diff options
| -rw-r--r-- | mysql-test/r/union.result | 24 | ||||
| -rw-r--r-- | mysql-test/t/union.test | 22 | ||||
| -rw-r--r-- | sql/field.cc | 3 | ||||
| -rw-r--r-- | sql/field.h | 10 | ||||
| -rw-r--r-- | sql/item.cc | 4 | ||||
| -rw-r--r-- | sql/sql_select.cc | 2 |
6 files changed, 64 insertions, 1 deletions
diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result index a8f538b6cc7..295451867c8 100644 --- a/mysql-test/r/union.result +++ b/mysql-test/r/union.result @@ -1496,4 +1496,28 @@ UNION SELECT 1,1; ERROR HY000: Incorrect usage of UNION and ORDER BY DROP TABLE t1,t2; +CREATE TABLE t1 (a INT); +INSERT INTO t1 VALUES (1), (2), (3); +CREATE TABLE t2 SELECT * FROM (SELECT NULL) a UNION SELECT a FROM t1; +DESC t2; +Field Type Null Key Default Extra +NULL int(11) YES NULL +CREATE TABLE t3 SELECT a FROM t1 UNION SELECT * FROM (SELECT NULL) a; +DESC t3; +Field Type Null Key Default Extra +a int(11) YES NULL +CREATE TABLE t4 SELECT NULL; +DESC t4; +Field Type Null Key Default Extra +NULL binary(0) YES NULL +CREATE TABLE t5 SELECT NULL UNION SELECT NULL; +DESC t5; +Field Type Null Key Default Extra +NULL binary(0) YES NULL +CREATE TABLE t6 +SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1; +DESC t6; +Field Type Null Key Default Extra +NULL int(11) YES NULL +DROP TABLE t1, t2, t3, t4, t5, t6; End of 5.0 tests diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test index 0f8ba1aeae0..70789404d6e 100644 --- a/mysql-test/t/union.test +++ b/mysql-test/t/union.test @@ -966,4 +966,26 @@ SELECT 1,1; DROP TABLE t1,t2; +# Bug#32848: Data type conversion bug in union subselects in MySQL 5.0.38 +# +CREATE TABLE t1 (a INT); +INSERT INTO t1 VALUES (1), (2), (3); + +CREATE TABLE t2 SELECT * FROM (SELECT NULL) a UNION SELECT a FROM t1; +DESC t2; + +CREATE TABLE t3 SELECT a FROM t1 UNION SELECT * FROM (SELECT NULL) a; +DESC t3; + +CREATE TABLE t4 SELECT NULL; +DESC t4; + +CREATE TABLE t5 SELECT NULL UNION SELECT NULL; +DESC t5; + +CREATE TABLE t6 +SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1; +DESC t6; + +DROP TABLE t1, t2, t3, t4, t5, t6; --echo End of 5.0 tests diff --git a/sql/field.cc b/sql/field.cc index 52168e713aa..668ced4a229 100644 --- a/sql/field.cc +++ b/sql/field.cc @@ -1307,7 +1307,8 @@ Field::Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg, field_name(field_name_arg), key_start(0), part_of_key(0), part_of_key_not_clustered(0), part_of_sortkey(0), unireg_check(unireg_check_arg), - field_length(length_arg), null_bit(null_bit_arg) + field_length(length_arg), null_bit(null_bit_arg), + is_created_from_null_item(FALSE) { flags=null_ptr ? 0: NOT_NULL_FLAG; comment.str= (char*) ""; diff --git a/sql/field.h b/sql/field.h index 27be2601270..dc4f1b13cb5 100644 --- a/sql/field.h +++ b/sql/field.h @@ -90,6 +90,16 @@ public: uint32 flags; uint16 field_index; // field number in fields array uchar null_bit; // Bit used to test null bit + /** + If true, this field was created in create_tmp_field_from_item from a NULL + value. This means that the type of the field is just a guess, and the type + may be freely coerced to another type. + + @see create_tmp_field_from_item + @see Item_type_holder::get_real_type + + */ + bool is_created_from_null_item; Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg, uchar null_bit_arg, utype unireg_check_arg, diff --git a/sql/item.cc b/sql/item.cc index 4d579597d21..a8b17a5ca12 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -6707,6 +6707,8 @@ enum_field_types Item_type_holder::get_real_type(Item *item) */ Field *field= ((Item_field *) item)->field; enum_field_types type= field->real_type(); + if (field->is_created_from_null_item) + return MYSQL_TYPE_NULL; /* work around about varchar type field detection */ if (type == MYSQL_TYPE_STRING && field->type() == MYSQL_TYPE_VAR_STRING) return MYSQL_TYPE_VAR_STRING; @@ -6965,6 +6967,8 @@ Field *Item_type_holder::make_field_by_type(TABLE *table) if (field) field->init(table); return field; + case MYSQL_TYPE_NULL: + return make_string_field(table); default: break; } diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 3a142568080..741e8afec1d 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -9277,6 +9277,8 @@ static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table, *((*copy_func)++) = item; // Save for copy_funcs if (modify_item) item->set_result_field(new_field); + if (item->type() == Item::NULL_ITEM) + new_field->is_created_from_null_item= TRUE; return new_field; } |