NAME
SQL::Steno - Short hand for SQL and compact output
SYNOPSIS
Type some short-hand, see the corresponding SQL and its output:
steno> TABLE1;somecolumn > 2 -- ; after tables means where
select * from TABLE1 where somecolumn > 2;
prepare: 0.000s execute: 0.073s rows: 14
id|column1 |column2
| | |column3
| | | |somecolumn
----|-------------------------------------------|----|-|-|
27|foo | |a|7|
49|bar |abcd|a|3|
81|baz\nbazinga\nbazurka |jk |b|9|
1984|bla bla bla bla bla bla bla bla bla bla bla|xyz |c|5|
...
steno> /abc|foo/#TBL1;.socol > 2 -- /regexp/ grep, #tableabbrev, .columnabbrev
select * from TABLE1 where somecolumn > 2;
prepare: 0.000s execute: 0.039s rows: 14
id|column1
| |column2
| | |[column3=a]
| | |somecolumn
--|---|----|-|
27|foo| |7|
49|bar|abcd|3|
steno> .c1,.c2,.some;#TE1#:ob2d3 -- ; before tables means from, 2nd # alias, :macro
select column1,column2,somecolumn from TABLE1 TE1 order by 2 desc, 3;
...
steno> n(), yr(), cw(,1,2,3) -- functionabbrev before (, can have initial default arg
select count(*), year(now()), concat_ws(',',1,2,3);
...
steno> .col1,.clm2,.sn;#TBL1:jTBL2 u(id);mydate :b :m+3d and :d-w -- :jTABLEABBREV and :+/- family
select column1,column2,somecolumn from TABLE1 join TABLE2 using(id) where mydate between date_format(now(),"%Y-%m-01")+interval 3 day and curdate()-interval 1 week;
...
DESCRIPTION
You're the command-line type, but are tired of typing "select * from
TABLE where CONDITION", always forgetting the final ";"? Output always
seems far too wide and at least mysql cli messes up the format when it
includes newlines?
This module consists of the function "convert" which implements a
configurable ultra-compact language that maps to SQL. Then there is
"run" which performs normal SQL queries but has various tricks for
narrowing the output. It can also grep on whole rows, rather than having
to list all fields that you expect to match. They get combined by the
function "shell" which converts and runs in an endless loop.
This is work in progress, only recently isolated from a monolithic
script. Language elements and API may change as the need arises, e.g.
":macro" used to be @macro, till the day I wanted to use an SQL-variable
and noticed the collision. In this early stage, you are more than
welcome to propose ammendments, especially if they make the language
more powerful and/or more consistent. Defaults are for MariaDB/MySQL,
though the mechanism also works with other DBs.
convert
This function takes a short-hand query in $_ and transforms it to SQL.
See "shell" for more run time oriented features.
First it looks for ":macro". These are mostly simple text-replacements
stored in %Macros. There are also some dynamic macros. Those starting
with ":j" (join) or ":lj" (left join) may continue into a table spec
without the leading "#". E.g. ":ljtbl#t" might expand to "left join
table t".
Those starting with ":gb" (group by) or ":ob" (order by) may be followed
by result columns numbers from 1-9, each optionally followed by a or d
for asc or desc. Macros can also be ":{Perl code}", which gets replaced
by what it returns.
Then there are the time macros, where an optional leading letter
indicates a base time, and an optional trailing letter with an optional
count means the offset. The letters are:
y (this) year. E.g. ":y+2m" is march this year.
q (this) quarter. E.g. ":q+0" is this quarter, ":q+q" is next quarter.
m (this) month. E.g. ":-3m" is whatever precedes, minus 3 months.
w (this) week (starting on $weekstart). E.g. ":w+3d" is this week
thursday (or wednesday).
d (this) day. E.g. ":d-w" is midnight one week ago.
h (this) hour. E.g. ":h+30M" is half past current hour.
M (this) minute. E.g. ":+10M" is whatever precedes, plus 10min.
s (this) second. E.g. ":s-2h" is exactly 2h ago.
Then it looks for "#tbl", "#tbl#" or "#tbl#alias". Here tbl is a key of
%Tables or any abbreviation of known tables in @Tables. If followed by
"#", the abbreviation is used as an alias, unless an alias directly
follows, in which case that is used.
