new subselect tests

LIMIT fixed
AVG & STD with subselect fixed
join_free fixed to be depended queries compatible
sort_default removed from SELECT_LEX


mysql-test/r/subselect.result:
  new subselect tests
mysql-test/t/subselect.test:
  new subselect tests
sql/item.cc:
  marking as depended _ALL_ subselects under select from wich depend
sql/item_subselect.cc:
  limit fixed
  TODO added
sql/sql_class.cc:
  AVG & STD function with subselects fixed
sql/sql_lex.h:
  sort_default removed
sql/sql_parse.cc:
  limit fixed
sql/sql_select.cc:
  fixed to be subselect compatible
sql/sql_yacc.yy:
  sort_default removed

mysql-test/r/subselect.result

+select (select 2);
+(select 2)
+2
 drop table if exists t1,t2,t3,t4;
 create table t1 (a int);
 create table t2 (a int, b int);
@@ -26,18 +29,42 @@ select * from t2 where t2.a=(select a from t1);
 a	b
 2	7
 insert into t3 values (6),(7),(3);
-select * from t2 where t2.b=(select a from t3 order by 1 limit 1);
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1);
 a	b
 1	7
 2	7
-select * from t2 where t2.b=(select a from t3 order by 1 limit 1) 
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
 union (select * from t4 order by a limit 2) limit 3;
 a	b
 1	7
 2	7
 3	8
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
+union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
+a	b
+1	7
+2	7
+3	8
+4	8
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 (select a from t3 where a<t2.a*4 order by 1 desc limit 1)	a
 3	1
 7	2
+select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
+(select * from t2 where a>1) as tt;
+(select t3.a from t3 where a<8 order by 1 desc limit 1)	a
+7	2
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
+a
+2
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1);
+a
+2
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1);
+a
+select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
+b	(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)
+8	7.5000
+8	6.0000
+9	5.5000
 drop table t1,t2,t3,t4;

mysql-test/t/subselect.test

 
-#select (select 2);
+select (select 2);
 drop table if exists t1,t2,t3,t4;
 create table t1 (a int);
 create table t2 (a int, b int);
@@ -17,7 +17,13 @@ insert into t3 values (6),(7),(3);
 select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1);
 select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
 union (select * from t4 order by a limit 2) limit 3;
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
+union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
 (select * from t2 where a>1) as tt;
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1);
+select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1);
+select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
 drop table t1,t2,t3,t4;

sql/item.cc

@@ -330,23 +330,32 @@ bool Item_field::fix_fields(THD *thd,TABLE_LIST *tables)
 	mention of table name, but if we join tables in one list it will
 	cause error ER_NON_UNIQ_ERROR in find_field_in_tables.
       */
+      SELECT_LEX *last;
       for (SELECT_LEX *sl= thd->lex.select->outer_select();
 	   sl && !tmp;
 	   sl= sl->outer_select())
 	tmp=find_field_in_tables(thd, this,
-				 (TABLE_LIST*)sl->table_list.first);
+				 (TABLE_LIST*)(last= sl)->table_list.first);
       if (!tmp)
 	return 1;
       else
-	if( !thd->lex.select->depended )
-	{
-	  thd->lex.select->depended= 1; //Select is depended of outer select(s)
-	  //Tables will be reopened many times
-	  for (TABLE_LIST *tbl= (TABLE_LIST*)thd->lex.select->table_list.first;
-	       tbl;
-	       tbl= tbl->next)
-	    tbl->shared= 1;
-	}
+	/*
+	  Mark all selects from resolved to 1 before select where was 
+	  found table as depended (of select where was found table)
+	*/
+	for (SELECT_LEX *s= thd->lex.select;
+	     s &&s != last;
+	     s= s->outer_select())
+	  if( !s->depended )
+	  {
+	    s->depended= 1; //Select is depended of outer select
+	    //Tables will be reopened many times
+	    for (TABLE_LIST *tbl= 
+		   (TABLE_LIST*)s->table_list.first;
+		 tbl;
+		 tbl= tbl->next)
+	      tbl->shared= 1;
+	  }
     }
     set_field(tmp);
   }

sql/item_subselect.cc

@@ -23,6 +23,7 @@ SUBSELECT TODO:
    - remove double 'having' & 'having_list' from JOIN
      (sql_select.h/sql_select.cc)
 
