Hierarchical Data in SQL Server
Often times in applications, I am required to maintain data that has a hierarchical relationship such as a tree structure. The easiest way to approach this problem is to add a key to the table that refers to the record’s parent key. For example, in my last project, I needed to have a table that…
Programmatically Created GridView not Sorting
There have been times when I needed to programmatically create a DataGrid in the code behind. Perhaps this was a server control, WebPart, or just a regular page. In some case, I have found that sorting will not work on the GridView when it is programmatically created. This is usually caused by when the controls…
RiverMate – An Android App for River Levels
This free android app gives you the latest river level oberservations for rivers all over the United States. By selecting your state and/or county, you can select the rivers that you want to monitor. Add as many river gauges as you wish and they will be displayed and updated in real time on the app's…
Windows Azure: Using Windows Azure’s Service Bus to Solve Data Security Issues
In the fall of 2010, the owner of rebus technologies completed his Master's in Applied Computer Science from Columbus State Univeristy. His Master's Thesis Windows Azure: Using Windows Azure’s Service Bus to Solve Data Security Issues detailed how to solve data sercurity issues involved in cloud computing. This thesis has been sited in a wikipedia article on…
Using SQL to get the number of occurrences of a character in a string in SQL Server
This SQL Snippet can be used to get the count of a single character, or an entire phrase, in a string. We have a seperate post for doing the same thing in Oracle. Assume you have the string “a,b,c,d,e” and you want the count of commas (“,”) contained in that string. Just use the SQL below:…
Select Sequential Numbers with Oracle SQL
Oracle provides the connect by clause that can be used to specify a relationship between parent rows and child rows. This is used as part of the hierarchical query clause. In general usage, the connect by clause uses the prior keyword to define the relationship. When using the connect by clause, the level pseudocolumn is…
Using SQL to get the number of occurances of a character in a string in Oracle
This SQL Snippet can be used to get the count of a single character in a string using Oracle. We have a seperate post for doing the same thing in SQL Server. Assume you have the string a,b,c,d,e and you want the count of commas. Just use the SQL below. Select length('a,b,c,d,e')-length(replace('a,b,c,d,e',',')) from dual; Running this query returns…
Convert a CSV String into Rows using OracleSQL
The is the Oracle version of an SQL Solution which can transform a string of CSV values into rows, with one row per value. The SQL snippet uses a delimited string, and will convert this string to rows using the delimiter. Assume you have a Comma Seperated Value (CSV) string such as: a,b,c,d and need to convert it to…
Coprocessors: The progression of the offloading of processing requirements.
A coprocessor is an additional processor that augments the Central Processing Unit (CPU). In some cases, coprocessors provide additional functionality not offered by the primary processor. In other cases, the coprocessor only offloads processor intensive tasks, from the primary processor, in order to increase performance. The use of a coprocessor increases system performance by freeing…
Shortest Path Algorithm Comparison
This post will compare two of the popular algorithms used to attack this shortest-path problem in graph theory, Floyd’s algorithm and Dijkstra’s algorithm. I will briefly describe each algorithm, compare the two, and then provide guidelines for choosing between them. In addition, I will describe the results of test cases I ran on both algorithms….