Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Databases SQL Basics Finding the Data You Want Filtering on More than One Condition

reggaeshark
reggaeshark
8,542 Points
Posted by reggaeshark
reggaeshark
8,542 Points

There should be a mention of using brackets for ordering.

in my opinion a key missing information

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

If by "brackets" you mean "parentheses" (sometimes called "round brackets" in the UK), they are not necessary in simple expressions. Even in complex expressions they would typically only be used when it is necessary to change the default precedence of evaluation. This concept was probably considered beyond the scope of this introductory-level beginner course.

Zimri Leijen
Zimri Leijen
11,835 Points

And what is the default precedence of evaluation?

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Precedence may vary slightly with other manufacturers, but for example here's the order for SQL Server:

  1. ~ (Bitwise NOT)
  2. * (Multiplication), / (Division), % (Modulus)
  3. + (Positive), - (Negative), + (Addition), + (Concatenation), - (Subtraction), & (Bitwise AND), ^ (Bitwise Exclusive OR), | (Bitwise OR)
  4. =, >, <, >=, <=, <>, !=, !>, !< (Comparison operators)
  5. NOT
  6. AND
  7. ALL, ANY, BETWEEN, IN, LIKE, OR, SOME
  8. = (Assignment)