Commit 40320e8c authored by unknown's avatar unknown
Browse files

Merge weblab.(none):/home/marcsql/TREE/mysql-5.0-21904 

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-21904-merge


sql/item_subselect.cc:
  Auto merged
sql/item_subselect.h:
  Auto merged
sql/sql_yacc.yy:
  Auto merged
parents 2f6812be a1e20e04

sql/item_subselect.cc

+30 −0
Original line number Diff line number Diff line
@@ -51,6 +51,10 @@ Item_subselect::Item_subselect(): 
void Item_subselect::init(st_select_lex *select_lex,

			  select_subselect *result)

{

  /*

    Please see Item_singlerow_subselect::invalidate_and_restore_select_lex(),

    which depends on alterations to the parse tree implemented here.

  */



  DBUG_ENTER("Item_subselect::init");

  DBUG_PRINT("enter", ("select_lex: 0x%lx", (long) select_lex));
@@ -91,6 +95,12 @@ void Item_subselect::init(st_select_lex *select_lex, 
  DBUG_VOID_RETURN;

}



st_select_lex *

Item_subselect::get_select_lex()

{

  return unit->first_select();

}



void Item_subselect::cleanup()

{

  DBUG_ENTER("Item_subselect::cleanup");
@@ -307,6 +317,26 @@ Item_singlerow_subselect::Item_singlerow_subselect(st_select_lex *select_lex) 
  DBUG_VOID_RETURN;

}



st_select_lex *

Item_singlerow_subselect::invalidate_and_restore_select_lex()

{

  DBUG_ENTER("Item_singlerow_subselect::invalidate_and_restore_select_lex");

  st_select_lex *result= get_select_lex();



  DBUG_ASSERT(result);



  /*

    This code restore the parse tree in it's state before the execution of

    Item_singlerow_subselect::Item_singlerow_subselect(),

    and in particular decouples this object from the SELECT_LEX,

    so that the SELECT_LEX can be used with a different flavor

    or Item_subselect instead, as part of query rewriting.

  */

  unit->item= NULL;



  DBUG_RETURN(result);

}



Item_maxmin_subselect::Item_maxmin_subselect(THD *thd_param,

                                             Item_subselect *parent,

					     st_select_lex *select_lex,

sql/item_subselect.h

+16 −0
Original line number Diff line number Diff line
@@ -126,6 +126,12 @@ class Item_subselect :public Item_result_field 
  enum_parsing_place place() { return parsing_place; }

  bool walk(Item_processor processor, bool walk_subquery, byte *arg);



  /**

    Get the SELECT_LEX structure associated with this Item.

    @return the SELECT_LEX structure associated with this Item

  */

  st_select_lex* get_select_lex();



  friend class select_subselect;

  friend class Item_in_optimizer;

  friend bool Item_field::fix_fields(THD *, Item **);
@@ -169,6 +175,16 @@ class Item_singlerow_subselect :public Item_subselect 
  bool null_inside();

  void bring_value();



  /**

    This method is used to implement a special case of semantic tree

    rewriting, mandated by a SQL:2003 exception in the specification.

    The only caller of this method is handle_sql2003_note184_exception(),

    see the code there for more details.

    Do not call this method for other purposes.

    @return the SELECT_LEX structure that was given in the constructor.

  */

  st_select_lex* invalidate_and_restore_select_lex();



  friend class select_singlerow_subselect;

};

sql/sql_yacc.yy

+98 −17
Original line number Diff line number Diff line
@@ -310,6 +310,81 @@ void case_stmt_action_end_case(LEX *lex, bool simple) 
  lex->sphead->do_cont_backpatch();

}



/**

  Helper to resolve the SQL:2003 Syntax exception 1) in <in predicate>.

  See SQL:2003, Part 2, section 8.4 <in predicate>, Note 184, page 383.

  This function returns the proper item for the SQL expression

  <code>left [NOT] IN ( expr )</code>

  @param thd the current thread

  @param left the in predicand

  @param equal true for IN predicates, false for NOT IN predicates

  @param expr first and only expression of the in value list

  @return an expression representing the IN predicate.

*/

Item* handle_sql2003_note184_exception(THD *thd, Item* left, bool equal,

                                       Item *expr)

{

  /*

    Relevant references for this issue:

    - SQL:2003, Part 2, section 8.4 <in predicate>, page 383,

    - SQL:2003, Part 2, section 7.2 <row value expression>, page 296,

    - SQL:2003, Part 2, section 6.3 <value expression primary>, page 174,

    - SQL:2003, Part 2, section 7.15 <subquery>, page 370,

    - SQL:2003 Feature F561, "Full value expressions".



    The exception in SQL:2003 Note 184 means:

    Item_singlerow_subselect, which corresponds to a <scalar subquery>,

    should be re-interpreted as an Item_in_subselect, which corresponds

    to a <table subquery> when used inside an <in predicate>.



    Our reading of Note 184 is reccursive, so that all:

    - IN (( <subquery> ))

    - IN ((( <subquery> )))

    - IN '('^N <subquery> ')'^N

    - etc

    should be interpreted as a <table subquery>, no matter how deep in the

    expression the <subquery> is.

  */



  Item *result;



  DBUG_ENTER("handle_sql2003_note184_exception");



  if (expr->type() == Item::SUBSELECT_ITEM)

  {

    Item_subselect *expr2 = (Item_subselect*) expr;



    if (expr2->substype() == Item_subselect::SINGLEROW_SUBS)

    {

      Item_singlerow_subselect *expr3 = (Item_singlerow_subselect*) expr2;

      st_select_lex *subselect;



      /*

        Implement the mandated change, by altering the semantic tree:

          left IN Item_singlerow_subselect(subselect)

        is modified to

          left IN (subselect)

        which is represented as

          Item_in_subselect(left, subselect)

      */

      subselect= expr3->invalidate_and_restore_select_lex();

      result= new (thd->mem_root) Item_in_subselect(left, subselect);



      if (! equal)

        result = negate_expression(thd, result);



      DBUG_RETURN(result);

    }

  }



  if (equal)

    result= new (thd->mem_root) Item_func_eq(left, expr);

  else

    result= new (thd->mem_root) Item_func_ne(left, expr);



  DBUG_RETURN(result);

}



%}

%union {

  int  num;
@@ -6169,28 +6244,34 @@ bool_pri: 


predicate:

          bit_expr IN_SYM '(' subselect ')'

	  { $$= new Item_in_subselect($1, $4); }

          {

            $$= new (YYTHD->mem_root) Item_in_subselect($1, $4);

          }

        | bit_expr not IN_SYM '(' subselect ')'

          { $$= negate_expression(YYTHD, new Item_in_subselect($1, $5)); }

          {

            THD *thd= YYTHD;

            Item *item= new (thd->mem_root) Item_in_subselect($1, $5);

            $$= negate_expression(thd, item);

          }

        | bit_expr IN_SYM '(' expr ')'

          {

              $$= new Item_func_eq($1, $4);

            $$= handle_sql2003_note184_exception(YYTHD, $1, true, $4);

          }

        | bit_expr IN_SYM '(' expr ',' expr_list ')'

          { 

            $6->push_front($4);

            $6->push_front($1);

              $$= new Item_func_in(*$6);

            $$= new (YYTHD->mem_root) Item_func_in(*$6);

          }

        | bit_expr not IN_SYM '(' expr ')'

          {

              $$= new Item_func_ne($1, $5);

            $$= handle_sql2003_note184_exception(YYTHD, $1, false, $5);

          }

        | bit_expr not IN_SYM '(' expr ',' expr_list ')'

          {

            $7->push_front($5);

            $7->push_front($1);

              Item_func_in *item = new Item_func_in(*$7);

            Item_func_in *item = new (YYTHD->mem_root) Item_func_in(*$7);

            item->negate();

            $$= item;

          }