Where is it? Seriously, where is it?
We’ve all had the experience of trying to locate a specific column name or wanting to see the meta-data for columns in a specific or multiple tables. By reading the information schema tables we can see the meta-data and find all occurences of the column in the database. This information can be quite useful when needing to join columns and finding some hidden relationships.
“Why doesn’t this function exist?”
We have all had the situation where there is a need for a little custom function to modify strings or do simple math on a column. Today I am going to show how to create a User Defined Function (UDF) in Microsoft SQL.
I’m not gonna write you a love song – Sara Bareilles
A question I’ve always wondered is their a magic formula for creating a number one song. Many song writers are prolific however their song doesn’t necessarily have commercial success. It may be difficult to quantify how the musical composition relates to the song’s success. However I am going to make an attempt at evaluating the lyrics of songs to determining if we can accurately predict if a song will be commercially successful.
To obtain the data I am going to use Beautiful Soup and a few other packages to scrap the content from the websites.
The first step is getting the list of the songs by the artist. I am using the website http://www.azlyrics.com to obtain the list of songs and the lyrics for the songs.
The data created in the previous step needs a little bit of cleaning up before we can get into the model building. It is a common step that needs to be undertaken to ensure that the data can be loaded into models without any issues.
Steps for Preparing the Data
In this step, I will look at the data to see if we can do any feature engineering. And then I will edit the data for the model, train multiple models, evaluate the best model and then test the model. Let’s get started.
Steps for Creating the Model
If we want to compute the minimum number of flight segments between a starting city and target city, we can construct an undirected graph. In the graph the nodes represent cities and the edges represent the flight segments. We can count the number of segments to determine the shortest distance.
The following can be applied to any situation in finding the shortest path. It is an implementation of the breadth first search algorithm.
See code below.
One of the key issues facing film production companies is, will the production company make a profit from a movie. It is assumed that favorable audience reviews will in-turn lead to higher ticket sales or DVD sales, both items directly affect a movie’s profitability.
The analysis will look at what attributes lead to a higher average audience review score on the public website, Rotten Tomatoes
Spoiler Alert The analysis creates a model that is close, but isn’t 100% confident.
One of the more interesting aggregation functions is RANK. After doing a standard SELECT and GROUP BY; you can then have SQL rank the results using an aggregated value from another column.
Let’s dive in and look at how RANK works and what can it do for us.
Previous to Oracle 12c limit the number of rows returned usually meant encapsulating the query as a subquery. It wasn’t particularly nice looking and was out of alignment with other relational database query languages.
MySQL uses the LIMIT operator and Microsoft T-SQL uses the TOP operator. In Oracle 12c, Oracle introduced the FETCH FIRST operator. Let’s see how it works.
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