reset() split in 2 function clear() & add()

aggregate function reinitialization (if no rows was found) made with help of clear()
(fixed BUG#860)

mysql-test/r/subselect.result

@@ -1352,3 +1352,12 @@ ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_
 select * from t1 where s1 > any (select max(s2) from t1);
 ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '>'
 drop table t1;
+create table t1(toid int,rd int);
+create table t2(userid int,pmnew int,pmtotal int);
+insert into t2 values(1,0,0),(2,0,0);
+insert into t1 values(1,0),(1,0),(1,0),(1,12),(1,15),(1,123),(1,12312),(1,12312),(1,123),(2,0),(2,0),(2,1),(2,2);
+select userid,pmtotal,pmnew, (select count(rd) from t1 where toid=t2.userid) calc_total, (select count(rd) from t1 where rd=0 and toid=t2.userid) calc_new from t2 where userid in (select distinct toid from t1);
+userid	pmtotal	pmnew	calc_total	calc_new
+1	0	0	9	3
+2	0	0	4	2
+drop table t1, t2;

mysql-test/t/subselect.test

@@ -912,3 +912,13 @@ select * from t1 where s1 > (select max(s2) from t1);
 -- error 1266
 select * from t1 where s1 > any (select max(s2) from t1);
 drop table t1;
+
+#
+# aggregate functions reinitialization
+#
+create table t1(toid int,rd int);
+create table t2(userid int,pmnew int,pmtotal int);
+insert into t2 values(1,0,0),(2,0,0);
+insert into t1 values(1,0),(1,0),(1,0),(1,12),(1,15),(1,123),(1,12312),(1,12312),(1,123),(2,0),(2,0),(2,1),(2,2);
+select userid,pmtotal,pmnew, (select count(rd) from t1 where toid=t2.userid) calc_total, (select count(rd) from t1 where rd=0 and toid=t2.userid) calc_new from t2 where userid in (select distinct toid from t1);
+drop table t1, t2;

sql/item_sum.cc

@@ -223,10 +223,9 @@ Item *Item_sum_sum::copy_or_same(THD* thd)
 }
 
 
-bool Item_sum_sum::reset()
+void Item_sum_sum::clear()
 {
   null_value=1; sum=0.0;
-  return Item_sum_sum::add();
 }
 
 
@@ -251,10 +250,9 @@ Item *Item_sum_count::copy_or_same(THD* thd)
 }
 
 
-bool Item_sum_count::reset()
+void Item_sum_count::clear()
 {
-  count=0;
+  count= 0;
-  return add();
 }
 
 
@@ -286,10 +284,9 @@ Item *Item_sum_avg::copy_or_same(THD* thd)
 }
 
 
-bool Item_sum_avg::reset()
+void Item_sum_avg::clear()
 {
   sum=0.0; count=0;
-  return Item_sum_avg::add();
 }
 
 
@@ -342,11 +339,10 @@ Item *Item_sum_variance::copy_or_same(THD* thd)
 }
 
 
-bool Item_sum_variance::reset()
+void Item_sum_variance::clear()
 {
   sum=sum_sqr=0.0; 
   count=0; 
-  return Item_sum_variance::add();
 }
 
 bool Item_sum_variance::add()
@@ -592,10 +588,9 @@ longlong Item_sum_bit::val_int()
 }
 
 
-bool Item_sum_bit::reset()
+void Item_sum_bit::clear()
 {
-  bits=reset_bits;
+  bits= reset_bits;
-  return add();
 }
 
 Item *Item_sum_or::copy_or_same(THD* thd)
@@ -1280,7 +1275,7 @@ Item *Item_sum_count_distinct::copy_or_same(THD* thd)
 }
 
 
-bool Item_sum_count_distinct::reset()
+void Item_sum_count_distinct::clear()
 {
   if (use_tree)
     reset_tree(tree);
@@ -1290,7 +1285,6 @@ bool Item_sum_count_distinct::reset()
     table->file->delete_all_rows();
     table->file->extra(HA_EXTRA_WRITE_CACHE);
   }
-  return add();
 }
 
 bool Item_sum_count_distinct::add()
@@ -1353,11 +1347,11 @@ longlong Item_sum_count_distinct::val_int()
 
