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C# – NullReferenceException with TableAdapter and Scalar Values

by on December 6, 2011 in ASP.NET/C#, Programming

Ok, I’ve been hacking around this particular problem for a month now, but think I’ve got a bead on how to stop it. So, I hope this helps someone! The Situation I’ve got a TableAdapter in C# and I’m using a Query to return a scalar value that ultimately becomes a double data type. The [...]

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C# / VSTO – Using Excel Ranges

by on November 28, 2011 in ASP.NET/C#, Microsoft Excel

Using Visual Studio Tools for Office (VSTO) with Excel lets you use C# (or your other favorite .NET language to leverage the power of Excel. But you will have to learn how the syntax for the Excel object model as opposed to just using VBA syntax. This post shows you how to use Excel ranges [...]

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C# – VSTO – Get Last Used Row or Cell in Excel Spreadsheet

by on October 25, 2011 in ASP.NET/C#

I have had the opportunity to get my fingers dirty with Visual Studio Tools for Office, at long last.  My project brought me back to an old familiar problem in Excel, finding the last used row in a spreadsheet. This applies equally to C#, VB, and VBA.  You just have to get access to the [...]

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C#: Break vs. Continue in Foreach Loops

by on March 16, 2010 in ASP.NET/C#

A C# Quick Tip: You’ve probably seen ‘break’ before in Switch Case statements, but it also plays an important role in Foreach Loops. To break completely out of a foreach loop (foregoing all the remaining loops), use: break; To go to the next iteration in the loop, use: continue; When is ‘break’ useful? It is [...]

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C#: That Pesky DBNull Error in Datatables

by on March 15, 2010 in ASP.NET/C#

Datatables and Tableadapters are one of the most beautiful things about C# and Visual Studio, until you’re processing rows in your datatable and you get something that reads like “The value for column ‘your_column’ in table ‘your_table’ is DBNull.”  If you go a little further, you may get:  “Exception Details: System.InvalidCastException: Specified cast is not [...]

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C# – SQL Server Foreign Key, Unique constraints

by on May 27, 2009 in ASP.NET/C#, SQL

I got tripped up today with a particularly nasty Join statement that worked perfectly form 90% of the queries, but was blowing up at times.  The error message was:  Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints. I looked and looked at this SQL code: It looked [...]

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