+   - subselect in HAVING clause
    - add subselect union select (sql_union.cc)
    
 */
@@ -43,7 +44,7 @@ Item_subselect::Item_subselect(THD *thd, st_select_lex *select_lex):
   SELECT_LEX_UNIT *unit= select_lex->master_unit();
   unit->offset_limit_cnt= unit->global_parameters->offset_limit;
   unit->select_limit_cnt= unit->global_parameters->select_limit+
-    select_lex->offset_limit;
+    unit->global_parameters ->offset_limit;
   if (unit->select_limit_cnt < unit->global_parameters->select_limit)
     unit->select_limit_cnt= HA_POS_ERROR;		// no limit
   if (unit->select_limit_cnt == HA_POS_ERROR)
@@ -148,9 +149,6 @@ int Item_subselect::exec()
     join->thd->lex.select= select_lex;
     join->exec();
     join->thd->lex.select= save_select;
-    //if (!executed)
-      //No rows returned => value is null (returned as inited)
-    //  executed= 1;
     return join->error;
   }
   return 0;

sql/sql_class.cc

@@ -790,11 +790,17 @@ bool select_subselect::send_data(List<Item> &items)
     DBUG_RETURN(1);
   }
   if (unit->offset_limit_cnt)
-  {						// using limit offset,count
+  {				          // Using limit offset,count
     unit->offset_limit_cnt--;
     DBUG_RETURN(0);
   }
-  Item *val_item= (Item *)item->select_lex->item_list.head();
+  List_iterator_fast<Item> li(items);
+  Item *val_item= li++;                   // Only one (single value subselect)
+  /*
+    Following val() call have to be first, because function AVG() & STD()
+    calculate value on it & determinate "is it NULL?".
+  */
+  item->real_value= val_item->val();
   if ((item->null_value= val_item->is_null()))
   {
     item->assign_null();
@@ -804,7 +810,6 @@ bool select_subselect::send_data(List<Item> &items)
     item->binary= val_item->binary;
     val_item->val_str(&item->str_value);
     item->int_value= val_item->val_int();
-    item->real_value= val_item->val();
     item->res_type= val_item->result_type();
   }
   item->executed= 1;

sql/sql_lex.h

@@ -194,7 +194,6 @@ class st_select_lex_node {
 public:
   ulong options;
   enum sub_select_type linkage;
-  //uint sort_default;
   SQL_LIST order_list;                /* ORDER clause */
   ha_rows select_limit, offset_limit; /* LIMIT clause parameters */
   void init_query();

sql/sql_parse.cc

@@ -2690,12 +2690,12 @@ mysql_init_query(THD *thd)
 void
 mysql_init_select(LEX *lex)
 {
-  SELECT_LEX *select_lex = lex->select;
+  SELECT_LEX *select_lex= lex->select;
   select_lex->init_select();
-  select_lex->select_limit=lex->thd->default_select_limit;
-  select_lex->offset_limit=0;
-  lex->exchange = 0;
-  lex->proc_list.first=0;
+  select_lex->master_unit()->select_limit= select_lex->select_limit= 
+    lex->thd->default_select_limit;
+  lex->exchange= 0;
+  lex->proc_list.first= 0;
 }
 
 bool

sql/sql_select.cc

@@ -607,9 +607,10 @@ JOIN::reinit()
     unit->select_limit_cnt= HA_POS_ERROR;		// no limit
   if (unit->select_limit_cnt == HA_POS_ERROR)
     select_lex->options&= ~OPTION_FOUND_ROWS;
-
+  
   if (setup_tables(tables_list))
     DBUG_RETURN(1);
+
   DBUG_RETURN(0);
 }
 
@@ -2830,7 +2831,9 @@ join_free(JOIN *join)
       }
       end_read_record(&tab->read_record);
     }
-    join->table=0;
+    //TODO: is enough join_free at the end of mysql_select?
+    if (!join->select_lex->depended)
+      join->table=0;
   }
   // We are not using tables anymore
   // Unlock all tables. We may be in an INSERT .... SELECT statement.

sql/sql_yacc.yy

@@ -2325,7 +2325,6 @@ order_clause:
 	  LEX *lex=Lex;
 	  if (lex->sql_command == SQLCOM_MULTI_UPDATE)
 	    YYABORT;
-	  /*lex->select->sort_default=1;*/
 	} order_list
 
 order_list: