maulin

Class on the 24th

Well I missed class on the 24th right before thanksgiving. I was wondering what we did in class that day apart from what was scheduled. Was there any important points Bud made? How hard is it to add data into a database via webpages? I also wanted to know if anyone had thought or tried implementing RSS into their projects. I dont know how to get about starting that.

Questions about project 2

I know we barely got done submitting project 1 on Mon and here I am asking questions about project 2. Its just that if you look at it there aint so much time given the fact that theres a week of thnksgiving and finals right around the time project 2 is due. So I was reading the requirements for Project 2 and I thought some of the things were unclear. It says that the idea is pretty much open as to what language we can use etc to publish our database online. Do we have to create like an online front-end for our database like forms or something so that people anywhere can input into the database? I guess things will get cleared when Bud talks about the project in class.

Explanation of XML

Personally I thought XML was pretty confusing and after hearing what Bud said in class I think I'm not alone so I found this link on the web which explains XML and other very common questions asked about XML. Its more like a XML FAQ site. Good source of understanding XML
This webpage answered most of my questions regarding XML. Hope this helps anyone else thats unclear about XML.
I had another rather irrelevant question about SQL. I noticed in many SQL files that the person coding in SQL never used any comments. I thought everyone that wrote programs always commented their work but in many .sql files I did'nt see any comments. I was wondering if this practice is accepted in the programming community.

questions about XML

So now that we're into the second part of the course about XML etc, I think it will be interesting. The lecture on thursday about XML was somewhat confusing. I feel the structure of XML as a language and its syntax is rather confusing as compared to other programming languages. It looks like html but the structure is definitely not. I am a little confused about the use of XML. Its obviously used for web publishing etc but how is it any different than other languages. I am sure Bud talked about this a couple of times in class but for some reason I just cant remember what the differences are. Bud mentioned something about how XML is like a standard language now. What was that about? Just want to clarify my understanding about XML.

chapter 3 from mySql

Well I have been lagging behind in doing the chapters from the mySql book. I was doing chapter 3 in class today and found that some queries were definitely very confusing to write. If we had to write queries for the exam, it would definitely be really stressful. But lucky for us Bud is giving us a multiple choice exam which I dont really know if it is good or bad. I tried reading through some of the scripts posted online and found that reading some queries and understand what the result would be could be pretty difficult. I personally found the queries which use 'grouping', 'having', 'in' etc at the end of chapter 3 kind of hard to understand. I guess the best way to understand these queries is to practice them more and more. Fall break looks like a lot of fun with Bit 320 and other class midterms to study for!!!

queries abt the exam

Well its mid-term week and being a BBA1 definitely makes it a little harder to think of what the exams are going to be like. I wanted to know if there will be a review session for the exam. Would there be any practice exams put up or we would only have to practice the problems given in the coursepack. Will the exam be multiple choice or we would have to make ER models or normalize tables in the exam?

Confusion in ER modeling

I can definitely see what Prof. Bud meant by saying that ER modeling can get confusing. For some reason with me, if i think about the model too much I confuse myself. The point where I have got confused is about the optional versus mandatory entity type partioning Section 4.4. It says that when there is a double line joining from the supertype to the line joining the subtypes, it means that the supertype must have classified as one of the subtype. However, in the next section when it talks about disjoint versus overlapping, it says that unless there is a 'd' under the '-' , the supertype could be classified as more than one subtype. But what if the relationship is represented by a single line i.e. with an optiontal subtyping and a '-' with a 'd' underneath it. Does that mean that the supertype does not need to be classified to either of the two subtypes? I am really confused with this part of ER modeling. Hope someone can help me get a clearer picture of this.

Solution to Exercise 2(normalization)

I have been trying to figure out how the primary key in the "in class normalization exercise #2" consists of CustID, StockSymbol and SellDate. What confuses me is that how can the SellDate be part of the primary key. According to the definition, the primary key cannot have a null value i.e. it must have a value at all times. However, suppose a customer has not sold his stock as yet, the sellDate will be null. Hence i feel that SellDate cannot be part of the primary key. But then again, without SellDate, we cannot get the SellPrice. Now, on the first page of the answers under "Removed derived data", the 3rd bullet points out that the field Sold is a derived data. This is true but I feel removing this field may not be appropriate. If we keep this field which will have a boolean value, then it will tell us if the stock was sold and if that is true, then we will get the SellDate and SellPrice. Thus we can actually make the Sold field part of the primary key which will always have a value. Am a little confused with this solution and was wondering if anyone agreed to it. If so could you please explain the logic behind it.
I tried linking this solution from the course website but i dont think it's posted online.

test post

This is a test post

this is a test post

this is pretty confusing