sqlite3 one-liner(ish) for benchmarking

[simonw]

Follows #69 - the README at https://github.com/multiprocessio/dsq/tree/b7af2679038f8b09802c88f2f088bcc78fa8872c#benchmark says sqlite3 can't do one-liners, but it sort-of-can - this works for running the taxi query:

sqlite3 :memory: <<EOS
.mode csv
.import taxi.csv taxi
SELECT passenger_count, COUNT(*), AVG(total_amount) FROM taxi GROUP BY passenger_count
EOS

[simonw]

On my MacBook Pro (2.6Ghz 32MB 2019) it takes 12.4s using time, I've not tried with a proper benchmark.

[eatonphil]

Yeah I just am not considering that a reasonable one-liner. Open to other wording but the popularity of all these tools kind of demonstrates how that is not what everyone is settling for.

[simonw]

This works too:

sqlite3 :memory: -cmd '.mode csv' -cmd '.import taxi.csv taxi' 'SELECT passenger_count, COUNT(*), AVG(total_amount) FROM taxi GROUP BY passenger_count'

[eatonphil]

That's a good one! And wow it's 4s on my machine. Adding to the list.

[eatonphil]

Closed in 8f68cde

[simonw]

Turned this into a TIL: https://til.simonwillison.net/sqlite/one-line-csv-operations - I just found out you can output in different formats too, e.g.:

sqlite3 :memory: -cmd '.mode csv' -cmd '.import taxi.csv taxi' -cmd '.mode markdown' \
    'SELECT passenger_count, COUNT(*), AVG(total_amount) FROM taxi GROUP BY passenger_count'

Which outputs markdown you can embed in an issue like this:

passenger_count	COUNT(*)	AVG(total_amount)
	128020	32.2371511482553
0	42228	17.0214016766151
1	1533197	17.6418833067999
2	286461	18.0975870711456
3	72852	17.9153958710923
4	25510	18.452774990196
5	50291	17.2709248175672
6	32623	17.6002964166367
7	2	87.17
8	2	95.705
9	1	113.6

[jakiestfu]

Really slick, @simonw

[ryenus]

Meanwhile I have this cq bash function for interactive use:

# Query a csv file with sqlite
# Usage: cq <csv_file> [<table>]
cq() {
  local csv_file="${1:?Usage: cq <csv_file> [<table>]}" table="${2:-T}"
  sqlite3 -interactive -cmd '.headers on' -cmd '.prompt "\nsqlite> "' \
    -cmd '.mode csv' -cmd ".import '$csv_file' '$table'" -cmd ".mode column"
}