.
So, somehow, I would need to get hold of the primary key value when the first spreadsheet columns are inserted into the Products table and then insert the remaining columns into the Product_Details table with two values per row - one value being the spreadsheet cell value, the second being the primary key of the new product in the Products table.
TIA,
Graham.
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