Map column

Write one or more values into a non-frozen map column. If a table specifies a map to hold data, then use INSERT or UPDATE to enter data.

A frozen map column can only insert or update the entire map, and elements cannot be prepended or appended to the map.

Prerequisites

  • Keyspace exists

  • Table exists

  • Map column exists

  • Set or replace map data, using the INSERT or UPDATE statement, and enclosing the integer and text values in a map collection with curly brackets, separated by a colon.

    INSERT INTO cycling.cyclist_teams (
      id, firstname, lastname, teams
    ) VALUES (
      5b6962dd-3f90-4c93-8f61-eabfa4a803e2, 
      'Marianne',
      'VOS', 
      {
        2015 : 'Rabobank-Liv Woman Cycling Team', 
        2014 : 'Rabobank-Liv Woman Cycling Team'
      }
    );

    Using INSERT in this manner will replace the entire map.

  • Use the UPDATE statement to insert values into the map. Append an element to the map by enclosing the key-value pair in curly brackets and using the addition (+) operator.

    UPDATE cycling.cyclist_teams
    SET teams = teams + { 2009 : 'DSB Bank - Nederland bloeit' }
    WHERE id = 5b6962dd-3f90-4c93-8f61-eabfa4a803e2;
  • Set a specific element using the UPDATE statement, enclosing the specific key of the element, an integer, in square brackets, and using the equals operator to map the value assigned to the key.

    UPDATE cycling.cyclist_teams
    SET teams[2006] = 'Team DSB - Ballast Nedam'
    WHERE id = 5b6962dd-3f90-4c93-8f61-eabfa4a803e2;
  • Delete an element from the map using the DELETE statement and enclosing the specific key of the element in square brackets:

    DELETE teams[2009] FROM cycling.cyclist_teams
      WHERE id=e7cd5752-bc0d-4157-a80f-7523add8dbcd;
  • Alternatively, remove all elements having a particular value using the UPDATE statement, the subtraction operator (-), and the map key values in curly brackets.

    UPDATE cycling.cyclist_teams
    SET teams = teams - { 2013, 2014 }
    WHERE id = e7cd5752-bc0d-4157-a80f-7523add8dbcd;

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