MySQL Bugs: #29457: mysql: -T option no longer works in 5.1 (add -m option)

Bug #29457	mysql: -T option no longer works in 5.1 (add -m option)
Submitted:	30 Jun 2007 15:39	Modified:	25 May 2010 16:24
Reporter:	Paul DuBois	Email Updates:
Status:	Won't fix	Impact on me:	None
Category:	MySQL Server: Command-line Clients	Severity:	S4 (Feature request)
Version:	5.1	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
The -T option causes mysql to display query metadata.
This option no longer works in MySQL 5.1. The problem
appears to surface in 5.1.14.

How to repeat:
First, establish that -T works in MySQL 4.1 and 5.0 (I install various
releases under /var/mysql/RELEASE/):

% /var/mysql/40124/bin/mysql -T -e "SELECT 1"
Catalog:    'def'
Database:   ''
Table:      ''
Name:       '1'
Type:       8
Length:     1
Max length: 1
Is_null:    0
Flags:      32897
Decimals:   0

+---+
| 1 |
+---+
| 1 |
+---+

% /var/mysql/50046/bin/mysql -T -e "SELECT 1"
Field   1:  `1`
Catalog:    `def`
Database:   ``
Table:      ``
Org_table:  ``
Type:       LONGLONG
Collation:  binary (63)
Length:     1
Max_length: 1
Decimals:   0
Flags:      NOT_NULL BINARY NUM 

+---+
| 1 |
+---+
| 1 | 
+---+

Next, establish that -T does not work in 5.1, and appears
to stop working with 5.1.14:

% /var/mysql/50113/bin/mysql -T -e "SELECT 1"
Field   1:  `1`
Catalog:    `def`
Database:   ``
Table:      ``
Org_table:  ``
Type:       LONGLONG
Collation:  binary (63)
Length:     1
Max_length: 1
Decimals:   0
Flags:      NOT_NULL BINARY NUM 

+---+
| 1 |
+---+
| 1 | 
+---+

% /var/mysql/50114/bin/mysql -T -e "SELECT 1"
+---+
| 1 |
+---+
| 1 | 
+---+

Thank you for a bug report. Verified just as described with mysql from latest 5.1.21-BK on Linux.

Looks like it has changed:

[miguel@light 5.1]$ bin/mysql -uroot --column-type-info -e "select version()"
Field   1:  `version()`
Catalog:    `def`
Database:   ``
Table:      ``
Org_table:  ``
Type:       VAR_STRING
Collation:  latin1_swedish_ci (8)
Length:     17
Max_length: 17
Decimals:   31
Flags:      NOT_NULL 

+-------------------+
| version()         |
+-------------------+
| 5.1.21-beta-debug | 
+-------------------+
[miguel@light 5.1]$

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/31920

ChangeSet@1.2562, 2007-07-31 15:50:28-04:00, dkatz@damien-katzs-computer.local +2 -0
  Bug #29457 mysql: -T option no longer works in 5.1
  
  In client/mysql.cc, changed option -T to be an alias for option --column-type-info instead of --debug-info. The reasoning behind the change is because most uses of -T is to get column information, not the debug information.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/31923

ChangeSet@1.2562, 2007-07-31 16:08:59-04:00, dkatz@damien-katzs-computer.local +3 -0
  Bug #29457 mysql: -T option no longer works in 5.1
  
  In client/mysql.cc, changed option -T to be an alias for option --column-type-info instead of --debug-info. The reasoning behind the change is because most uses of -T is to get column information, not the debug information.

This bug is confused with bug #30127, which caused --debug-info to not print summary information at exit.  So, the only visible effect of --debug-info was to print the column metadata info.

Also unfortunate is the fact that --column-type-info was automatically turned on with --debug-info, which was not part of the documented behavior of --debug-info.

There's no way to clean this up entirely without changing some behavior.  -T has always been documented as a shortcut for --debug-info, and we'll keep it that way.  However, --column-type-info is handy enough to want a shortcut for it, and we will add -m for that purpose.

In summary, MySQL 5.1 will (once -m is added) behave like:

--column-type-info or -m == display column metadata info before query results
--debug-check            == report problems (memory leaks, etc.) at program end
--debug-info or -T       == like --debug-check, but also display statistics info

I'm downgrading this bug to a feature request (to add -m shortcut for --column-type-info).

I'm withdrawing this as a feature request. The report is old and no one has complained about lack of -m.