Method convert_str_value

sql/item.cc:2052–2091

*/

bool Item_param::convert_str_value(THD *thd)
{
  bool rc= FALSE;
  if (state == STRING_VALUE || state == LONG_DATA_VALUE)
  {
    if (value.cs_info.final_character_set_of_str_value == NULL ||
        value.cs_info.character_set_of_placeholder == NULL)
      return true;
    /*
      Check is so simple because all charsets were set up properly
      in setup_one_conversion_function, where typecode of
      placeholder was also taken into account: the variables are different
      here only if conversion is really necessary.
    */
    if (value.cs_info.final_character_set_of_str_value !=
        value.cs_info.character_set_of_placeholder)
    {
      rc= thd->convert_string(&str_value,
                              value.cs_info.character_set_of_placeholder,
                              value.cs_info.final_character_set_of_str_value);
    }
    else
      str_value.set_charset(value.cs_info.final_character_set_of_str_value);
    /* Here str_value is guaranteed to be in final_character_set_of_str_value */

    max_length= str_value.numchars() * str_value.charset()->mbmaxlen;

    /* For the strings converted to numeric form within some functions */
    decimals= NOT_FIXED_DEC;
    /*
      str_value_ptr is returned from val_str(). It must be not alloced
      to prevent it's modification by val_str() invoker.
    */
    str_value_ptr.set(str_value.ptr(), str_value.length(),
                      str_value.charset());
    /* Synchronize item charset with value charset */
    collation.set(str_value.charset(), DERIVATION_COERCIBLE);
  }
  return rc;
}


bool Item_param::basic_const_item() const