Method Item_string

sql/item.h:2089–2108

Create from a string, set name from the string itself. */

public:
  /* Create from a string, set name from the string itself. */
  Item_string(const char *str,uint length,
              const CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE,
              uint repertoire= MY_REPERTOIRE_UNICODE30)
    : m_cs_specified(FALSE)
  {
    str_value.set_or_copy_aligned(str, length, cs);
    collation.set(cs, dv, repertoire);
    /*
      We have to have a different max_length than 'length' here to
      ensure that we get the right length if we do use the item
      to create a new table. In this case max_length must be the maximum
      number of chars for a string of this type because we in Create_field::
      divide the max_length with mbmaxlen).
    */
    max_length= str_value.numchars()*cs->mbmaxlen;
    item_name.copy(str, length, cs);
    decimals=NOT_FIXED_DEC;
    // it is constant => can be used without fix_fields (and frequently used)
    fixed= 1;
  }
  /* Just create an item and do not fill string representation */
  Item_string(const CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
    : m_cs_specified(FALSE)