mlisting">
ereport(ERROR,
        errcode(ERRCODE_AMBIGUOUS_FUNCTION),
        errmsg("function %s is not unique",
               func_signature_string(funcname, nargs,
                                     NIL, actual_arg_types)),
        errhint("Unable to choose a best candidate function. "
                "You might need to add explicit typecasts."));
</pre><p>
    This illustrates the use of format codes to embed run-time values into
    a message text.  Also, an optional <span class="quote">“<span cl