Private Sub BtPostgres_Click()

    Dim cn As ADODB.Connection
    Dim rs As ADODB.Recordset
    
    Dim ADO_Connect As ADODB.Connection
    Set ADO_Connect = New ADODB.Connection
    
    With ADO_Connect
        .ConnectionString = "DSN=book"
        .Mode = adModeReadWrite
        .Open
    End With

    'Create an instance of the ADO Recordset class,
    'and set its properties
    Set rs = New ADODB.Recordset
    With rs
       Set .ActiveConnection = ADO_Connect
       .Source = "select * from f_book();"
       .CursorLocation = adUseClient
       .CursorType = adOpenStatic
       .LockType = adLockOptimistic
       .CursorType = adOpenStatic
       .Open
    End With
    
    'Set the form's Recordset property to the ADO recordset
    Set Me.BookList.Form.Recordset = rs
    Set rs = Nothing
    Set cn = Nothing

End Sub

CREATE OR REPLACE FUNCTION public.f_book(
	)
    RETURNS SETOF tbl_book 
    LANGUAGE 'sql'

    COST 100
    VOLATILE 
    ROWS 1000
AS $BODY$
    SELECT * FROM "tbl_book";
$BODY$;

-- Table: public.tbl_book

-- DROP TABLE public.tbl_book;

CREATE TABLE public.tbl_book
(
    id integer NOT NULL DEFAULT nextval('tbl_book_id_seq'::regclass),
    book_name character varying(30) COLLATE pg_catalog."default",
    CONSTRAINT tbl_book_pkey PRIMARY KEY (id)
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE public.tbl_book
    OWNER to postgres;

select * from f_books('18');