Commit 47311e8e authored by unknown's avatar unknown
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Fixed bug#16377: result of DATE/TIME functions were compared as strings which 

can lead to a wrong result.

All date/time functions has the STRING result type thus their results are
compared as strings. The string date representation allows a user to skip 
some of leading zeros. This can lead to wrong comparison result if a date/time 
function result is compared to such a string constant.

The idea behind this bug fix is to compare results of date/time functions
and data/time constants as ints, because that date/time representation is 
more exact. To achieve this the agg_cmp_type() is changed to take in the
account that a date/time field or an date/time item should be compared 
as ints.

This bug fix is partially back ported from 5.0.

The agg_cmp_type() function now accepts THD as one of parameters. 
In addition, it now checks if a date/time field/function is present in the
list. If so, it tries to coerce all constants to INT to make date/time
comparison return correct result. The field for the constant coercion is
taken from the Item_field or constructed from the Item_func. In latter case
the constructed field will be freed after conversion of all constant items.
Otherwise the result is same as before - aggregated with help of the
item_cmp_type() function.

From the Item_func_between::fix_length_and_dec() function removed the part
which was converting date/time constants to int if possible. Now this is 
done by the agg_cmp_type() function.

The new function result_as_longlong() is added to the Item class. 
It indicates that the item is a date/time item and result of it can be
compared as int. Such items are date/time fields/functions.

Correct val_int() methods are implemented for classes Item_date_typecast, 
Item_func_makedate, Item_time_typecast, Item_datetime_typecast. All these
classes are derived from Item_str_func and Item_str_func::val_int() converts
its string value to int without regard to the date/time type of these items.

Arg_comparator::set_compare_func() and Arg_comparator::set_cmp_func()
functions are changed to substitute result type of an item with the INT_RESULT
if the item is a date/time item and another item is a constant. This is done
to get a correct result of comparisons like date_time_function() = string_constant.


mysql-test/r/cast.result:
  Fixed wrong test case result after bug fix#16377.
sql/item_timefunc.h:
  Fixed bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
  The result_as_longlong() function is set to return TRUE for these classes:
  Item_date, Item_date_func, Item_func_curtime, Item_func_sec_to_time,
  Item_date_typecast, Item_time_typecast, Item_datetime_typecast,
  Item_func_makedate.
sql/item_timefunc.cc:
  Fixed bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.Correct val_int() methods are implemented for classes Item_date_typecast, 
  Item_func_makedate, Item_time_typecast, Item_datetime_typecast.
sql/item_cmpfunc.h:
  Fixed bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
  Arg_comparator::set_compare_func() and Arg_comparator::set_cmp_func()
  functions are changed to substitute result type of an item with the INT_RESULT
  if the item is a date/time item and another item is a constant.
sql/field.cc:
  Fixed bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
  Field::set_warning(), Field::set_datetime_warning() now use current_thd to get thd if table isn't set.
sql/item_cmpfunc.cc:
  Fixed bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
  The agg_cmp_type() function now accepts THD as one of parameters. 
  In addition, it now checks if a date/time field/function is present in the
  list. If so, it tries to coerce all constants to INT to make date/time
  comparison return correct result. The field for the constant coercion is
  taken from the Item_field or constructed from the Item_func. In latter case
  the constructed field will be freed after conversion of all constant items.
  Otherwise the result is same as before - aggregated with help of the
  item_cmp_type() function.
sql/item.h:
  The new function result_as_longlong() is added to the Item class. 
  It indicates that the item is a date/time item and result of it can be
  compared as int. Such items are date/time fields/functions.
mysql-test/t/func_time.test:
  Added test case fot bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
mysql-test/r/func_time.result:
  Added test case fot bug#16377: result of DATE/TIME functions were compared as strings which
  can lead to a wrong result.
parent a9824f26

mysql-test/r/cast.result

+1 −1
Original line number Diff line number Diff line
@@ -192,7 +192,7 @@ cast("2001-1-1" as datetime) = "2001-01-01 00:00:00" 
1

select cast("1:2:3" as TIME) = "1:02:03";

cast("1:2:3" as TIME) = "1:02:03"

0

1

select cast(NULL as DATE);

cast(NULL as DATE)

NULL

mysql-test/r/func_time.result

+41 −0
Original line number Diff line number Diff line
@@ -630,3 +630,44 @@ select monthname(str_to_date(null, '%m')), monthname(str_to_date(null, '%m')), 
monthname(str_to_date(1, '%m')), monthname(str_to_date(0, '%m'));

monthname(str_to_date(null, '%m'))	monthname(str_to_date(null, '%m'))	monthname(str_to_date(1, '%m'))	monthname(str_to_date(0, '%m'))

NULL	NULL	January	NULL

create table t1(f1 date, f2 time, f3 datetime);

insert into t1 values ("2006-01-01", "12:01:01", "2006-01-01 12:01:01");

insert into t1 values ("2006-01-02", "12:01:02", "2006-01-02 12:01:02");

select f1 from t1 where f1 between "2006-1-1" and 20060101;

f1

2006-01-01

select f1 from t1 where f1 between "2006-1-1" and "2006.1.1";

f1

2006-01-01

select f1 from t1 where date(f1) between "2006-1-1" and "2006.1.1";

f1

2006-01-01

select f2 from t1 where f2 between "12:1:2" and "12:2:2";

f2

12:01:02

select f2 from t1 where time(f2) between "12:1:2" and "12:2:2";

f2

12:01:02

select f3 from t1 where f3 between "2006-1-1 12:1:1" and "2006-1-1 12:1:2";

f3

2006-01-01 12:01:01

select f3 from t1 where timestamp(f3) between "2006-1-1 12:1:1" and "2006-1-1 12:1:2";

f3

2006-01-01 12:01:01

select f1 from t1 where "2006-1-1" between f1 and f3;

f1

2006-01-01

select f1 from t1 where "2006-1-1" between date(f1) and date(f3);

f1

2006-01-01

select f1 from t1 where "2006-1-1" between f1 and 'zzz';

f1

Warnings:

