Scenario:
Let’s say we are extracting data from flat file or from Database table. Few of the columns have Null values. In our destination we do not want to insert these values as NULL. We want to replace Null values with “Unknown” for character type columns and 0 ( Zero) for integer type columns.
Solution:
If we are extracting data from Database table then we can use IsNULL function and replace with required values but If we are extracting data from flat file then we cannot use this function and we have to use some transformation in SSIS to perform this operation.
In derived column transformation, there are different types of functions and operators are available those can help us to achieve this required results
- Mathematical Function
- String Functions
- Date/Time Functions
- Null Functions
- Type Casts Functions
- Operators
Here are the steps how we will be replacing Null values by using Derived column Transformation
Step 1:
Create connection to your flat file by using Flat File Source. I have used below data in text file for this example.Notice SaleAmount for Italy,andy is missing and SalePerson is missing for Brazil,,200
CountryName,SalePersonName,SaleAmount
uSA,aamir shahzad,100
Italy,andy,
UsA,Mike,500
brazil,Sara,1000
INdia,Neha,200
Brazil,,200
Mexico,Anthony,500
Step 2:
Bring Derived Column Transformation in Data Flow Pane and then connect Flat File Source to it. By double clicking derived column transformation, write expressions as shown below for SSIS 2008 and SSIS 2012.
SSIS 2012 introduced new function REPLACENULL that we can use and get the required results but in previous versions of SSIS, we have to use if else expressions with ISNULL Function to achieve this.
How you will read this expression
ISNULL(SalePersonName) ? "Unknown" : SalePersonName
IF (?) SalePersonName is Null then “Unknown” Else (:) Column Value itself( SalePersonName)
SSIS 2008 Derived Column Expression
