Commit fbf6507c authored by kroki/tomash@moonlight.intranet's avatar kroki/tomash@moonlight.intranet
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BUG#21354: (COUNT(*) = 1) not working in SELECT inside prepared 

           statement.

The problem was that during statement re-execution if the result was
empty the old result could be returned for group functions.

The solution is to implement proper cleanup() method in group
functions.
parent a55d18e7

mysql-test/r/ps.result

+97 −0
Original line number Diff line number Diff line
@@ -889,3 +889,100 @@ create temporary table if not exists t1 (a1 int); 
execute stmt;

drop temporary table t1;

deallocate prepare stmt;

DROP TABLE IF EXISTS t1;

CREATE TABLE t1 (i INT, INDEX(i));

INSERT INTO t1 VALUES (1);

PREPARE stmt FROM "SELECT (COUNT(i) = 1), COUNT(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(COUNT(i) = 1)	COUNT(i)

0	0

SET @a = 1;

EXECUTE stmt USING @a;

(COUNT(i) = 1)	COUNT(i)

1	1

SET @a = 0;

EXECUTE stmt USING @a;

(COUNT(i) = 1)	COUNT(i)

0	0

PREPARE stmt FROM "SELECT (AVG(i) = 1), AVG(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(AVG(i) = 1)	AVG(i)

NULL	NULL

SET @a = 1;

EXECUTE stmt USING @a;

(AVG(i) = 1)	AVG(i)

1	1.0000

SET @a = 0;

EXECUTE stmt USING @a;

(AVG(i) = 1)	AVG(i)

NULL	NULL

PREPARE stmt FROM "SELECT (VARIANCE(i) = 1), VARIANCE(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(VARIANCE(i) = 1)	VARIANCE(i)

NULL	NULL

SET @a = 1;

EXECUTE stmt USING @a;

(VARIANCE(i) = 1)	VARIANCE(i)

0	0.0000

SET @a = 0;

EXECUTE stmt USING @a;

(VARIANCE(i) = 1)	VARIANCE(i)

NULL	NULL

PREPARE stmt FROM "SELECT (STDDEV(i) = 1), STDDEV(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(STDDEV(i) = 1)	STDDEV(i)

NULL	NULL

SET @a = 1;

EXECUTE stmt USING @a;

(STDDEV(i) = 1)	STDDEV(i)

0	0.0000

SET @a = 0;

EXECUTE stmt USING @a;

(STDDEV(i) = 1)	STDDEV(i)

NULL	NULL

PREPARE stmt FROM "SELECT (BIT_OR(i) = 1), BIT_OR(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_OR(i) = 1)	BIT_OR(i)

0	0

SET @a = 1;

EXECUTE stmt USING @a;

(BIT_OR(i) = 1)	BIT_OR(i)

1	1

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_OR(i) = 1)	BIT_OR(i)

0	0

PREPARE stmt FROM "SELECT (BIT_AND(i) = 1), BIT_AND(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_AND(i) = 1)	BIT_AND(i)

0	18446744073709551615

SET @a = 1;

EXECUTE stmt USING @a;

(BIT_AND(i) = 1)	BIT_AND(i)

1	1

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_AND(i) = 1)	BIT_AND(i)

0	18446744073709551615

PREPARE stmt FROM "SELECT (BIT_XOR(i) = 1), BIT_XOR(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_XOR(i) = 1)	BIT_XOR(i)

0	0

SET @a = 1;

EXECUTE stmt USING @a;

(BIT_XOR(i) = 1)	BIT_XOR(i)

1	1

SET @a = 0;

EXECUTE stmt USING @a;

(BIT_XOR(i) = 1)	BIT_XOR(i)

0	0

DEALLOCATE PREPARE stmt;

DROP TABLE t1;

End of 4.1 tests.

mysql-test/t/func_gconcat.test

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ select ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'withou 
select distinct ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'with distinct: cutoff at length of shortname' from t1;

drop table t1;



# check zero rows

# check zero rows (bug#836)

create table t1(id int);

create table t2(id int);

insert into t1 values(0),(1);

mysql-test/t/ps.test

+73 −1
Original line number Diff line number Diff line
@@ -951,4 +951,76 @@ execute stmt; 
drop temporary table t1;

deallocate prepare stmt;



