An operator is a symbol that represents an action performed on one or more expressions.

There are three types of SQL operators:

Arithmetic operators are used to combine numeric expressions arithmetically to form other numeric expressions.

The following are the valid arithmetic operators (in descending order of precedence):

Unary operators group from right to left, while binary operators group from left to right. Use the unary minus (-) to reverse the algebraic sign of a value.

To force a desired order of evaluation, use parentheses. For example:

is an expression in which the parentheses force the addition operator (+) to take precedence over the multiplication operator (*).

Comparison operators compare two expressions. SQL includes the following comparison operators:

The <> operator can also be specified as != or ^=.

All comparison operators are of equal precedence.

The equal sign (=) also serves as the assignment operator in assignment operations (see Assignment Operations).

SQL has three logical operators, shown in order of precedence:

Use parentheses to change the order of evaluation. For example, the following expression:

is evaluated as:

When parentheses are used as follows:

OpenROAD evaluates (exprA or exprB) first, then uses the AND operator for the result with exprC.

Parentheses can also be used to change the default evaluation order of a series of expressions combined with the same logical operator. For example, the following expression:

is evaluated as:

To change this default left-to-right grouping, use parentheses as follows:

The parentheses direct OpenROAD to use the AND operator for exprB and exprC, then use the AND operator for that result with exprA.