Expose Column Metadata on `PostgresRowSequence`

[SteveLauC]

Hey, thanks for providing and maintaining this lib!

I would like to know how to get the column names of a query result. I do take a look at the doc, but it looks like this is not covered.

Reading the code, both PostgresRowSequence and PreparedQuery store column metadata:

postgres-nio/Sources/PostgresNIO/New/PostgresRowSequence.swift

Line 14 in ca70d8c

let columns: [RowDescription.Column]

postgres-nio/Sources/PostgresNIO/Connection/PostgresDatabase+PreparedQuery.swift

Line 32 in ca70d8c

let underlying: PSQLPreparedStatement

but the fields are private, and there are no public interfaces that can be used to get the information.

Thanks!

[fabianfett]

Hi 👋 ,

you can get the information in the following way:

for try await row in rowSequence {
    for cell in row {
        cell.columnName // this is what you are looking for
    }
}

Hope that helps.

[SteveLauC]

Hi, thanks for the response!

If the query returns 0 rows, it looks like this method would not work? For example select * from pg_class where false

[fabianfett]

That is true, I'm happy to accept a pr that exposes the column metadata on the row sequence. However we will need a new type for that. RowDescription.Column is required to stay internal.

[SteveLauC]

Thanks for confirming this! I will draft a PR for that:)