 #ifdef HAVE_DLOPEN
 
-bool Item_udf_sum::clear()
+void Item_udf_sum::clear()
 {
-  DBUG_ENTER("Item_udf_sum::reset");
+  DBUG_ENTER("Item_udf_sum::clear");
   udf.clear();
-  DBUG_RETURN(0);
+  DBUG_VOID_RETURN;
 }
 
 bool Item_udf_sum::add()
@@ -1685,7 +1679,7 @@ Item *Item_func_group_concat::copy_or_same(THD* thd)
 }
 
 
-bool Item_func_group_concat::reset()
+void Item_func_group_concat::clear()
 {
   result.length(0);
   result.copy();
@@ -1699,7 +1693,6 @@ bool Item_func_group_concat::reset()
   }
   if (tree_mode)
     reset_tree(tree);
-  return add();
 }
 
 

sql/item_sum.h

@@ -62,7 +62,8 @@ public:
 
   enum Type type() const { return SUM_FUNC_ITEM; }
   virtual enum Sumfunctype sum_func () const=0;
-  virtual bool reset()=0;
+  inline bool reset() { clear(); return add(); };
+  virtual void clear()= 0;
   virtual bool add()=0;
   virtual void reset_field()=0;
   virtual void update_field(int offset)=0;
@@ -124,7 +125,7 @@ class Item_sum_sum :public Item_sum_num
   Item_sum_sum(THD *thd, Item_sum_sum &item) 
     :Item_sum_num(thd, item), sum(item.sum) {}
   enum Sumfunctype sum_func () const {return SUM_FUNC;}
-  bool reset();
+  void clear();
   bool add();
   double val();
   void reset_field();
@@ -151,7 +152,7 @@ class Item_sum_count :public Item_sum_int
   table_map used_tables() const { return used_table_cache; }
   bool const_item() const { return !used_table_cache; }
   enum Sumfunctype sum_func () const { return COUNT_FUNC; }
-  bool reset();
+  void clear();
   void no_rows_in_result() { count=0; }
   bool add();
   void make_const(longlong count_arg) { count=count_arg; used_table_cache=0; }
@@ -225,7 +226,7 @@ class Item_sum_count_distinct :public Item_sum_int
 
   table_map used_tables() const { return used_table_cache; }
   enum Sumfunctype sum_func () const { return COUNT_DISTINCT_FUNC; }
-  bool reset();
+  void clear();
   bool add();
   longlong val_int();
   void reset_field() { return ;}		// Never called
@@ -269,7 +270,7 @@ class Item_sum_avg :public Item_sum_num
   Item_sum_avg(THD *thd, Item_sum_avg &item)
     :Item_sum_num(thd, item), sum(item.sum), count(item.count) {}
   enum Sumfunctype sum_func () const {return AVG_FUNC;}
-  bool reset();
+  void clear();
   bool add();
   double val();
   void reset_field();
@@ -322,7 +323,7 @@ class Item_sum_variance : public Item_sum_num
     Item_sum_num(thd, item), sum(item.sum), sum_sqr(item.sum_sqr),
     count(item.count) {}
   enum Sumfunctype sum_func () const { return VARIANCE_FUNC; }
-  bool reset();
+  void clear();
   bool add();
   double val();
   void reset_field();
@@ -391,13 +392,12 @@ class Item_sum_hybrid :public Item_sum
   table_map used_tables() const { return used_table_cache; }
   bool const_item() const { return !used_table_cache; }
 
-  bool reset()
+  void clear()
   {
     sum=0.0;
     sum_int=0;
     value.length(0);
     null_value=1;
-    return add();
   }
   double val();
   longlong val_int();
@@ -451,7 +451,7 @@ class Item_sum_bit :public Item_sum_int
   Item_sum_bit(THD *thd, Item_sum_bit &item):
     Item_sum_int(thd, item), reset_bits(item.reset_bits), bits(item.bits) {}
   enum Sumfunctype sum_func () const {return SUM_BIT_FUNC;}
-  bool reset();
+  void clear();
   longlong val_int();
   void reset_field();
   void fix_length_and_dec()
@@ -509,8 +509,7 @@ public:
   enum Sumfunctype sum_func () const { return UDF_SUM_FUNC; }
   virtual bool have_field_update(void) const { return 0; }
 
