func mustPrepare(t testing.TB, conn *pgx.Conn, name, sql string) *pgx.PreparedStatement {
	ps, err := conn.Prepare(name, sql)
	if err != nil {
		t.Fatalf("Could not prepare %v: %v", name, err)
	}

	return ps
}
Beispiel #2
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// afterConnect creates the prepared statements that this application uses
func afterConnect(conn *pgx.Conn) (err error) {
	_, err = conn.Prepare("getUrl", `
    select url from shortened_urls where id=$1
  `)
	if err != nil {
		return
	}

	_, err = conn.Prepare("deleteUrl", `
    delete from shortened_urls where id=$1
  `)
	if err != nil {
		return
	}

	// There technically is a small race condition in doing an upsert with a CTE
	// where one of two simultaneous requests to the shortened URL would fail
	// with a unique index violation. As the point of this demo is pgx usage and
	// not how to perfectly upsert in PostgreSQL it is deemed acceptable.
	_, err = conn.Prepare("putUrl", `
    with upsert as (
      update shortened_urls
      set url=$2
      where id=$1
      returning *
    )
    insert into shortened_urls(id, url)
    select $1, $2 where not exists(select 1 from upsert)
  `)
	return
}