SQRT (SSIS Expression)
Applies to: 
SQL Server
SSIS Integration Runtime in Azure Data Factory
Returns the square root of a numeric expression.
Syntax
SQRT(numeric_expression)
Arguments
numeric_expression
Is a numeric expression of any numeric data type. For more information, see Integration Services Data Types.
Result Types
DT_R8
Remarks
SQRT returns a null result if the argument is null.
SQRT fails if the argument is a negative value.
The argument is cast to the DT_R8 data type before the square root operation.
Expression Examples
This example returns the square root of a numeric literal. The return result is 12.
SQRT(144)
This example returns the square root of an expression, the result of subtracting values in the Value1 and Value2 columns.
SQRT(Value1 - Value2)
This example returns the length of the third side of a right triangle by applying the SQUARE function to two variables and then calculating the square root of their sum. If Side1 contains 3 and Side2 contains 4, the SQRT function returns 5.
SQRT(SQUARE(@Side1) + SQUARE(@Side2))
Note
In expressions, variable names always include the @ prefix.