Sams Teach Yourself SQL in 21 Days, Fourth Edition

Bonus Day 2

Quiz

1:	With embedded functions, which function is resolved first, the innermost function or the outermost function?
A1:	The innermost function.
2:	Are NULL values considered when an average of values in a column is calculated?
A2:	NULL values are not recognized by aggregate functions.
3:	When you convert bytes to megabytes, why do you divide by 1024 twice?
A3:	There are 1,024 bytes in a kilobyte and 1,024 kilobytes in a megabyte.
4:	What must you do to a value in a Character format before using the value in a calculation?
A4:	You must first convert the character to a Numeric value using a conversion function. Today, we used Oracle's conversion function called TO_NUMBER.

Exercises

1:	Using the emp_tbl table, write a SQL statement using MySQL ...