Commit 761a88ee authored by iggy@rolltop.ignatz42.dyndns.org's avatar iggy@rolltop.ignatz42.dyndns.org
Browse files

Bug#20836 Selecting into variables results in wrong results being returned 

This error is displayed anytime the SELECT statement needs a temp table to
return correct results because the object (select_dumpvar) that represents
variables named in the INTO clause stored the results before the temp
table was considered.  The problem was fixed by creating the necessary
Item_func_set_user_var objects once the correct data is ready.
parent c2aca91b

mysql-test/r/distinct.result

+59 −0
Original line number Diff line number Diff line
@@ -566,3 +566,62 @@ a b 
3	2

2	3

DROP TABLE t1;

DROP TABLE IF EXISTS t1;

CREATE TABLE t1 (id INT NOT NULL, fruit_id INT NOT NULL, fruit_name varchar(20)

default NULL);

INSERT INTO t1 VALUES (1,1,'ORANGE');

INSERT INTO t1 VALUES (2,2,'APPLE');

INSERT INTO t1 VALUES (3,2,'APPLE');

INSERT INTO t1 VALUES (4,3,'PEAR');

SELECT DISTINCT fruit_id, fruit_name INTO @v1, @v2 FROM t1 WHERE fruit_name = 

'APPLE';

SELECT @v1, @v2;

@v1	@v2

2	APPLE

SELECT DISTINCT fruit_id, fruit_name INTO @v3, @v4 FROM t1 GROUP BY fruit_id, 

fruit_name HAVING fruit_name = 'APPLE';

SELECT @v3, @v4;

@v3	@v4

2	APPLE

SELECT DISTINCT @v5:= fruit_id, @v6:= fruit_name INTO @v7, @v8 FROM t1 WHERE 

fruit_name = 'APPLE';

SELECT @v5, @v6, @v7, @v8;

@v5	@v6	@v7	@v8

2	APPLE	2	APPLE

SELECT DISTINCT @v5 + fruit_id, CONCAT(@v6, fruit_name) INTO @v9, @v10 FROM t1 

WHERE fruit_name = 'APPLE';

SELECT @v5, @v6, @v7, @v8, @v9, @v10;

@v5	@v6	@v7	@v8	@v9	@v10

2	APPLE	2	APPLE	4	APPLEAPPLE

SELECT DISTINCT @v11:= @v5 + fruit_id, @v12:= CONCAT(@v6, fruit_name) INTO 

@v13, @v14 FROM t1 WHERE fruit_name = 'APPLE';

SELECT @v11, @v12, @v13, @v14;

@v11	@v12	@v13	@v14

4	APPLEAPPLE	4	APPLEAPPLE

SELECT DISTINCT @v13, @v14 INTO @v15, @v16 FROM t1 WHERE fruit_name = 'APPLE';

SELECT @v15, @v16;

@v15	@v16

4	APPLEAPPLE

SELECT DISTINCT 2 + 2, 'Bob' INTO @v17, @v18 FROM t1 WHERE fruit_name = 

'APPLE';

SELECT @v17, @v18;

@v17	@v18

4	Bob

DROP TABLE IF EXISTS t2;

CREATE TABLE t2 (fruit_id INT NOT NULL, fruit_name varchar(20)

default NULL);

SELECT DISTINCT fruit_id, fruit_name INTO OUTFILE 

'../tmp/data1.tmp' FROM t1 WHERE fruit_name = 'APPLE';

LOAD DATA INFILE '../tmp/data1.tmp' INTO TABLE t2;

SELECT DISTINCT @v19:= fruit_id, @v20:= fruit_name INTO OUTFILE 

'../tmp/data2.tmp' FROM t1 WHERE fruit_name = 'APPLE';

LOAD DATA INFILE '../tmp/data2.tmp' INTO TABLE t2;

SELECT @v19, @v20;

@v19	@v20

2	APPLE

SELECT * FROM t2;

fruit_id	fruit_name

2	APPLE

2	APPLE

DROP TABLE t1;

DROP TABLE t2;

mysql-test/t/distinct.test

+65 −0
Original line number Diff line number Diff line
@@ -389,4 +389,69 @@ explain SELECT DISTINCT a, b FROM t1 ORDER BY b; 
SELECT DISTINCT a, b FROM t1 ORDER BY b;

DROP TABLE t1;



#

#Bug #20836: Selecting into variables results in wrong results being returned

#

--disable_warnings

DROP TABLE IF EXISTS t1;

--enable_warnings



CREATE TABLE t1 (id INT NOT NULL, fruit_id INT NOT NULL, fruit_name varchar(20)

default NULL);



INSERT INTO t1 VALUES (1,1,'ORANGE');

INSERT INTO t1 VALUES (2,2,'APPLE');

INSERT INTO t1 VALUES (3,2,'APPLE');

INSERT INTO t1 VALUES (4,3,'PEAR');



SELECT DISTINCT fruit_id, fruit_name INTO @v1, @v2 FROM t1 WHERE fruit_name = 

'APPLE';

SELECT @v1, @v2;



SELECT DISTINCT fruit_id, fruit_name INTO @v3, @v4 FROM t1 GROUP BY fruit_id, 

fruit_name HAVING fruit_name = 'APPLE';

