Hi Gary,
Sounds like you’re creating a wedding mailing list or similar. I would use nested IF logic: https://support.airtable.com/hc/en-us/articles/221564887-Nested-IF-formulas
Change the field where you want the concatenated result to a formula and try this one:
IF({Last Name 2} = BLANK(), {First Name 1} & " " & {Last Name 1}, IF({Last Name 1}={Last Name 2}, {First Name 1} & " & " &{First Name 2}& " " & {Last Name 1}, {First Name 1} & " " &{Last Name 1} & " & " &{First Name 2} & " " &{Last Name 2}))
Looking at your criteria, I see some interesting patterns that can be used to simplify the formula a bit.
- First Name-1 is always there, so we can start the formula with that no matter what.
- Last Name-1 is always there, though it may have First Name-2 before it based on one condition.
With those in mind, here’s an alternative formula:
{First Name-1} &
IF(
AND({First Name-2}, NOT({Last Name-2})),
" & " & {First Name-2}
) &
" " & {Last Name-1} &
IF(
AND({First Name-2}, {Last Name-2}),
" & " & {First Name-2} & " " & {Last Name-2}
)

Looking at your criteria, I see some interesting patterns that can be used to simplify the formula a bit.
- First Name-1 is always there, so we can start the formula with that no matter what.
- Last Name-1 is always there, though it may have First Name-2 before it based on one condition.
With those in mind, here’s an alternative formula:
{First Name-1} &
IF(
AND({First Name-2}, NOT({Last Name-2})),
" & " & {First Name-2}
) &
" " & {Last Name-1} &
IF(
AND({First Name-2}, {Last Name-2}),
" & " & {First Name-2} & " " & {Last Name-2}
)

Thank you VERY much.
Gary Nelson