OR (Transact-SQL)

Artykuł
12/08/2014

Combines two conditions. When more than one logical operator is used in a statement, OR operators are evaluated after AND operators. However, you can change the order of evaluation by using parentheses.

Ikona łącza do tematu Transact-SQL Syntax Conventions

Składnia

boolean_expression OR boolean_expression

Arguments

boolean_expression
Is any valid expression that returns TRUE, FALSE, or UNKNOWN.

Result Types

Boolean

Result Value

OR returns TRUE when either of the conditions is TRUE.

Uwagi

The following table shows the result of the OR operator.

	TRUE	FALSE	UNKNOWN
TRUE	TRUE	TRUE	TRUE
FALSE	TRUE	FALSE	UNKNOWN
UNKNOWN	TRUE	UNKNOWN	UNKNOWN

Examples

The following example uses the vEmployeeDepartmentHistory view to retrieve the names of Quality Assurance personnel who work either the evening shift or the night shift. If the parentheses are omitted, the query returns Quality Assurance employees who work the evening shift and all employees who work the night shift.

USE AdventureWorks2012;
GO
SELECT FirstName, LastName, Shift 
FROM HumanResources.vEmployeeDepartmentHistory
WHERE Department = 'Quality Assurance'
   AND (Shift = 'Evening' OR Shift = 'Night');

Here is the result set.

FirstName LastName Shift

------------ ---------------- -------

Andreas Berglund Evening

Sootha Charncherngkha Night