Terminating a MySQL query with \G
instead of ;
will cause MySQL to return the result set in vertical format, which is sometimes easier to read if the number of returned columns is large.
Example:
mysql> SELECT * FROM help_keyword LIMIT 3\G
*************************** 1. row ***************************
help_keyword_id: 0
name: JOIN
*************************** 2. row ***************************
help_keyword_id: 1
name: REPEAT
*************************** 3. row ***************************
help_keyword_id: 2
name: SERIALIZABLE
3 rows in set (0.00 sec)
My question asked out of pure curiosity: Is there any rationale behind choosing the character combination \G
?
Short Answer
The ubiquitous semicolon command terminator ;
is actually shorthand for the \g
command, which is in itself shorthand for the go
command. The go
command is used both historically and currently in other flavours of SQL to submit batches of commands to be compiled and / or interpretted by the server. The \G
command seems to inherit it's characteristic letter from \g
, and is capitalised to further indicate a modified behaviour, as described by...
mysql> help
...
\g go Send command to mysql server.
\G ego Send command to mysql server, display result vertically.
...
Longer Answer ( It should really be \E )
Entering help
at the mysql prompt lists all the possible mysql commands, including go
and ego
shown above. The ego
command acquires a prepended 'e' indicating that this form of the go
command also adopts a behaviour that would normally be imposed by invoking mysql with the similar switch mysql -E
From man mysql...
...
--vertical, -E
Print query output rows vertically (one line per column value).
Without this option, you can specify vertical output for individual
statements by terminating them with \G.
...
So why use -E
as shorthand for --vertical
?... Because both V
, v
, and e
had already been assigned as switches to other invocation behaviours. The ego
command could just have easily used \E
as it's shortcut, but confusingly adopted a capitalised version of the \g
command.
In summary...
--vertical >> -E >> ego >> \G ...Tada !