In this chapter, you learned how to use expressions, including using literals, operators, columns, and built-in functions to create expressions. You learned how to use each and that you can use them all together to create expressions.
You learned about the different types of built-in functions, including string, numeric, datetime, and advanced functions, which include casting and converting to other data types. There are many different kinds of string, numeric, and datetime built-in functions. They help you to work with expressions to ensure they are in the format and data type that you want. You also learned how to work with NULL values. Additionally, you learned how indexing might be affected by built-in functions.
Next, you learned how to use statistical functions, including how to get and use variance and standard deviation with the STDDEV and VARIANCE functions...
