Tutor profile: Gabrielle L.
Subject: SQL Programming
Can you explain JOINS and how they work?
JOINS are a way of combining or 'joining' information from two or more different tables that have a column in common. So your SELECT statement will list the column that you want in your result, your FROM statement will list the two tables that you want to JOIN and the column that connects them. SELECT column1, column2, column3 FROM table1 JOIN table2 ON table1.column = table2.column; There are several different types of JOINS: INNER JOIN, LEFT JOIN, RIGHT JOIN, and OUTER JOIN. The type of JOIN that you chose to use in your will determine what data will be returned in your results. Picture, if you can, a venn diagram where the two larger circles are your two tables. An Outer JOIN would consist of all the information on the diagram contains (both circles and the area where the intersect). A LEFT JOIN would consist of all the information contained within the circle on the left (table1) and the intersection. A RIGHT JOIN would consist of the information from the right circle (table2) and the intersection. An INNER JOIN would only contain the information from the intersection. How about an example: Let's say that you want all of the information from the first table and where table1 and table2 overlap. You would use a LEFT JOIN. You will SELECT what columns you want in the results and then use a LEFT JOIN in the FROM statement, including what column they have in common to connect them. SELECT column1, column2, column3 FROM table1 LEFT JOIN table2 ON table1.column = table2.column; All that has changed is the type of JOIN being used, but this small change ensures that only the information from table1 and the intersection will be returned in your results.
Subject: Library and Information Science
Can you explain what metadata is?
Metadata is information about information, which I know is very ambiguous, but I think a couple of examples might help. Let's you have a picture that was taken at your 5th birthday party of you blowing out candles on your birthday cake. The picture holds information about your birthday party, the year was taken, how old you were, etc., but what information do we have about the picture itself? What kind of camera was it taken on? A digital camera, a Polaroid, a disposable camera? Who took the photo? Who has the rights to the photo? Let's say that it's digital, how big are the pixels? what is the resolution? exposure? saturation? Was there a filter used when the initial picture was taken? What about after the picture has been uploaded? Was the photo edited at all? Compressed? Did the format of the digital copy (.png, .jpeg, .svg) change? Did you put any filters on it? Change the color, contrast, or saturation? Lets say you printed the photo, now you have two photographs, the digital photo and the physical copy. That physical copy will have it's own metadata (size, medium, color, etc.). Ok, that was a very big example but it shows you how much information there is about information. Normally when collecting metadata we follow a schema, which is an outline of what metadata to collect. There are several different schemas: Dublin Core, PB Core, PREMIS, METS, CDWA, and many, many more. While metadata can be very overwhelming there are tools that can help you such as data dictionaries for the schema you are working with and the controlled vocabulary that they choose to use (LOC, ISO, etc.)
How do I take a proper breath for singing and how do I use that breath?
There are two primary muscle groups that are used to fill your lungs with air, your diaphragm, which sits just below your lungs, and your intercostals, which are the muscles between your ribs. When you contract these muscles your body fills with air. What many people don't realize is that you don't just breath in through your stomach, you breath into your front, sides, and back, as well as above and below. When breathing in you should feel these muscles work. It might be a good idea to place your hands on your sides or on your back to feel these muscles when they are contracting. When singing you control that breath by using the muscles that surround your lungs, the intercostals and diaphragm, as well as the abdominal wall which surrounds your stomach. There are two ways of thinking about how to use these muscles: You can either focus energy on pushing the muscles outward, trying to expand that bubble of air inside of you, or you can pull your muscles inward to control how much air is used when.
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