无法在sqlite3中获取绑定参数名称

代码: (重新生成问题的最小代码)

var db: OpaquePointer? = nil
var rc: Int32 = 0
rc = sqlite3_open("test.db", &self.db)
if rc != SQLITE_OK
{
    print("cant open")
}
var statement: OpaquePointer? = nil
let sql = "insert into testtable values(?123);"
rc = sqlite3_prepare_v2(db, sql, -1, &statement, nil)
if rc != SQLITE_OK
{
    print("cant prepare")
}
print(String(cString: sqlite3_bind_parameter_name(statement, 1))) // returns nil
sqlite3_finalize(statement)
sqlite3_close(db)

@AAA :AAA $AAA 但我明白了 nil ?123 ( ?NNN website 我应该得到 像 String