How to perform CRUD opearation on Cassandra using CQLSH

This article will show the useful commands to perform CRUD operation on Cassandra using CQLSH. 1) Insert the data Syntax is: insert into <TABLE_NAME>(COLUMN1, COLUMN2) values (VALUES1, VALUES2); The table structure to insert the data is: CREATE TABLE cassandrademo.users ( user_id int PRIMARY KEY, user_email text, user_name text, user_pwd text ) Use the following command […]

How to truncate a table in Cassandra using CQLSH

Syntax for truncating a table/columnfamily is : TRUNCATE <TABLE_NAME | COLUMN_FAMILY_NAME> Using this command will delete all the rows from the table/columnfamily. Let’s say the data in our table is: select * from users; Output: user_id | user_email | user_name | user_pwd ———+————–+———–+———- 1 | aa@gmail.com | user1 | pwd1 To truncate all the data […]

How to alter a table in Cassandra using CQLSH

Syntax for altering table/columnfamily is: ALTER TABLE <TABLENAME> <OPEARTION> or ALTER COLUMNFAMILY <TABLENAME> <OPEARTION> Below example is given for adding a column in the table. alter table cassandrademo.users add user_phone text; Verify the table structure by using: describe table users; Output: CREATE TABLE cassandrademo.users ( user_id int PRIMARY KEY, user_email text, user_name text, user_phone text, […]

How to create Columnfamilies or Tables in Cassandra using cqlsh

Syntax for creating a table/columnfamily is: CREATE TABLE <TABLE_NAME> ( ‘column-definition’, ‘column-definition’, ) (WITH <OPTION> AND <OPTION>) or CREATE COLUMNFAMILY <TABLE_NAME> ( ‘column-definition’, ‘column-definition’, ) (WITH <OPTION> AND <OPTION>) Syntax for defining a column in the table is: column_name column_data_type Example to create a table is given below: create table cassandrademo.users( user_id int Primary Key, […]

How to create Keyspace in Cassandra

In this example I am referring Cassandra 2.1.5 version Creating a keyspace Use the following to create a keyspace create keyspace cassand with replication={‘class’:’SimpleStrategy’, ‘replication_factor’:3} and durable_writes=true Here class attributes indicates the replication strategy. 3 types are strategies are applicable: Simple Strategy – Provides simple replication for the cluster. Network Topology Strategy – Each data-center […]

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How to install DataStax DevCenter on MacOS for Cassandra

1) Go the dowload page of DataStax http://www.datastax.com/download 2) Go bottom down the page and select DEVCENTER Visual Query Tool. 3) Select 64 bit for MacOS. It will start downloading. 4) Extract the file contents tar -xzvf Documents/DevCenter-1.3.1-macosx-x86_64.tar.gz 5) Go to the extracted folder and click on DevCenter icon to launch. 6) The DevCenter window […]