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
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.