Outputting Data on Data Extension Using Lookup and Output AmpScript Functions

Question

I want to output some data and using 'Output' and 'Lookup' functions.

If my DE fields looks like this:

Name           Data Type.      Length. Primary Key. Nullable. Default Value
FIRST NAME     Text            50
LAST NAME      Text            50
EMAIL.         EmailAddress.   254.     x

What is the correct AmpScript to output someone's first name?

My AmpScript currently looks like this. I have a feeling my 4th argument is incorrect b/c I"m not sure what is the "Value that identifies the row to retrieve" according to docs.

%%[

var @firstName
set @firstName = Lookup("DE__Test", "FIRST NAME", "EMAIL", EMAIL)

Output(Concat("First Name: ", @firstName))

]%%

Answer 1

The fourth argument is like the field name for the first condition of a where-clause in a SQL statement. You could write your lookup in pseudocode like this:

Retrieve FIRST NAME from DE__Test where EMAIL = EMAIL

Also, you don't need to use a lookup if DE__Test is the sending data extension.

You can reference the send context column names directly or assign them to variables:

%%[

var @firstName
set @firstName = AttributeValue("First Name")

output(concat("<br>Hi, ", @firstName))

]%%