# End of 4.1 tests
 


#

# BUG#21354: (COUNT(*) = 1) not working in SELECT inside prepared

# statement 

#

--disable_warnings

DROP TABLE IF EXISTS t1;

--enable_warnings



CREATE TABLE t1 (i INT, INDEX(i));

INSERT INTO t1 VALUES (1);



PREPARE stmt FROM "SELECT (COUNT(i) = 1), COUNT(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (AVG(i) = 1), AVG(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (VARIANCE(i) = 1), VARIANCE(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (STDDEV(i) = 1), STDDEV(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (BIT_OR(i) = 1), BIT_OR(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (BIT_AND(i) = 1), BIT_AND(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



PREPARE stmt FROM "SELECT (BIT_XOR(i) = 1), BIT_XOR(i) FROM t1 WHERE i = ?";

SET @a = 0;

EXECUTE stmt USING @a;

SET @a = 1;

EXECUTE stmt USING @a;

SET @a = 0;

EXECUTE stmt USING @a;



DEALLOCATE PREPARE stmt;

DROP TABLE t1;





--echo End of 4.1 tests.

sql/item_sum.cc

+1 −0
Original line number Diff line number Diff line
@@ -312,6 +312,7 @@ longlong Item_sum_count::val_int() 
void Item_sum_count::cleanup()

{

  DBUG_ENTER("Item_sum_count::cleanup");

  clear();

  Item_sum_int::cleanup();

  used_table_cache= ~(table_map) 0;

  DBUG_VOID_RETURN;

sql/item_sum.h

+47 −1
Original line number Diff line number Diff line
@@ -58,9 +58,30 @@ class Item_sum :public Item_result_field 
  Item_sum(THD *thd, Item_sum *item);

  enum Type type() const { return SUM_FUNC_ITEM; }

  virtual enum Sumfunctype sum_func () const=0;



  /*

    This method is similar to add(), but it is called when the current

    aggregation group changes. Thus it performs a combination of

    clear() and add().

  */

  inline bool reset() { clear(); return add(); };



  /*

    Prepare this item for evaluation of an aggregate value. This is

    called by reset() when a group changes, or, for correlated

    subqueries, between subquery executions.  E.g. for COUNT(), this

    method should set count= 0;

  */

  virtual void clear()= 0;



  /*

    This method is called for the next row in the same group. Its

    purpose is to aggregate the new value to the previous values in

    the group (i.e. since clear() was called last time). For example,

    for COUNT(), do count++.

  */

  virtual bool add()=0;



  /*

    Called when new group is started and results are being saved in

    a temporary table. Similar to reset(), but must also store value in
@@ -86,7 +107,17 @@ class Item_sum :public Item_result_field 
  void make_field(Send_field *field);

  void print(String *str);

  void fix_num_length_and_dec();

  void no_rows_in_result() { reset(); }



  /*

    This function is called by the execution engine to assign 'NO ROWS

    FOUND' value to an aggregate item, when the underlying result set

    has no rows. Such value, in a general case, may be different from

    the default value of the item after 'clear()': e.g. a numeric item

    may be initialized to 0 by clear() and to NULL by

    no_rows_in_result().

  */

  void no_rows_in_result() { clear(); }



  virtual bool setup(THD *thd) {return 0;}

  virtual void make_unique() {}

  Item *get_tmp_table_item(THD *thd);
@@ -304,6 +335,11 @@ class Item_sum_avg :public Item_sum_num 
  void no_rows_in_result() {}

  const char *func_name() const { return "avg"; }

  Item *copy_or_same(THD* thd);

  void cleanup()

  {

    clear();

    Item_sum_num::cleanup();

  }

};



class Item_sum_variance;
@@ -361,6 +397,11 @@ class Item_sum_variance : public Item_sum_num 
  void no_rows_in_result() {}

  const char *func_name() const { return "variance"; }

  Item *copy_or_same(THD* thd);

  void cleanup()

  {

    clear();

    Item_sum_num::cleanup();

  }

};



class Item_sum_std;
@@ -485,6 +526,11 @@ class Item_sum_bit :public Item_sum_int 
  void update_field();

  void fix_length_and_dec()

  { decimals=0; max_length=21; unsigned_flag=1; maybe_null=null_value=0; }

  void cleanup()

  {

    clear();

    Item_sum_int::cleanup();

  }

};