SELECT @v3, @v4;



SELECT DISTINCT @v5:= fruit_id, @v6:= fruit_name INTO @v7, @v8 FROM t1 WHERE 

fruit_name = 'APPLE';

SELECT @v5, @v6, @v7, @v8;



SELECT DISTINCT @v5 + fruit_id, CONCAT(@v6, fruit_name) INTO @v9, @v10 FROM t1 

WHERE fruit_name = 'APPLE';

SELECT @v5, @v6, @v7, @v8, @v9, @v10;



SELECT DISTINCT @v11:= @v5 + fruit_id, @v12:= CONCAT(@v6, fruit_name) INTO 

@v13, @v14 FROM t1 WHERE fruit_name = 'APPLE';

SELECT @v11, @v12, @v13, @v14;



SELECT DISTINCT @v13, @v14 INTO @v15, @v16 FROM t1 WHERE fruit_name = 'APPLE';

SELECT @v15, @v16;



SELECT DISTINCT 2 + 2, 'Bob' INTO @v17, @v18 FROM t1 WHERE fruit_name = 

'APPLE';

SELECT @v17, @v18;



--disable_warnings

DROP TABLE IF EXISTS t2;

--enable_warnings



CREATE TABLE t2 (fruit_id INT NOT NULL, fruit_name varchar(20)

default NULL);



SELECT DISTINCT fruit_id, fruit_name INTO OUTFILE 

'../tmp/data1.tmp' FROM t1 WHERE fruit_name = 'APPLE';

LOAD DATA INFILE '../tmp/data1.tmp' INTO TABLE t2;

--exec rm $MYSQL_TEST_DIR/var/tmp/data1.tmp



SELECT DISTINCT @v19:= fruit_id, @v20:= fruit_name INTO OUTFILE 

'../tmp/data2.tmp' FROM t1 WHERE fruit_name = 'APPLE';

LOAD DATA INFILE '../tmp/data2.tmp' INTO TABLE t2;

--exec rm $MYSQL_TEST_DIR/var/tmp/data2.tmp



SELECT @v19, @v20;

SELECT * FROM t2;



DROP TABLE t1;

DROP TABLE t2;



# End of 4.1 tests

sql/sql_class.cc

+22 −26
Original line number Diff line number Diff line
@@ -1372,36 +1372,19 @@ bool select_exists_subselect::send_data(List<Item> &items) 


int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)

{

  List_iterator_fast<Item> li(list);

  List_iterator_fast<LEX_STRING> gl(var_list);

  Item *item;

  LEX_STRING *ls;

  unit= u;

  

  if (var_list.elements != list.elements)

  {

    my_error(ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT, MYF(0));

    return 1;

  }

  unit=u;

  while ((item=li++))

  {

    ls= gl++;

    Item_func_set_user_var *xx = new Item_func_set_user_var(*ls,item);

    /*

      Item_func_set_user_var can't substitute something else on its place =>

      0 can be passed as last argument (reference on item)

    */

    xx->fix_fields(thd,(TABLE_LIST*) thd->lex->select_lex.table_list.first,

		   0);

    xx->fix_length_and_dec();

    vars.push_back(xx);

  }

  return 0;

}





void select_dumpvar::cleanup()

{

  vars.empty();

  row_count= 0;

}
@@ -1744,12 +1727,14 @@ Statement_map::~Statement_map() 


bool select_dumpvar::send_data(List<Item> &items)

{

  List_iterator_fast<Item_func_set_user_var> li(vars);

  Item_func_set_user_var *xx;

  List_iterator_fast<LEX_STRING> var_li(var_list);

  List_iterator<Item> it(items);

  Item *item;

  LEX_STRING *ls;

  DBUG_ENTER("send_data");



  if (unit->offset_limit_cnt)

  {				          // Using limit offset,count

  {						// using limit offset,count

    unit->offset_limit_cnt--;

    DBUG_RETURN(0);

  }
@@ -1758,10 +1743,21 @@ bool select_dumpvar::send_data(List<Item> &items) 
    my_error(ER_TOO_MANY_ROWS, MYF(0));

    DBUG_RETURN(1);

  }

  while ((xx=li++))

  while ((ls= var_li++) && (item= it++))

  {

    xx->check();

    xx->update();

    Item_func_set_user_var *suv= new Item_func_set_user_var(*ls, item);



    /*

      Item_func_set_user_var can't substitute something else on its

      place => NULL may be passed as last argument (reference on

      item) Item_func_set_user_var can't be fixed after creation, so

      we do not check var->fixed

    */



    suv->fix_fields(thd, (TABLE_LIST *) thd->lex->select_lex.table_list.first,

            0);

    suv->check();

    suv->update();  

  }

  DBUG_RETURN(0);

}

sql/sql_class.h

+1 −2
Original line number Diff line number Diff line
@@ -1573,8 +1573,7 @@ class select_dumpvar :public select_result_interceptor { 
  ha_rows row_count;

public:

  List<LEX_STRING> var_list;

  List<Item_func_set_user_var> vars;

  select_dumpvar(void)  { var_list.empty(); vars.empty(); row_count=0;}

  select_dumpvar()  { var_list.empty(); row_count= 0;}

  ~select_dumpvar() {}

  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);

  bool send_data(List<Item> &items);