Warning	1292	Truncated incorrect date value: 'zzz'

select f1 from t1 where makedate(2006,1) between date(f1) and date(f3);

f1

2006-01-01

select f1 from t1 where makedate(2006,2) between date(f1) and date(f3);

f1

2006-01-02

drop table t1;

mysql-test/t/func_time.test

+20 −0
Original line number Diff line number Diff line
@@ -322,4 +322,24 @@ select last_day('2005-01-00'); 
select monthname(str_to_date(null, '%m')), monthname(str_to_date(null, '%m')),

       monthname(str_to_date(1, '%m')), monthname(str_to_date(0, '%m'));



#

# Bug#16377 result of DATE/TIME functions were compared as strings which

#           can lead to a wrong result.

#

create table t1(f1 date, f2 time, f3 datetime);

insert into t1 values ("2006-01-01", "12:01:01", "2006-01-01 12:01:01");

insert into t1 values ("2006-01-02", "12:01:02", "2006-01-02 12:01:02");

select f1 from t1 where f1 between "2006-1-1" and 20060101;

select f1 from t1 where f1 between "2006-1-1" and "2006.1.1";

select f1 from t1 where date(f1) between "2006-1-1" and "2006.1.1";

select f2 from t1 where f2 between "12:1:2" and "12:2:2";

select f2 from t1 where time(f2) between "12:1:2" and "12:2:2";

select f3 from t1 where f3 between "2006-1-1 12:1:1" and "2006-1-1 12:1:2";

select f3 from t1 where timestamp(f3) between "2006-1-1 12:1:1" and "2006-1-1 12:1:2";

select f1 from t1 where "2006-1-1" between f1 and f3;

select f1 from t1 where "2006-1-1" between date(f1) and date(f3);

select f1 from t1 where "2006-1-1" between f1 and 'zzz';

select f1 from t1 where makedate(2006,1) between date(f1) and date(f3);

select f1 from t1 where makedate(2006,2) between date(f1) and date(f3);

drop table t1;

# End of 4.1 tests

sql/field.cc

+11 −5
Original line number Diff line number Diff line
@@ -6841,7 +6841,11 @@ create_field::create_field(Field *old_field,Field *orig_field) 
bool 

Field::set_warning(const uint level, const uint code, int cuted_increment)

{

  THD *thd= table->in_use;

  /*

    If this field was created only for type conversion purposes it

    will have table == NULL.

  */

  THD *thd= table ? table->in_use : current_thd;

  if (thd->count_cuted_fields)

  {

    thd->cuted_fields+= cuted_increment;
@@ -6876,7 +6880,8 @@ Field::set_datetime_warning(const uint level, const uint code, 
                            timestamp_type ts_type, int cuted_increment)

{

  if (set_warning(level, code, cuted_increment))

    make_truncated_value_warning(table->in_use, str, str_length, ts_type);

    make_truncated_value_warning(table ? table->in_use : current_thd,

                                 str, str_length, ts_type);

}
@@ -6905,8 +6910,8 @@ Field::set_datetime_warning(const uint level, const uint code, 
  {

    char str_nr[22];

    char *str_end= longlong10_to_str(nr, str_nr, -10);

    make_truncated_value_warning(table->in_use, str_nr, str_end - str_nr, 

                                 ts_type);

    make_truncated_value_warning(table ? table->in_use : current_thd,

                                 str_nr, str_end - str_nr, ts_type);

  }

}
@@ -6935,7 +6940,8 @@ Field::set_datetime_warning(const uint level, const uint code, 
    /* DBL_DIG is enough to print '-[digits].E+###' */

    char str_nr[DBL_DIG + 8];

    uint str_len= my_sprintf(str_nr, (str_nr, "%g", nr));

    make_truncated_value_warning(table->in_use, str_nr, str_len, ts_type);

    make_truncated_value_warning(table ? table->in_use : current_thd,

                                 str_nr, str_len, ts_type);

  }

}

sql/item.h

+16 −0
Original line number Diff line number Diff line
@@ -327,6 +327,14 @@ class Item { 
    cleanup();

    delete this;

  }

  /*

    result_as_longlong() must return TRUE for Items representing DATE/TIME

    functions and DATE/TIME table fields.

    Those Items have result_type()==STRING_RESULT (and not INT_RESULT), but

    their values should be compared as integers (because the integer

    representation is more precise than the string one).

  */

  virtual bool result_as_longlong() { return FALSE; }

};
@@ -450,6 +458,10 @@ class Item_field :public Item_ident 
  Item *get_tmp_table_item(THD *thd);

  void cleanup();

  inline uint32 max_disp_length() { return field->max_length(); }

  bool result_as_longlong()

  {

    return field->can_be_compared_as_longlong();

  }

  friend class Item_default_value;

  friend class Item_insert_value;

  friend class st_select_lex_unit;
@@ -973,6 +985,10 @@ class Item_ref :public Item_ident 
  }

  Item *real_item() { return *ref; }

  void print(String *str);

  bool result_as_longlong()

  {

    return (*ref)->result_as_longlong();

  }

};