CODEWITHSUNDEEP
csvcassandracql
bhomass
bhomass

Reputation: 3572

use cql copy for map data

there is one post for copying multi-value data like list and set from csv to cassandra table,

Import CSV with multi-valued (collection) attributes to Cassandra

has any one done this for map type data?

Upvotes: 1

Views: 1596

Answers (1)

Aaron
Aaron

Reputation: 57748

Sure, I'll give you a simple example that uses both a map and a list. Consider the following table designed to hold starship data, as well as a list of crew and passengers:

CREATE TABLE shipregistry (
  name text,
  class text,
  hullnumber text,
  crew map<text,text>,
  passengers list<text>,
  PRIMARY KEY ((name))
);

I will load this table's data from the following text file (/home/aploetz/shipregistry_20150302.csv), which has a header and a single row of pipe-delimited data:

name|class|crew|hullnumber|passengers
Serenity|03-K64-Firefly|{'1st Officer': 'Zoey Washburne', 'captain': 'Malcolm Reynolds', 'engineer': 'Kaylee Frye', 'pilot': 'Hoban Washburne'}|G-82659|['Simon Tam', 'River Tam', 'Derial Book', 'Inara Serra']

I will then import it using the cqlsh COPY command:

aploetz@cqlsh:presentation> COPY shipregistry FROM
'/home/aploetz/shipregistry_20150302.csv' WITH HEADER=true and DELIMITER='|';

1 rows imported in 0.017 seconds.

Important to note, is that the list data for the passengers column, is comma-delimited and enclosed in brackets:

['Simon Tam', 'River Tam', 'Derial Book', 'Inara Serra']

Likewise, the map data for the crew column, is a comma-delimited list of key-value pairs and enclosed in braces:

{'1st Officer': 'Zoey Washburne', 'captain': 'Malcolm Reynolds', 'engineer': 'Kaylee Frye', 'pilot': 'Hoban Washburne'}

I chose a pipe as a delimiter to make this easier on myself and avoid potential clashes with commas in the collection types.

Upvotes: 5

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