Instruction
Great! You know two ways to concatenate values: the + operator and the CONCAT() function. What is the difference between them?
Think back to using the + operator. When there was a NULL value in one of the joining columns, what was returned? A NULL.
The CONCAT() function converts NULL to an empty string. Let's see this in an example. Remember, if any of the column you work with is NULL-able (i.e., can contain NULL) you should use the CONCAT() function and not the + operator.
Exercise
You see Vacum2010 as the product name, though there was a NULL value in the Type column.
Run the template and look at the result.



