Commit 490ec62b authored by gkodinov/kgeorge@magare.gmz's avatar gkodinov/kgeorge@magare.gmz
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Bug #31887: DML Select statement not returning same results 

when executed in version 5

Zero fill is a field attribute only. So we can't always 
propagate  constants for zerofill fields : the values and 
expression results don't have that flag.

Fixed by converting the const value to a string and 
using that in const propagation when the context allows it. 
Disable const propagation for fields with ZEROFILL flag in
all the other cases.
parent cbc91811

mysql-test/r/compare.result

+38 −0
Original line number Diff line number Diff line
@@ -53,3 +53,41 @@ a b 
Warnings:

Warning	1292	Truncated incorrect DOUBLE value: ''

drop table if exists t1;

CREATE TABLE  t1 (b int(2) zerofill, c int(2) zerofill);

INSERT INTO t1 (b,c) VALUES (1,2), (1,1), (2,2);

SELECT CONCAT(b,c), CONCAT(b,c) = '0101' FROM t1;

CONCAT(b,c)	CONCAT(b,c) = '0101'

0102	0

0101	1

0202	0

EXPLAIN EXTENDED SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where

Warnings:

Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where ((`test`.`t1`.`b` = 1) and (concat(_binary'01',`test`.`t1`.`c`) = _latin1'0101'))

SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';

b	c

01	01

CREATE TABLE t2 (a int);

INSERT INTO t2 VALUES (1),(2);

SELECT a, 

(SELECT COUNT(*) FROM t1 

WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 

FROM t2 ORDER BY a;

a	x

1	1

2	0

EXPLAIN EXTENDED 

SELECT a, 

(SELECT COUNT(*) FROM t1 

WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 

FROM t2 ORDER BY a;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using filesort

2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where

Warnings:

Note	1276	Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1

Note	1276	Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1

Note	1003	select `test`.`t2`.`a` AS `a`,(select count(0) AS `COUNT(*)` from `test`.`t1` where ((`test`.`t1`.`b` = `test`.`t2`.`a`) and (concat(`test`.`t1`.`b`,`test`.`t1`.`c`) = concat(_latin1'0',`test`.`t2`.`a`,_latin1'01')))) AS `x` from `test`.`t2` order by `test`.`t2`.`a`

DROP TABLE t1,t2;

End of 5.0 tests

mysql-test/t/compare.test

+31 −0
Original line number Diff line number Diff line
@@ -46,3 +46,34 @@ insert into t1 values (0x01,0x01); 
select * from t1 where a=b;

select * from t1 where a=b and b=0x01;

drop table if exists t1;



#

# Bug #31887: DML Select statement not returning same results when executed

# in version 5

#



CREATE TABLE  t1 (b int(2) zerofill, c int(2) zerofill);

INSERT INTO t1 (b,c) VALUES (1,2), (1,1), (2,2);



SELECT CONCAT(b,c), CONCAT(b,c) = '0101' FROM t1;



EXPLAIN EXTENDED SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';

SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';



CREATE TABLE t2 (a int);

INSERT INTO t2 VALUES (1),(2);



SELECT a, 

  (SELECT COUNT(*) FROM t1 

   WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 

FROM t2 ORDER BY a;



EXPLAIN EXTENDED 

SELECT a, 

  (SELECT COUNT(*) FROM t1 

   WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 

FROM t2 ORDER BY a;



DROP TABLE t1,t2;



--echo End of 5.0 tests

sql/item.cc

+31 −0
Original line number Diff line number Diff line
@@ -4072,6 +4072,30 @@ bool Item_field::subst_argument_checker(byte **arg) 
}





/**

  Convert a numeric value to a zero-filled string



  @param[in,out]  item   the item to operate on

  @param          field  The field that this value is equated to



  This function converts a numeric value to a string. In this conversion

  the zero-fill flag of the field is taken into account.

  This is required so the resulting string value can be used instead of

  the field reference when propagating equalities.

*/



static void convert_zerofill_number_to_string(Item **item, Field_num *field)

{

  char buff[MAX_FIELD_WIDTH],*pos;

  String tmp(buff,sizeof(buff), field->charset()), *res;



  res= (*item)->val_str(&tmp);

  field->prepend_zeros(res);

  pos= (char *) sql_strmake (res->ptr(), res->length());

  *item= new Item_string(pos, res->length(), field->charset());

}





/*

  Set a pointer to the multiple equality the field reference belongs to

  (if any)
@@ -4120,6 +4144,13 @@ Item *Item_field::equal_fields_propagator(byte *arg) 
  if (!item ||

      (cmp_context != (Item_result)-1 && item->cmp_context != cmp_context))

    item= this;

  else if (field && (field->flags & ZEROFILL_FLAG) && IS_NUM(field->type()))

  {

    if (item && cmp_context != INT_RESULT)

      convert_zerofill_number_to_string(&item, (Field_num *)field);

    else

      item= this;

  }

  return item;

}

sql/mysql_priv.h

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ extern const char *primary_key_name; 
#include "mysql_com.h"

#include <violite.h>

#include "unireg.h"

#define IS_NUM(t)	((t) <= FIELD_TYPE_INT24 || (t) == FIELD_TYPE_YEAR || (t) == FIELD_TYPE_NEWDECIMAL)



void init_sql_alloc(MEM_ROOT *root, uint block_size, uint pre_alloc_size);

gptr sql_alloc(unsigned size);