All fields should be treated as read-only unless explicitly stated otherwise.
| * | 
    The driver must set this during SKEL_handle_preparer().  | 
| ** | 
    This item is for use by the driver; the intended usage is to store a pointer (during SKEL_handle_factory()) to whatever instance data is required to maintain a connection to the database.  | 
| *** | 
    This is set by PDO after the statement has been executed for the first time. Your driver can inspect this value to determine if it can skip one-time actions as an optimization.  | 
| **** | 
    Discussed in more detail in Fleshing out your skeleton.  | 
| ***** | 
    Your driver is responsible for setting this field to the number of columns available in a result set. This is usually set during SKEL_stmt_execute() but with some database implementations, the column count may not be available until SKEL_stmt_fetch() has been called at least once. Drivers that implement SKEL_stmt_next_rowset() should update the column count when a new rowset is available.  | 
| ****** | 
    PDO will allocate this field based on the value that you set for the column count. You are responsible for populating each column during SKEL_stmt_describe(). You must set the precision , maxlen , name , namelen and param_type members for each column. The name is expected to be allocated using emalloc(); PDO will call efree() at the appropriate time.  |