-  bool reset() { return 0; }			/* TO BE FIXED */
+  void clear();
-  bool clear();
   bool add();
   void reset_field() {};
   void update_field(int offset_arg) {};
@@ -592,7 +591,7 @@ class Item_sum_udf_float :public Item_sum_num
   ~Item_sum_udf_float() {}
   enum Sumfunctype sum_func () const { return UDF_SUM_FUNC; }
   double val() { return 0.0; }
-  bool reset() { return 0; }
+  bool clear() {}
   bool add() { return 0; }  
   void update_field(int offset) {}
 };
@@ -609,7 +608,7 @@ public:
   enum Sumfunctype sum_func () const { return UDF_SUM_FUNC; }
   longlong val_int() { return 0; }
   double val() { return 0; }
-  bool reset() { return 0; }
+  void clear() {}
   bool add() { return 0; }  
   void update_field(int offset) {}
 };
@@ -629,7 +628,7 @@ public:
   enum Item_result result_type () const { return STRING_RESULT; }
   void fix_length_and_dec() { maybe_null=1; max_length=0; }
   enum Sumfunctype sum_func () const { return UDF_SUM_FUNC; }
-  bool reset() { return 0; }
+  void clear() {}
   bool add() { return 0; }  
   void update_field(int offset) {}
 };
@@ -715,7 +714,7 @@ class Item_func_group_concat : public Item_sum
   const char *func_name() const { return "group_concat"; }
   enum Type type() const { return SUM_FUNC_ITEM; }  
   virtual Item_result result_type () const { return STRING_RESULT; }
-  bool reset();
+  void clear();
   bool add();
   void reset_field();
   bool fix_fields(THD *, TABLE_LIST *, Item **);

sql/item_uniq.h

@@ -41,7 +41,7 @@ public:
     :Item_sum_num(thd, item) {}
   double val() { return 0.0; }  
   enum Sumfunctype sum_func () const {return UNIQUE_USERS_FUNC;}
-  bool reset() { return 0;}
+  void clear() {}
   bool add() { return 0; }
   void reset_field() {}
   void update_field(int offset) {}

sql/sql_select.cc

@@ -1003,12 +1003,6 @@ JOIN::reinit()
   
   /* Reset of sum functions */
   first_record= 0;
-  if (sum_funcs)
-  {
-    Item_sum *func, **func_ptr= sum_funcs;
-    while ((func= *(func_ptr++)))
-      func->null_value= 1;
-  }
 
   if (exec_tmp_table1)
   {
@@ -5979,8 +5973,7 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
 	  if (!join->first_record)
 	  {
 	    /* No matching rows for group function */
-	    clear_tables(join);
+	    join->clear();
-	    copy_fields(&join->tmp_table_param);
 	  }
 	  if (join->having && join->having->val_int() == 0)
 	    error= -1;				// Didn't satisfy having
@@ -6246,8 +6239,7 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
 	if (!join->first_record)
 	{
 	  /* No matching rows for group function */
-	  clear_tables(join);
+	  join->clear();
-	  copy_fields(&join->tmp_table_param);
 	}
 	copy_sum_funcs(join->sum_funcs);
 	if (!join->having || join->having->val_int())
@@ -8542,6 +8534,26 @@ int JOIN::rollup_send_data(uint idx)
   return 0;
 }
 
+/*
+  clear results if there are not rows found for group
+  (end_send_group/end_write_group)
+
+  SYNOPSYS
+     JOIN::clear()
+*/
+
+void JOIN::clear()
+{
+  clear_tables(this);
+  copy_fields(&tmp_table_param);
+
+  if (sum_funcs)
+  {
+    Item_sum *func, **func_ptr= sum_funcs;
+    while ((func= *(func_ptr++)))
+      func->clear();
+  }
+}
 
 /****************************************************************************
   EXPLAIN handling

sql/sql_select.h

@@ -279,6 +279,7 @@ class JOIN :public Sql_alloc
 			  Item_sum ***func);
   int rollup_send_data(uint idx);
   bool test_in_subselect(Item **where);
+  void clear();
 };