qhs 
SQL queries on CSV and TSV files
This is a Haskell implementation of q command.
Installation
Homebrew
$ brew install itchyny/tap/qhsBuild with stack
Prepare stack command from here.
$ git clone https://github.com/itchyny/qhs
$ cd qhs
$ stack install
$ export PATH=$PATH:$HOME/.local/bin
$ qhs "SELECT 100+200"
300Usage
In the beginning, qhs [QUERY] is the basic usage.
$ wc * > wc_out.txt
$ qhs "SELECT * FROM ./wc_out.txt"
66 471 3131 File.hs
118 649 4962 Main.hs
61 258 2346 Option.hs
51 366 2564 Parser.hs
45 273 1769 SQL.hs
341 2017 14772 totalYou can specify the file name for the table name.
The column names are automatically assigned as c1, c2 and so on.
$ qhs "SELECT c4,c1 FROM ./wc_out.txt WHERE c4 <> 'total' ORDER BY c1 DESC"
Main.hs 118
File.hs 66
Option.hs 61
Parser.hs 51
SQL.hs 45The qhs command can read the table from the standard input as well.
$ wc * | qhs "SELECT c4,c1 FROM - WHERE c4 <> 'total' ORDER BY c1 DESC"
Main.hs 118
File.hs 66
Option.hs 61
Parser.hs 51
SQL.hs 45You can use -H flag to make qhs regard the head line as the row of column names.
$ cat basic.csv
foo,bar,baz
a0,1,a2
b0,3,b2
c0,,c2
$ qhs -H "SELECT * FROM basic.csv WHERE bar IS NOT NULL"
a0 1 a2
b0 3 b2You can use the basic SQL operations; GROUP BY, ORDER BY, LIMIT and COUNT(*).
$ ps -ef | qhs -H -O "SELECT UID,COUNT(*) cnt FROM - GROUP BY UID ORDER BY cnt DESC LIMIT 3"
UID cnt
503 102
0 86
89 3You can also use other SQL operations like JOIN, UNION and sub-query.
The command helps you deal with multiple CSV files.
Please refer to qhs --help for further options.
The command respects the behaviour of the original q command.
$ qhs --help
qhs - SQL queries on CSV and TSV files
Usage: qhs [-H|--skip-header] [-O|--output-header] [-d|--delimiter DELIMITER]
[-t|--tab-delimited] [-D|--output-delimiter OUTPUT_DELIMITER]
[-T|--tab-delimited-output] [-k|--keep-leading-whitespace]
[-z|--gzipped] [-q|--query-filename QUERY_FILENAME] [QUERY]
Available options:
-h,--help Show this help text
-v,--version Show the version of the command.
-H,--skip-header Skip the header row for row input and use it for
column names instead.
-O,--output-header Output the header line.
-d,--delimiter DELIMITER Field delimiter. If not specified, automatically
detected.
-t,--tab-delimited Same as -d $'\t'.
-D,--output-delimiter OUTPUT_DELIMITER
Field delimiter for output. If not specified, the
argument of -d DELIMITER is used.
-T,--tab-delimited-output
Same as -D $'\t'.
-k,--keep-leading-whitespace
Keep leading whitespace in values. The leading
whitespaces are stripped off by default.
-z,--gzipped Assuming the gzipped input.
-q,--query-filename QUERY_FILENAME
Read query from the provided filename.Author
itchyny (https://github.com/itchyny)
License
This software is released under the MIT License, see LICENSE.