Archives
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The real reason SELECT * queries are bad: index coverage
Are SELECT * queries bad? Sure, everyone know that. But, why?
It's returning too much data, right?
That's the common answer, but I don't think it's the right one. If you're working with a reasonably normalized database, the actual network traffic difference is pretty small.
Let's take a look at a sample. The following two queries select 326 rows from the TransactionHistoryArchive table in the AdventureWorks database (which has a total of 89K rows). The first uses a SELECT * query, the second selects a specific column:
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[T-SQL] Getting distinct, current entries from tables with timestamp / datetime fields
It's relatively easy to store data with a time dimension, but querying it is another matter. If you select from a temporal tables (one which includes historical information indicated by a timestamp or datetime column) based on your ID, you'll get a lot of duplicate records; only one or a few of those records will be applicable to a given time or timespan.
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Presentation tricks - Command Windows
Time management is a big part of a technical presentation. You want your demos to go fast enough to keep your audience's attention, but you don't want to gloss over details and lose them. Here are a few tricks I've used when showing something command line operations at a DOS prompt.
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SubSonic - Code Camp slides posted
Slides and sample code from my talk on SubSonic from the SoCal Code Camp a week ago are available here. The slides were pretty light since my talk was geared towards building some very simple sample pages on the fly.
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Checkbox Grids in ASP.NET
A simple checkbox grid is often the best user interface for mapping multiple selections in multiple categories:
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Silverlight 1.1 (Alpha) cross domain webservice access makes mashups tricky
Any web mashups, by definition, require cross-domain calls. Those cross-domain calls may happen on the client (in the browser) or on the server. Regardless of the client technology (AJAX, Flash, Silverlight, etc.), cross domain calls on the client are always more complex that server-side cross-domain calls, and for good reason. It's tricky in AJAX, and it's downright difficult in Silverlight. You'll know that Silverlight development has become more widespread when you hear a lot more complaints about this problem.
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Some keyboard input tricks for Silverlight 1.1 (Alpha)
Here are a few tricks I learned while doing my "hello world" maze game in Silverlight 1.1.