Search results

From what I can understand, neither of your designs seem quite "right" but I also can't make sense of your test results or the figures you are quoting. Why would you want to make 800,000 calls to a procedure? Sounds like you are building a sequential row-by-row process when a more set-based...

It's hard to do design in an online forum without the opportunity to analyse the real life scenario properly but your description does suggest some design issues. I'm not clear what the benefit is of duplicating "dummy" rows for people whose data is not yet known. Why not just insert the rows...

They don't need to buy a licence for SQL Server Express. What is it you want to protect though? Apparently not the data. Switching off features in the UI is a good way to make users think their data is "safe" when it isn't. That's arguably worse than not securing things at all. By deceiving...

"User Level Security" in Access was always a lie. If you wanted a way to control user interface features based on user credentials then that's easy to achieve in your own code. If you want a secure database based with role-based permissions then you need to put your data into a DBMS with those...

I would use a "numbers" table for this kind of thing (single column table with all the integers from 0 to some big N). INSERT INTO your_table (col, ...) SELECT num, ... FROM numbers WHERE num>=7270 AND num<=9028; Join this with whatever your other query is to populate the other column(s). No...

Just a suggestion but have you considered using SQL Server spatial types? SQL Server has a built-in Geometry data type that supports industry standards for GIS data and comes with the functions and indexes you need to use it. The UK National Grid is flat so the Geometry type is probably what you...

It's worth clarifying something that was said here. It's actually not the case that having multiple tables with the same structure is contrary to any principles of normalization. None of the classical normal forms is violated simply by having the same attributes in more than one place in the...

Because that way you would get the worst of both worlds: no truly domain-independent surrogate key and your business key is tied to a autonumber-type column with all the inbuilt limitations that implies. Use in-table autonumber columns for surrogate (hidden) keys only - that's what they are...

This feels like it ought to be driven by your product and marketing strategy rather than just being a technical question about a version upgrade. Do you know what is the future roadmap for your product? Or what features you will want to offer in future? 64bit support maybe? A client-server...

Hi Galaxiom, My reply was just intended as a basic example of syntax to get leovinous started. It's perfectly possible to modify it to support the more realistic scenario where the weight limit is in another table. I'm not sure why you think otherwise but maybe I'm missing your point. ALTER...

Maybe this example will help you. Depending on your version of Access Jet/Ace you may have to execute this code against a local or remote connection rather than in the SQL window. ALTER TABLE flight ADD CONSTRAINT ck1 CHECK (cargoweight <= 2500 AND passengers = 0 OR cargoweight <= 1500)...

No. None of the conventional normal forms is concerned with the problem of tables that may "overlap" (may contain some or all of the same types of data). The Principle of Orthogonal Design (POD) is a design principle that attempts to fix that by formalising the problem. POD is discussed at some...

Thales may not get rich as a gambler but Galaxiom won't win any prizes at maths until he learns about the Birthday Problem ;). Even assuming guid distribution is perfectly random (which it isn't) then the probability of a duplicate is greater than 50:50 after fewer than 1E20 guids. Still, for...

GBalcom, Software development is a very broad and diverse field and obviously very competitive. The best advice I can give is try not to be too specialist. If you want to be an application developer then Java, .NET, C, C++ are by far the most common languages and to maximise appeal to future...

In contrast to Rain's reply, I'd like to state an alternative point of view that composite keys are not only useful and desirable but virtually an essential element of effective database design. You cannot afford to ignore, discard or fail to enforce a key just because it happens to be...

The question arose yesterday of whether and where Microsoft document what a candidate key is. The following definition published by Microsoft seems like a perfectly OK one (with one possible quibble that in the relational model keys are supposed to be irreducible as well as uniquely...

I would like to thank you for that little quote but it seems I'm no longer here. I'm not mentioned in Microsoft help files so clearly I don't exist.

Rain, I don't claim any such thing. I said it's not Microsoft's mission or practice to teach relational database design principles and that's not the place any wise person ought to go to learn about it. There are plenty of people I know at Microsoft who know as much or more about database design...

Microsoft's terminology? Relational database concepts (relations, keys, foreign keys, etc) were invented before Microsoft even existed. I hope no professional person relies on Microsoft help files to learn about relational database design principles because as far as I know that kind of...

Here's a problem of terminology that's been discussed in these forums before - with, I think, no very satisfactory conclusion: What is a junction table? The best definition I've found is that a junction table is a table with more than one foreign key in it. If you accept that definition then I...