Inserting data#

The dclient insert command can be used to insert data from a local file directly into a Datasette instance, via the Write API introduced in the Datasette 1.0 alphas.

First you’ll need to authenticate with the instance.

To insert data from a data.csv file into a table called my_table, creating that table if it does not exist:

dclient insert \ \
  my_table data.csv --create

You can also pipe data into standard input:

curl -s '' | \
  dclient insert \ \
    issues - --create

Streaming data#

dclient insert works for streaming data as well.

If you have a log file containing newline-delimited JSON you can tail it and send it to a Datasette instance like this:

tail -f log.jsonl | \
  dclient insert logs - --nl

When reading from standard input (filename -) you are required to specify the format. In this example that’s --nl for newline-delimited JSON. --csv and --tsv are supported for streaming as well, but --json is not.

In streaming mode records default to being sent to the server every 100 records or every 10 seconds, whichever comes first. You can adjust these values using the --batch-size and --interval settings. For example, here’s how to send every 10 records or if 5 seconds has passed since the last time data was sent to the server:

tail -f log.jsonl | dclient insert \ logs - --nl --create \
  --batch-size 10 \
  --interval 5

Supported formats#

Data can be inserted from CSV, TSV, JSON or newline-delimited JSON files.

The format of the file will be automatically detected. You can override this by using one of the following options:

  • --csv

  • --tsv

  • --json

  • --nl for newline-delimited JSON

Use --encoding <encoding> to specify the encoding of the file. The default is utf-8.


JSON files should be formatted like this:

        "id": 1
        "column1": "value1",
        "column2": "value2"
        "id": 2
        "column1": "value1",
        "column2": "value2"

Newline-delimited files like this:

{"id": 1, "column1": "value1", "column2": "value2"}
{"id": 2, "column1": "value1", "column2": "value2"}

CSV and TSV#

CSV and TSV files should have a header row containing the names of the columns.

By default, dclient will attempt to detect the types of the different columns in the CSV and TSV files - so if a column only ever contains numeric integers it will be stored as integers in the SQLite database.

You can disable this and have every value treated as a string using --no-detect-types.

Other options#

  • --create - create the table if it doesn’t already exist

  • --replace - replace any rows with a matching primary key

  • --ignore - ignore any rows with a matching existing primary key

  • --alter - alter table to add any columns that are missing

  • --pk id - set a primary key (for if the table is being created)

If you use --create a table will be created with rows to match the columns in your uploaded data - using the correctly detected types, unless you use --no-detect-types in which case every column will be of type text.

dclient insert –help#


  Insert data into a remote Datasette instance

  Example usage:

      dclient insert \ \
        mytable data.csv --pk id --create

  --csv                 Input is CSV
  --tsv                 Input is TSV
  --json                Input is JSON
  --nl                  Input is newline-delimited JSON
  --encoding TEXT       Character encoding for CSV/TSV
  --no-detect-types     Don't detect column types for CSV/TSV
  --replace             Replace rows with a matching primary key
  --ignore              Ignore rows with a matching primary key
  --create              Create table if it does not exist
  --alter               Alter table to add any missing columns
  --pk TEXT             Columns to use as the primary key when creating the
  --batch-size INTEGER  Send rows in batches of this size
  --interval FLOAT      Send batch at least every X seconds
  -t, --token TEXT      API token
  --silent              Don't output progress
  -v, --verbose         Verbose output: show HTTP request and response
  --help                Show this message and exit.