MDEV-8860 Wrong result for WHERE 2016 < SOME (SELECT CAST(time_column AS DATETIME) FROM t1)

MDEV-8875 Wrong metadata for MAX(CAST(time_column AS DATETIME))

Author: Alexander Barkov

mysql-test/r/func_time.result

@@ -1726,7 +1726,7 @@ select 1 from t1 where 1 < some (select cast(a as datetime) from t1);
 1
 1
 Warnings:
-Warning	1292	Truncated incorrect DOUBLE value: '2001-01-01 00:01:00'
+Warning	1292	Incorrect datetime value: '1'
 drop table t1;
 SET timestamp=DEFAULT;
 select time('10:10:10') > 10;

mysql-test/r/type_datetime.result

@@ -1096,5 +1096,48 @@ Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where (coalesce(`test`.`t1`.`a`) = TIMESTAMP'2001-01-01 00:00:00')
 DROP TABLE t1;
 #
+# MDEV-8875 Wrong metadata for MAX(CAST(time_column AS DATETIME))
+#
+SET timestamp=UNIX_TIMESTAMP('2015-01-01 00:00:00');
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('00:00:00'),('00:01:00');
+SELECT MAX(CAST(a AS DATETIME)) FROM t1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					MAX(CAST(a AS DATETIME))	12	19	19	Y	128	0	63
+MAX(CAST(a AS DATETIME))
+2015-01-01 00:01:00
+CREATE TABLE t2 AS SELECT MAX(CAST(a AS DATETIME)) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `MAX(CAST(a AS DATETIME))` datetime DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
+SET timestamp=DEFAULT;
+#
+# MDEV-8860 Wrong result for WHERE 2016 < SOME (SELECT CAST(time_column AS DATETIME) FROM t1)
+#
+SET timestamp=UNIX_TIMESTAMP('2015-01-01 00:00:00');
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('00:00:00'),('00:01:00');
+SELECT 1 FROM t1 WHERE 2016 > SOME (SELECT CAST(a AS DATETIME) FROM t1);
+1
+Warnings:
+Warning	1292	Incorrect datetime value: '2016'
+SELECT * FROM t1 WHERE 2016 > CAST(a AS DATETIME);
+a
+Warnings:
+Warning	1292	Incorrect datetime value: '2016'
+SELECT 1 FROM t1 WHERE 20160101 > SOME (SELECT CAST(a AS DATETIME) FROM t1);
+1
+1
+1
+SELECT * FROM t1 WHERE 20160101 > CAST(a AS DATETIME);
+a
+00:00:00
+00:01:00
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #

mysql-test/t/type_datetime.test

@@ -663,6 +663,35 @@ INSERT INTO t1 VALUES ('2001-01-01 00:00:00'),('2001-01-02 00:00:00');
 EXPLAIN EXTENDED SELECT * FROM t1 WHERE COALESCE(a)=TIMESTAMP'2001-01-01 00:00:00' AND COALESCE(a)>=TIMESTAMP'2001-01-01 00:00:00';
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-8875 Wrong metadata for MAX(CAST(time_column AS DATETIME))
+--echo #
+SET timestamp=UNIX_TIMESTAMP('2015-01-01 00:00:00');
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('00:00:00'),('00:01:00');
+--disable_ps_protocol
+--enable_metadata
+SELECT MAX(CAST(a AS DATETIME)) FROM t1;
+--disable_metadata
+--enable_ps_protocol
+CREATE TABLE t2 AS SELECT MAX(CAST(a AS DATETIME)) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+DROP TABLE t1;
+SET timestamp=DEFAULT;
+
+--echo #
+--echo # MDEV-8860 Wrong result for WHERE 2016 < SOME (SELECT CAST(time_column AS DATETIME) FROM t1)
+--echo #
+SET timestamp=UNIX_TIMESTAMP('2015-01-01 00:00:00');
+CREATE TABLE t1 (a TIME);
+INSERT INTO t1 VALUES ('00:00:00'),('00:01:00');
+SELECT 1 FROM t1 WHERE 2016 > SOME (SELECT CAST(a AS DATETIME) FROM t1);
+SELECT * FROM t1 WHERE 2016 > CAST(a AS DATETIME);
+SELECT 1 FROM t1 WHERE 20160101 > SOME (SELECT CAST(a AS DATETIME) FROM t1);
+SELECT * FROM t1 WHERE 20160101 > CAST(a AS DATETIME);
+DROP TABLE t1;
+
 --echo #
 --echo # End of 10.1 tests
 --echo #

sql/item_sum.cc

@@ -1190,7 +1190,15 @@ Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
   decimals=item->decimals;
   with_subselect= args[0]->with_subselect;
 
