Instruction
Okay, let's begin. First, we'll need a new operator: ||. These two vertical bars are the concatenation operator, i.e., they join two or more text values (or strings, which is another name for text). If you write the following:
SELECT first_name || last_name FROM copywriter;
The result for first_name = 'Kate' and last_name = 'Gordon' will be KateGordon, all in a single column. Quite simple, right?
Of course we want the first and last name separated with a space. Here's how you do it:
SELECT first_name || ' ' || last_name FROM copywriter;
Note that you use apostrophes for specific constant text values (a space in our example: ' '), but you don't use apostrophes for column names (first_name, last_name). The operator || can be used as many times as you need in a single query.
Exercise
For each item, select its name, type, and in the third column named slogan_type both values joined by a dash ('-'):
name-type
Observe that if the name or type is NULL, then the slogan_type is also NULL.
Stuck? Here's a hint!
Use the following expression:
name || '-' || type
