Commit e7520c4b authored by Gleb Shchepa's avatar Gleb Shchepa
Browse files

Bug #39283: Date returned as VARBINARY to client for queries 

            with COALESCE and JOIN

The server returned to a client the VARBINARY column type
instead of the DATE type for a result of the COALESCE,
IFNULL, IF, CASE, GREATEST or LEAST functions if that result
was filesorted in an anonymous temporary table during
the query execution.

For example:
  SELECT COALESCE(t1.date1, t2.date2) AS result
    FROM t1 JOIN t2 ON t1.id = t2.id ORDER BY result;


To create a column of various date/time types in a
temporary table the create_tmp_field_from_item() function
uses the Item::tmp_table_field_from_field_type() method
call. However, fields of the MYSQL_TYPE_NEWDATE type were
missed there, and the VARBINARY columns were created
by default.
Necessary condition has been added.
parent c3d3f3ec

mysql-test/r/metadata.result

+17 −0
Original line number Diff line number Diff line
@@ -181,4 +181,21 @@ c1 c2 
3	3

DROP VIEW v1,v2;

DROP TABLE t1,t2;

CREATE TABLE t1 (i INT, d DATE);

INSERT INTO t1 VALUES (1, '2008-01-01'), (2, '2008-01-02'), (3, '2008-01-03');

SELECT COALESCE(d, d), IFNULL(d, d), IF(i, d, d),

CASE i WHEN i THEN d ELSE d END, GREATEST(d, d), LEAST(d, d)

FROM t1 ORDER BY RAND();

Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr

2008-01-01	2008-01-01	2008-01-01	2008-01-01	2008-01-01	2008-01-01

2008-01-02	2008-01-02	2008-01-02	2008-01-02	2008-01-02	2008-01-02

2008-01-03	2008-01-03	2008-01-03	2008-01-03	2008-01-03	2008-01-03

COALESCE(d, d)	IFNULL(d, d)	IF(i, d, d)	CASE i WHEN i THEN d ELSE d END	GREATEST(d, d)	LEAST(d, d)

def				CASE i WHEN i THEN d ELSE d END	CASE i WHEN i THEN d ELSE d END	10	10	10	Y	128	0	63

def				COALESCE(d, d)	COALESCE(d, d)	10	10	10	Y	128	0	63

def				GREATEST(d, d)	GREATEST(d, d)	10	10	10	Y	128	0	63

def				IF(i, d, d)	IF(i, d, d)	10	10	10	Y	128	0	63

def				IFNULL(d, d)	IFNULL(d, d)	10	10	10	Y	128	0	63

def				LEAST(d, d)	LEAST(d, d)	10	10	10	Y	128	0	63

DROP TABLE t1;

End of 5.0 tests

mysql-test/t/metadata.test

+17 −0
Original line number Diff line number Diff line
@@ -112,4 +112,21 @@ SELECT v1.c1, v2.c2 FROM v1 JOIN v2 ON c1=c2 GROUP BY v1.c1 ORDER BY v2.c2; 
DROP VIEW v1,v2;

DROP TABLE t1,t2;



#

# Bug #39283: Date returned as VARBINARY to client for queries

#             with COALESCE and JOIN

#



CREATE TABLE t1 (i INT, d DATE);

INSERT INTO t1 VALUES (1, '2008-01-01'), (2, '2008-01-02'), (3, '2008-01-03');



--enable_metadata

--sorted_result

SELECT COALESCE(d, d), IFNULL(d, d), IF(i, d, d),

       CASE i WHEN i THEN d ELSE d END, GREATEST(d, d), LEAST(d, d)

  FROM t1 ORDER BY RAND(); # force filesort

--disable_metadata



DROP TABLE t1;



--echo End of 5.0 tests

sql/sql_select.cc

+1 −0
Original line number Diff line number Diff line
@@ -8964,6 +8964,7 @@ static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table, 
    */

    if ((type= item->field_type()) == MYSQL_TYPE_DATETIME ||

        type == MYSQL_TYPE_TIME || type == MYSQL_TYPE_DATE ||

        type == MYSQL_TYPE_NEWDATE ||

        type == MYSQL_TYPE_TIMESTAMP || type == MYSQL_TYPE_GEOMETRY)

      new_field= item->tmp_table_field_from_field_type(table);

    /*