An Oracle Programmatic and General Reference
 Operators
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Oracle supports a number of built in operators that fall into basic categories—simple arithmetic operators, comparison operators, logical operators, and operators that are used in select statements. In Oracle 9, support for User Defined Operators was also added.
Arithmetic Operators
Table 11. Arithmetic Operators
Operator 
What it does 

+ (unary) – (unary) 
Specifies a positive number or expression Specifies a negative number or expression 
+ (binary)  (binary) 
Addition Subtraction 
* / 
Multiplication Division 
Logical Operators
Table 12. Logical Operators
Operator 
What it does 

 
Concatenates two character (string) values 
NOT 
Reverses the meaning of another logical expression's result 
OR 
Logical OR—True if any are true, false else 
AND 
Logical AND—True if all are true, else false 
Comparison Operators
Table 13. Comparison Operators
Operator 
What it does 

= 
true if two expressions are equal 
!= ^= = <> 
logically equivalent—true if two expressions are not equal 
> 
True if left expression is greater than right expression 
>= 
True if left expression is greater than or equal to right expression 
< 
True if left expression is less than right expression 
<= 
True if left expression is less than or equal to right expression 
IN 
Is equal to any member of a set or subquery 
NOT IN 
Does NOT equal any member of a set or subquery 
ANY, SOME 
True if one or more of the values in the list of expressions or subquery satisfies the condition 
ALL 
True if all of the values in the list of expressions or subquery satisfies the condition 
BETWEEN x AND y 
True if greater than or equal to x and less than or equal to y (can be reversed in meaning with NOT) 
EXISTS 
True if the subquery returns at least one row (can be reversed in meaning with NOT) 
LIKE pattern [ESCAPE 'c'] 
'True if expression or subquery matches pattern. '%' matches any sequence of characters, '_' matches any single character. If ESCAPE is used, the character 'c' causes the character following to be taken literally (can be reversed in meaning with NOT). 
IS NULL 
TRUE if the value is NULL (can be reversed in meaning with NOT) 
Select Operators
Also called SET operators
Table 14. Select Operators (Sets)
Operator 
What it does 

UNION 
This combines the results of two queries and returns the set of distinct rows returned by either query 
UNION ALL 
This combines the results of two queries and returns all rows returned by either query, including duplicates 
INTERSECT 
This combines the results of two queries and returns the set of distinct rows returned by both queries 
MINUS 
This combines the results of two queries and returns the distinct rows that were in the first query, but not in the second 
Table 15. Other Select Operators
Operator 
What it does 

(+) 
Denotes that the preceding column is an outer join 
* 
Wildcard operator. Equals all columns in a select statement 
PRIOR 
Denotes a parentchild relationship in a treestructured query 
ALL 
Include all duplicate rows in a query (the default) 
DISTINCT 
Eliminate duplicates in a result set 
Precedence
Oracle evaluates expressions based on the order of precedence. Parentheses () override normal precedence. Lines are evaluated left to right for operators of equal precedence if there are no parentheses to override that order.
SQL Operator Precedence
+ – 
Unary arithmetic operators 
PRIOR operator 
* / 
Arithmetic operators 

+ – 
Binary arithmetic operators 
 character operator 
All comparison operators
NOT 
Logical operator 
AND 
Logical operator 
OR 
Logical operator 
Arithmetic Operator Precedence
+ – 
Unary 
* / 

+ – 
Binary 