Selecting string literals in PostgREST query

[taimoorzaeem]

Background

Someone reached out to me privately to ask this. I am opening this for public discussion.

Problem

They said:

I just a have a quick question that has probably been mentioned in the docs but
for the life in me I cannot find it.

How do I deal with hardcoded values, like if I want to select something
from a table and then add a hardcoded value to it, in postgresql I would
do it as:

SELECT somecolumn, 'hardcodedvalue' as hardcodedname FROM sometable

where I would another column (or key as json) with the value of
'hardcodedvalue' and key hardcodedname.

I tried with something like this
sometable?select=somecolumn,hardcodedname:'hardcodedvalue' but that
obviously didnt work.

[steve-chavez]

Easiest way would be a computed field.

Maybe the docs can also add https://www.postgresql.org/docs/current/ddl-generated-columns.html as an alternative.

sometable?select=somecolumn,hardcodedname:'hardcodedvalue' but that
obviously didnt work.

I don't think we should do that at the API level. How would OpenAPI look like if we allowed to change a resource row type at runtime?

Also I guess it'd be easier to add that at the client level?

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Sidenote: I recall several of these cases over the years, we should add a Limitations section to https://docs.postgrest.org/en/v16/references/api/url_grammar.html.