Updating a List in Cassandra
Last Updated :
12 Dec, 2019
In Cassandra list is a Collection Data Type. In this article, we will discuss how we can update a list in different ways such that we can add elements in the list at any position where we want. we can also append a list.
Let’s discuss one by one.
Consider cluster1 is a keyspace.
CREATE KEYSPACE cluster1
WITH replication = {'class': 'SimpleStrategy',
'replication_factor' : 1};
Now, here we are going to create a table first. let’s have a look.
Create Table Food_App
(
Cafe_id Int Primary Key,
Order_Date Date,
Order_status Text,
Cafe_items list<text>
);
Now, we are going to insert some data into the Food_App table.
Let’s have a look.
INSERT INTO Food_App (Cafe_id, Order_Date, Order_status, Cafe_items)
VALUES (8045, '2019-02-13', 'Available', {'Banana', 'Mango', 'Apple'});
INSERT INTO Food_App (Cafe_id, Order_Date, Order_status, Cafe_items)
VALUES (8046, '2019-02-15', 'Not Available', {'guava', 'juice', 'milk'});
INSERT INTO Food_App (Cafe_id, Order_Date, Order_status, Cafe_items)
VALUES (8047, '2019-02-18', 'Available', {'grapes', 'papaya', 'mix fruit'});
Now, let’s see the output.
select *
from Food_App;
Output:
Updating a list:
UPDATE Food_App
SET Cafe_items = ['fruits', 'lemon tea', 'green tea']
Where Cafe_id = 8045;
Now, let’s see the output.
select *
from Food_App;
Output:
To append an element to the list, switch the order of the new element data and the list name:
UPDATE Food_App
SET Cafe_items = Cafe_items + ['bread']
WHERE Cafe_id = 8045;
Now, let’s see the output.
select *
from Food_App;
Output:
To prepend an element to the list, enclose it in square brackets and use the addition (+) operator:
UPDATE Food_App
SET Cafe_items = ['bread']+Cafe_items
WHERE Cafe_id = 8046;
Now, let’s see the output.
select *
from Food_App;
Output:
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