| title | POWER (Transact-SQL) | ||
|---|---|---|---|
| description | POWER (Transact-SQL) | ||
| author | MikeRayMSFT | ||
| ms.author | mikeray | ||
| ms.date | 03/13/2017 | ||
| ms.service | sql | ||
| ms.subservice | t-sql | ||
| ms.topic | reference | ||
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| monikerRange | >=aps-pdw-2016 || =azuresqldb-current || =azure-sqldw-latest || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current || =fabric || =fabric-sqldb |
[!INCLUDE sql-asdb-asdbmi-asa-pdw-fabricse-fabricdw-fabricsqldb]
Returns the value of the specified expression to the specified power.
:::image type="icon" source="../../includes/media/topic-link-icon.svg" border="false"::: Transact-SQL syntax conventions
POWER ( float_expression , y )
float_expression
Is an expression of type float or of a type that can be implicitly converted to float.
y
Is the power to which to raise float_expression. y can be an expression of the exact numeric or approximate numeric data type category, except for the bit data type.
The return type depends on the input type of float_expression:
| Input type | Return type |
|---|---|
| float, real | float |
| decimal(p, s) | decimal(38, s) |
| int, smallint, tinyint | int |
| bigint | bigint |
| money, smallmoney | money |
| bit, char, nchar, varchar, nvarchar | float |
If the result does not fit in the return type, an arithmetic overflow error occurs.
The following example demonstrates raising a number to the power of 3 (the cube of the number).
DECLARE @input1 FLOAT;
DECLARE @input2 FLOAT;
SET @input1= 2;
SET @input2 = 2.5;
SELECT POWER(@input1, 3) AS Result1, POWER(@input2, 3) AS Result2; [!INCLUDEssResult]
Result1 Result2
---------------------- ----------------------
8 15.625
(1 row(s) affected)
The following example shows how the float_expression preserves the data type which can return unexpected results.
SELECT
POWER(CAST(2.0 AS FLOAT), -100.0) AS FloatResult,
POWER(2, -100.0) AS IntegerResult,
POWER(CAST(2.0 AS INT), -100.0) AS IntegerResult,
POWER(2.0, -100.0) AS Decimal1Result,
POWER(2.00, -100.0) AS Decimal2Result,
POWER(CAST(2.0 AS DECIMAL(5,2)), -100.0) AS Decimal2Result;
GO [!INCLUDEssResult]
FloatResult IntegerResult IntegerResult Decimal1Result Decimal2Result Decimal2Result
---------------------- ------------- ------------- -------------- -------------- --------------
7.88860905221012E-31 0 0 0.0 0.00 0.00
The following example returns POWER results for 2.
DECLARE @value INT, @counter INT;
SET @value = 2;
SET @counter = 1;
WHILE @counter < 5
BEGIN
SELECT POWER(@value, @counter)
SET NOCOUNT ON
SET @counter = @counter + 1
SET NOCOUNT OFF
END;
GO [!INCLUDEssResult]
-----------
2
(1 row(s) affected)
-----------
4
(1 row(s) affected)
-----------
8
(1 row(s) affected)
-----------
16
(1 row(s) affected)
Examples: [!INCLUDEssazuresynapse-md] and [!INCLUDEssPDW]
The following example shows returns POWER results for 2.0 to the 3rd power.
SELECT POWER(2.0, 3); [!INCLUDEssResult]
------------
8.0
decimal and numeric (Transact-SQL)
float and real (Transact-SQL)
int, bigint, smallint, and tinyint (Transact-SQL)
Mathematical Functions (Transact-SQL)
money and smallmoney (Transact-SQL)