Another method for validating a column is to refer to a lookup containing a list of allowed values that can be stored in any format (file, table, XML for example).
Open the job
jo_cook_ch03_0050_tMapValuesInLookup.You will see that there are two inputs to the tMap: customer and country.
tMap, and drag the field
countryOfBirthfrom the customer input to the
countryNamefield in the country input. This will create a key link, as shown in the following screenshot: