Method field_decimal

sql/sql_analyse.h:156–161

  int bin_size;
public:
  field_decimal(Item* a, select_analyse* b) :field_info(a,b)
  {
    bin_size= my_decimal_get_binary_size(a->max_length, a->decimals);
    init_tree(&tree, 0, 0, bin_size, (qsort_cmp2)compare_decimal2,
              0, 0, (void *)&bin_size);
  };

  void	 add();
  void	 get_opt_type(String*, ha_rows);