Amazing!

Now let's summarize what we've learned in this section:

We know that:

• Computations using floating point numbers are not always exact. Use the DECIMAL or MONEY data types for all money columns and whenever precision matters.
• Dividing two integers is integer division, which is not always accurate. Use CAST(column AS TYPE) to avoid it.
• Avoid division by zero.

We've also learned some useful functions:

• The modulo operator (expressed as x % y) returns the remainder of the division of x by y.
• ROUND(x,p) rounds x up to the nearest whole integer or to the specified number of decimal digits (p).
• CEILING(x) always rounds up to the nearest integer value.
• FLOOR(x) always rounds down to the nearest integer value.
• ABS(x) returns the absolute value of x.
• SQRT(x) returns the square root of x.

The queries we've written so far have been fairly simple. Let's test your knowledge with some more advanced exercises.