Commit 5f6df1b2 authored by igor@olga.mysql.com's avatar igor@olga.mysql.com
Browse files

Fix bug #30219. 

This bug manifested itself for queries with grouping by columns of
the BIT type. It led to wrong comparisons of bit-field values and
wrong result sets.
Bit-field values never cannot be compared as binary values. Yet
the class Field_bit had an implementation of the cmp method that
compared bit-fields values as binary values. 
Also the get_image and set_image methods of the base class Field 
cannot be used for objects of the Field_bit class. 
Now these methods are declared as virtual and specific implementations
of the methods are provided for the class Field_bit.
parent 2bfbe2cd

mysql-test/r/type_bit.result

+32 −0
Original line number Diff line number Diff line
@@ -618,4 +618,36 @@ bit_field int_field 
	2

handler t1 close;

drop table t1;

CREATE TABLE t1 (b BIT(2));

INSERT INTO t1 (b) VALUES (1), (3), (0), (3);

SELECT b+0, COUNT(DISTINCT b) FROM t1 GROUP BY b;

b+0	COUNT(DISTINCT b)

0	1

1	1

3	1

DROP TABLE t1;

CREATE TABLE t1 (b BIT(2), a VARCHAR(5));

INSERT INTO t1 (b, a) VALUES (1, "x"), (3, "zz"), (0, "y"), (3, "z");

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

b+0	COUNT(DISTINCT a)

0	1

1	1

3	2

DROP TABLE t1;

CREATE TABLE t1 (a CHAR(5), b BIT(2));

INSERT INTO t1 (b, a) VALUES (1, "x"), (3, "zz"), (0, "y"), (3, "z");

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

b+0	COUNT(DISTINCT a)

0	1

1	1

3	2

DROP TABLE t1;

CREATE TABLE t1 (a INT, b BIT(2));

INSERT INTO t1 (b, a) VALUES (1, 1), (3, 2), (0, 3), (3, 4);

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

b+0	COUNT(DISTINCT a)

0	1

1	1

3	2

DROP TABLE t1;

End of 5.0 tests

mysql-test/t/type_bit.test

+24 −0
Original line number Diff line number Diff line
@@ -272,4 +272,28 @@ handler t1 read a=(1); 
handler t1 close;

drop table t1;



#

# Bug #30219: GROUP BY a column of the BIT type

#



CREATE TABLE t1 (b BIT(2));

INSERT INTO t1 (b) VALUES (1), (3), (0), (3);

SELECT b+0, COUNT(DISTINCT b) FROM t1 GROUP BY b;

DROP TABLE t1;



CREATE TABLE t1 (b BIT(2), a VARCHAR(5));

INSERT INTO t1 (b, a) VALUES (1, "x"), (3, "zz"), (0, "y"), (3, "z");

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

DROP TABLE t1;



CREATE TABLE t1 (a CHAR(5), b BIT(2));

INSERT INTO t1 (b, a) VALUES (1, "x"), (3, "zz"), (0, "y"), (3, "z");

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

DROP TABLE t1;



CREATE TABLE t1 (a INT, b BIT(2));

INSERT INTO t1 (b, a) VALUES (1, 1), (3, 2), (0, 3), (3, 4);

SELECT b+0, COUNT(DISTINCT a) FROM t1 GROUP BY b;

DROP TABLE t1;



--echo End of 5.0 tests

sql/field.h

+10 −3
Original line number Diff line number Diff line
@@ -231,9 +231,9 @@ class Field 
    if (null_ptr)

      null_ptr=ADD_TO_PTR(null_ptr,ptr_diff,uchar*);

  }

  inline void get_image(char *buff,uint length, CHARSET_INFO *cs)

  virtual void get_image(char *buff, uint length, CHARSET_INFO *cs)

    { memcpy(buff,ptr,length); }

  inline void set_image(char *buff,uint length, CHARSET_INFO *cs)

  virtual void set_image(char *buff,uint length, CHARSET_INFO *cs)

    { memcpy(ptr,buff,length); }
@@ -1430,13 +1430,20 @@ class Field_bit :public Field { 
  String *val_str(String*, String *);

  my_decimal *val_decimal(my_decimal *);

  int cmp(const char *a, const char *b)

  { return cmp_binary(a, b); }

  { 

    DBUG_ASSERT(ptr == a);

    return Field_bit::key_cmp(b, bytes_in_rec+test(bit_len));

  }

  int key_cmp(const byte *a, const byte *b)

  { return cmp_binary((char *) a, (char *) b); }

  int key_cmp(const byte *str, uint length);

  int cmp_offset(uint row_offset);

  int cmp_binary_offset(uint row_offset)

  { return cmp_offset(row_offset); }

  void get_image(char *buff, uint length, CHARSET_INFO *cs)

  { get_key_image(buff, length, itRAW); }   

  void set_image(char *buff,uint length, CHARSET_INFO *cs)

  { Field_bit::store(buff, length, cs); }

  uint get_key_image(char *buff, uint length, imagetype type);

  void set_key_image(char *buff, uint length)

  { Field_bit::store(buff, length, &my_charset_bin); }