Clickhouse bar() function

Plotting simple bar charts in Clickhouse

I have discovered great bar() Clickhouse function recently. This allows plotting simple charts right inside your terminal to get quick overview of data.

So the function is pretty simple:

SELECT bar(10, 0, 15, 20);
┌─bar(10, 0, 15, 20)─┐
│ █████████████▎     │
└────────────────────┘

In this example we draw bar which is of size 10 out of 15 (max), with physical width of 20:

This cool function can be used to automaticlly plot bars inside SELECT queries:

WITH ( SELECT max(value) FROM data WHERE (entity_id = 34)
       AND (property = 'usd') AND empty(object)
       AND (year(at) = 2021) )
AS max_value
SELECT date(at), value, bar(value, 0, max_value, 30)
FROM data
WHERE (entity_id = 34) AND (property = 'usd') AND empty(object) AND (year(at) = 2021);
┌───DATE(at)─┬───────value─┬─bar(value, 0, max_value, 30)───┐
│ 2021-02-01 │  2966188533 │ ██████▊                        │
│ 2021-03-01 │  4267240303 │ █████████▊                     │
│ 2021-09-01 │  4428807027 │ ██████████▎                    │
│ 2021-08-01 │  4463003564 │ ██████████▍                    │
│ 2021-05-01 │  4959032942 │ ███████████▌                   │
│ 2021-11-01 │  5059683648 │ ███████████▋                   │
│ 2021-04-01 │  5069026304 │ ███████████▋                   │
│ 2021-06-01 │  5378356519 │ ████████████▌                  │
│ 2021-07-01 │  5575512564 │ █████████████                  │
│ 2021-10-01 │  5924804713 │ █████████████▋                 │
│ 2021-12-01 │  6675097986 │ ███████████████▌               │
│ 2021-12-31 │ 12833813608 │ ██████████████████████████████ │
└────────────┴─────────────┴────────────────────────────────┘

Here we first use WITH statement to fetch max value for the given filters. You can skip this if you understand what are min/max values for your future query. Then we use bar() function with value column from query and max_value variable to plot beautiful bars.