LN (SSIS Expression)
Applies to: 
SQL Server
SSIS Integration Runtime in Azure Data Factory
Returns the natural logarithm of a numeric expression.
Syntax
LN(numeric_expression)
Arguments
numeric_expression
Is a valid non-zero and non-negative numeric expression.
Result Types
DT_R8
Remarks
The numeric expression is cast to the DT_R8 data type before the logarithm is computed. For more information, see Integration Services Data Types.
If numeric_expression evaluates to zero or a negative value, the return result is null.
Expression Examples
This example uses a numeric literal. The function returns the value 3.737766961828337.
LN(42)
This example uses the column Length. If the column value is 53.99, the function returns 3.9887988442302.
LN(Length)
This example uses the variable Length. The variable must have a numeric data type or the expression must include an explicit cast to a numeric data type. If Length is 234.567, the function returns 5.45774126708797.
LN(@Length)