I have been focusing primarily on w3school's SQL tutorial. So far, I have completed through the DELETE statement. I have learned how to use the SELECT and SELECT DISTINCT statements in conjunction with FROM and COUNT, as well as WHERE. Furthermore, I am now familiar with the operators used by the WHERE condition (<, >, =, and so on) as well as how to use multiple conditions in one expression. Additionally, I am now comfortable with the ORDER BY statement (and how it defaults to ascending order) as well as the INSERT INTO statement and the accompanying VALUES statement. I understand that NULL is not 0 or " " but the language's recognition of a field in a record which was not given a value, and I understand how to search for both null and non-null fields using IS NULL and IS NOT NULL. Lastly, I learned about the UPDATE statement and how its use is dependent on the WHERE clause, as well as how the DELETE statement can be used with conditions.
In watching Professor Widom's videos, I found her visual aids helpful in constructing my thinking as to how an expression should be formed. For example, in an expression such as:
SELECT attributes (3)
FROM relations (1)
WHERE condition (2)
You would want to think first of the FROM statement, then the WHERE statement, and lastly the SELECT statement.
However, I wish that I knew how to follow along with her videos on my laptop as I feel that many of the more confusing aspects of SQL would be made less so were I to directly interact with them.