-  switch (hybrid_type= item->result_type()) {
+  Item *item2= item->real_item();
+  if (item2->type() == Item::FIELD_ITEM)
+    set_handler_by_field_type(((Item_field*) item2)->field->type());
+  else if (item->cmp_type() == TIME_RESULT)
+    set_handler_by_field_type(item2->field_type());
+  else
+    set_handler_by_result_type(item2->result_type());
+
+  switch (Item_sum_hybrid::result_type()) {
   case INT_RESULT:
   case DECIMAL_RESULT:
   case STRING_RESULT:
@@ -1210,11 +1218,6 @@ Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
   result_field=0;
   null_value=1;
   fix_length_and_dec();
-  item= item->real_item();
-  if (item->type() == Item::FIELD_ITEM)
-    hybrid_field_type= ((Item_field*) item)->field->type();
-  else
-    hybrid_field_type= Item::field_type();
 
   if (check_sum_func(thd, ref))
     return TRUE;
@@ -2235,7 +2238,7 @@ void Item_sum_num::reset_field()
 
 void Item_sum_hybrid::reset_field()
 {
-  switch(hybrid_type) {
+  switch(Item_sum_hybrid::result_type()) {
   case STRING_RESULT:
   {
     char buff[MAX_FIELD_WIDTH];
@@ -2507,7 +2510,7 @@ Item *Item_sum_avg::result_item(THD *thd, Field *field)
 
 void Item_sum_hybrid::update_field()
 {
-  switch (hybrid_type) {
+  switch (Item_sum_hybrid::result_type()) {
   case STRING_RESULT:
     min_max_update_str_field();
     break;

sql/item_sum.h

@@ -1027,26 +1027,26 @@ class Item_sum_std :public Item_sum_variance
 // This class is a string or number function depending on num_func
 class Arg_comparator;
 class Item_cache;
-class Item_sum_hybrid :public Item_sum
+class Item_sum_hybrid :public Item_sum, public Type_handler_hybrid_field_type
 {
 protected:
   Item_cache *value, *arg_cache;
   Arg_comparator *cmp;
-  Item_result hybrid_type;
-  enum_field_types hybrid_field_type;
   int cmp_sign;
   bool was_values;  // Set if we have found at least one row (for max/min only)
   bool was_null_value;
 
   public:
   Item_sum_hybrid(THD *thd, Item *item_par,int sign):
-    Item_sum(thd, item_par), value(0), arg_cache(0), cmp(0),
-    hybrid_type(INT_RESULT), hybrid_field_type(MYSQL_TYPE_LONGLONG),
+    Item_sum(thd, item_par),
+    Type_handler_hybrid_field_type(MYSQL_TYPE_LONGLONG),
+    value(0), arg_cache(0), cmp(0),
     cmp_sign(sign), was_values(TRUE)
   { collation.set(&my_charset_bin); }
   Item_sum_hybrid(THD *thd, Item_sum_hybrid *item)
-    :Item_sum(thd, item), value(item->value), arg_cache(0),
-    hybrid_type(item->hybrid_type), hybrid_field_type(item->hybrid_field_type),
+    :Item_sum(thd, item),
+    Type_handler_hybrid_field_type(item),
+    value(item->value), arg_cache(0),
     cmp_sign(item->cmp_sign), was_values(item->was_values)
   { }
   bool fix_fields(THD *, Item **);
@@ -1058,8 +1058,12 @@ class Item_sum_hybrid :public Item_sum
   void reset_field();
   String *val_str(String *);
   bool keep_field_type(void) const { return 1; }
-  enum Item_result result_type () const { return hybrid_type; }
-  enum enum_field_types field_type() const { return hybrid_field_type; }
+  enum Item_result result_type () const
+  { return Type_handler_hybrid_field_type::result_type(); }
+  enum Item_result cmp_type () const
+  { return Type_handler_hybrid_field_type::cmp_type(); }
+  enum enum_field_types field_type() const
+  { return Type_handler_hybrid_field_type::field_type(); }
   void update_field();
   void min_max_update_str_field();
   void min_max_update_real_field();

sql/sql_type.h

@@ -270,6 +270,12 @@ class Type_handler_hybrid_field_type: public Type_handler
   const Type_handler *get_handler_by_field_type(enum_field_types type) const;
 public:
   Type_handler_hybrid_field_type();
+  Type_handler_hybrid_field_type(enum_field_types type)
+    :m_type_handler(get_handler_by_field_type(type))
+  { }
+  Type_handler_hybrid_field_type(const Type_handler_hybrid_field_type *other)
+    :m_type_handler(other->m_type_handler)
+  { }
   enum_field_types field_type() const { return m_type_handler->field_type(); }
   Item_result result_type() const { return m_type_handler->result_type(); }
   Item_result cmp_type() const { return m_type_handler->cmp_type(); }