Re: Fixing set-returning functions are not allowed in UPDATE after upgrade to Postgres 12

["David G. Johnston" <david.g.johnston@xxxxxxxxx>]

On Thu, Apr 2, 2020 at 11:38 PM Andrus <kobruleht2@xxxxxx> wrote:

Hi!

>Simply replace
>   SET col = unnest(array_value)
>with
>
>   SET col = array_value[1]

I tried

 

update temprid set
    ContactFirstName =xpath(
         '/E-Document/Document/DocumentParties/BuyerParty/ContactData/ContactFirstName/text()',x)[1]::text

Parens around the function call _expression_ are required per the syntax documentation for array subscript access:

https://www.postgresql.org/docs/current/sql-expressions.html#SQL-EXPRESSIONS-SUBSCRIPTS  

update temprid set

    ContactFirstName =(xpath(
         '/E-Document/Document/DocumentParties/BuyerParty/ContactData/ContactFirstName/text()',x))[1]::text  

David J.