Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.0(EOL), 10.1(EOL), 10.2(EOL), 10.3(EOL)
Description
DROP TABLE IF EXISTS t1; |
SET @a='test'; |
SELECT @a; |
Field 1: `@a`
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Catalog: `def`
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Database: ``
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Table: ``
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Org_table: ``
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Type: MEDIUM_BLOB
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Collation: utf8_general_ci (33)
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Length: 50331645
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Max_length: 4
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Decimals: 31
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Flags:
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+------+
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| @a |
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+------+
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| test |
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+------+
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Notice, MEDIUM_BLOB is displayed as the data type.
Now I create a table:
DROP TABLE IF EXISTS t1; |
CREATE TABLE t1 AS SELECT @a; |
SHOW CREATE TABLE t1; |
+-------+-----------------------------------------------------------------------------------------------+
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| Table | Create Table |
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+-------+-----------------------------------------------------------------------------------------------+
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| t1 | CREATE TABLE `t1` (
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`@a` longtext CHARACTER SET utf8
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) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
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+-------+-----------------------------------------------------------------------------------------------+
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Notice, a LONGTEXT column was created.
There is a mismatch:
- Either LONG_BLOB should be reported in the metadata
- Or a MEDIUMBLOB column should be created
- Or perhaps a smaller data type could be used, e.g. BLOB or TINYBLOB, with the corresponding data type displayed in metadata.
Update:
The data type should be LONGBLOB/LONGTEXT, because user variables can be modified on the fly. So the metadata should by synchronized with the data type and report LONG_BLOB.
The same problem is repeatable with Item_func_set_user_var:
CREATE OR REPLACE TABLE t1 AS SELECT @a:=1; |
DESCRIBE t1;
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+-------+--------+------+-----+---------+-------+
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| Field | Type | Null | Key | Default | Extra |
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+-------+--------+------+-----+---------+-------+
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| @a:=1 | int(1) | NO | | 0 | |
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+-------+--------+------+-----+---------+-------+
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But if I start mysql --column-type-info test and do:
SELECT @a:=1; |
Field 1: `@a:=1`
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Type: LONGLONG
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Length: 3
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Max_length: 1
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Notice, result set metadata is wrong. It should report LONG rather than LONGLONG.
Attachments
Issue Links
- blocks
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MDEV-4912 Data type plugin API version 1
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- Closed
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