Then it looks for ".col", ".col." ".col.alias". Here col is a key of
%Columns or any abbreviation of columns of any table recognized in the
query. If followed by ".", the abbreviation is used as an alias, unless
an alias directly follows, in which case that is used. It tries to be
clever about whether the 1st "." needs to be preserved, i.e. following a
table name.
Finally it looks for "func(". Here func is a key of %Functions or any
abbreviation of known functions in @Functions, which includes words
typically followed by an opening parenthesis, such as "u(" for "using(".
"i(" is "in(", so that "in(" is free for matching "ifnull(", but more
importantly, because it has a smart brother: "I(" is also "in(", where
quoting is applied as necessary, and unless you give an initial comma
"I(,", the elements are separated on space. E.g. "I(a 3 a's q"q)" and
"I(,a,3,a's,q"q)" both give "in("a",3,"a's",'q"q')". If the 1st argument
of a function is empty and the abbrev or function is found in
%DefaultArguments the value becomes the 1st argument.
Finally it picks on the structure of the statement: These keywords can
be abbreviated: "se(lect)", "ins(ert)", "upd(ate)" or "del(ete)". If
none of these or "set" is present, "select" is assumed as default (more
keywords need to be recognized in the future).
For "select", semicolons are alternately replaced by "from" (the 1st
being optional if it starts with a table name) and "where". If no result
columns are given, they default to "*", see "SYNOPSIS". For "update",
semicolons are frst replaced by "set" and then "where".
shell
This function reads, converts and (if $dbh is set) runs in an end-less
loop (i.e. till end of file or "^D"). Reading is a single line affair,
unless you request otherwise. This can happen either, as in Unix Shell,
by using continuation lines as long as you put a backslash at the end of
your lines. Or there is a special case, if the 1st line starts with
"\\", then everything up to "\\" at the end of one of the next lines,
constitutes one entry.
In addition to converting it offers a few extra features, performed in
this order (i.e. &xyz can return "/regexp/=literal sql" etc.):
&query arg, ...
&query( arg, ... ) following text
&{Perl code} following text
These allow canned entries and are more complex than macros, in that
they take arguments and replacement can depend on the argument.
Run *Perl code*. It sees the *following text* in $_ and may modify
it. If it returns undef this statement is skipped. If it returns a
DBI statement handle run that instead of this statement. Else
replace with what it returns.
Reprocess result as a shell entry (i.e. it may return another
"&"query).
{Perl code}statement
Call *Perl code* for every output row returned by the *statement*
with the array of values as first and the array of column names as
second argument. It may modify individual values, but not the array.
If it returns false, the row is skipped.
/regexp/statement
This will treat the *statement* normally, but will join each output
row with '|' characters (which need to be matched as "\/") and check
that against the regexp. Only matching rows are considered. You may
combine "{Perl code}/regexp/".
=literal sql
A preceding "=" prevents conversion, useful for hitherto untreated
keywords or where the conversion doesn't play well with your
intention.
? Help prefix. Alone it will give an overview. You can follow up with
any of the special syntaxes, with or without an abbreviation. E.g.
"?(" will show all function abbreviations, whereas "?abbrev(" will
show only those functions matching abbrev or "?#abbrev" only those
tables matching abbrev.
??statemment
Will convert and show, but not perform statement. If $dbh is not
set, this is the default behaviour.
!System Shell code
Run it.
>filename
>>filename
Redirect or append next statement's output to *filename*. If it has
a suffix ".csv", ".yaml" or ".yml", an according format is used.
|System Shell code
Pipe next statement's output through *System Shell code*.
YOUR SCRIPT
package SQL::Steno; # doesn't export yet, so get the functions easily
use SQL::Steno;
use DBI;
our $dbh = DBI->connect( ... ); # preferably mysql, but other DBs should work (with limitations).
# If you want #tbl and .col to work, (only) one of:
init_from_query; # fast, defaults to mysql information_schema, for which you need read permission
init; # slow, using DBI dbh methods.
# Set any of the variables mentioned above to get you favourite abbreviations.
shell;
LICENSE
This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
DBI, SQL::Interp, SQL::Preproc, SQL::Yapp, Jade
AUTHOR
(C) 2015 by Daniel Pfeiffer .