[#MDEV-12886] Different data type and default for INT and BIGINT columns in a VIEW for a SELECT with ROLLUP

I run this script:

CREATE OR REPLACE TABLE t1 (a int(11) NOT NULL);

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

CREATE OR REPLACE VIEW v1 AS SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;

DESCRIBE v1;

+-----------+------------+------+-----+---------+-------+

| Field     | Type       | Null | Key | Default | Extra |

+-----------+------------+------+-----+---------+-------+

| a         | bigint(11) | YES  |     | NULL    |       |

| LENGTH(a) | bigint(10) | YES  |     | NULL    |       |

| COUNT(*)  | bigint(21) | NO   |     | 0       |       |

+-----------+------------+------+-----+---------+-------+

Notice, it reports the data type of v1.a as BIGINT for some reasons. The expected data type is INT.

Now I change the data type from int to bigint:

CREATE OR REPLACE TABLE t1 (a bigint(11) NOT NULL);

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

CREATE OR REPLACE VIEW v1 AS SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;

DESCRIBE v1;

+-----------+------------+------+-----+---------+-------+

| Field     | Type       | Null | Key | Default | Extra |

+-----------+------------+------+-----+---------+-------+

| a         | bigint(20) | YES  |     | 0       |       |

| LENGTH(a) | bigint(10) | YES  |     | NULL    |       |

| COUNT(*)  | bigint(21) | NO   |     | 0       |       |

+-----------+------------+------+-----+---------+-------+

Notice, field "a" has different default:

Looks suspicious.

The difference happens because int does not pass this condition, while bigint does:

    if (orig_type != Item::DEFAULT_VALUE_ITEM && field->field->eq_def(result))

      *default_field= field->field;

See sql_select.cc, create_tmp_field().

[MDEV-12886] Different data type and default for INT and BIGINT columns in a VIEW for a SELECT with ROLLUP Created: 2017-05-24 Updated: 2017-05-27 Resolved: 2017-05-25
Status:	Closed
Project:	MariaDB Server
Component/s:	Views
Affects Version/s:	10.0, 10.1, 10.2, 10.3
Fix Version/s:	10.3.1