9. Operator Precedence
* / + -
• Multiply and division take priority over addition and subtraction
• Operators of the same priority are evaluated from left to right.
• Parentheses are used to force prioritized evaluation.
12. Null Values
NULL Value:
• Unavailable Value
• Unassigned Value
• Unknown Value
• Inapplicable Value
Null Value
13. Null Values in Arithmetic Expression
Arithmetic expression
containing a Null Value
evaluates to null
14. Column Aliases
• Renames a column heading
• Aliases immediately follows column
names.
• Optional AS keyword between column
name and aliases.
• Requires double quotation marks if it
contains spaces or special characters or
is case sensitive
16. Assignment 02
1. Display the name concatenated with the
job, separated by comma and space also
name the column with Employee and Title.
2. Display the name and job of the employee
, they belongs to department number 20.
3. Display the name and salary of the person
whose job title is MANAGER.