Create KeySpace and Table

To create a keyspace and table in Apache Cassandra, you can use the Cassandra Query Language (CQL). Below are the steps to create a keyspace and table:

1. Start cqlsh:

Open a command prompt or terminal window and start the cqlsh command-line tool. This tool allows you to interact with the Cassandra cluster using CQL.

cqlsh

2. Create a Keyspace:

Use the CREATE KEYSPACE statement to create a keyspace. Keyspaces are the top-level containers for tables in Cassandra.

CREATE KEYSPACE IF NOT EXISTS my_keyspace 
WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};

This statement creates a keyspace named my_keyspace with a replication strategy of SimpleStrategy and a replication factor of 1. Adjust the replication strategy and replication factor based on your requirements.

3. Use the Keyspace:

After creating the keyspace, use the USE statement to switch to the newly created keyspace.

USE my_keyspace;

4. Create a Table:

Now, you can create a table within the keyspace using the CREATE TABLE statement.

CREATE TABLE IF NOT EXISTS users (
    user_id UUID PRIMARY KEY,
    name TEXT,
    email TEXT
);

This statement creates a table named users with columns user_id, name, and email. The user_id column is designated as the primary key.

5. Verify:

You can verify that the keyspace and table are created successfully by describing them using the DESCRIBE command:

DESCRIBE KEYSPACES;
DESCRIBE TABLES;

These commands will display the list of keyspaces and tables in the Cassandra cluster.

6. Insert Data (Optional):

If desired, you can insert data into the newly created table using the INSERT statement:

INSERT INTO users (user_id, name, email) VALUES (uuid(), 'John Doe', 'john@example.com');

Replace the values with your own data.

7. Query Data (Optional):

You can query the data from the table using the SELECT statement:

SELECT * FROM users;

This will retrieve all rows from the users table.

8. Exit cqlsh:

To exit the cqlsh shell, simply type exit or press Ctrl + D.

exit

That's it! You have successfully created a keyspace and table in Apache Cassandra and performed basic operations. Adjust the keyspace, table schema, and data as needed for your application requirements.