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@beccam
Last active May 31, 2019 11:13
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Demo CRUD application with Node.js
const cassandra = require('cassandra-driver');
// TO DO: Fill in your own host and data center
const client = new cassandra.Client({
contactPoints: ['127.0.0.1'],
localDataCenter: 'datacenter1',
keyspace: 'demo'
});
function insertUser(lastname, age, city, email, firstname) {
// TO DO: execute a prepared statement that inserts one user into the table
const insert = 'INSERT INTO users (lastname, age, city, email, firstname) VALUES (?,?,?,?,?)';
const params = [ lastname, age, city, email, firstname ];
return client.execute(insert, params, { prepare : true });
}
function selectUser(lastname) {
// TO DO: execute a prepared that retrieves one user from the table
const select = 'SELECT firstname, age FROM users WHERE lastname = ?';
const params = [ lastname ] ;
return client.execute(select, params, { prepare : true });
}
function updateUser(age, lastname) {
// TO DO: execute a prepared statement that updates the age of one user
const update = 'UPDATE users SET age = ? WHERE lastname = ?';
return client.execute(update, [ age, lastname ], { prepare : true } )
}
function deleteUser(lastname) {
// TO DO: execute a prepared that deletes one user from the table
const remove = 'DELETE FROM users WHERE lastname = ?';
const params = [ lastname ];
return client.execute(remove, params, { prepare: true })
}
async function example() {
await client.connect();
await insertUser('Jones', 35, 'Austin', 'bob@example.com', 'Bob');
const rs1 = await selectUser('Jones');
const user1 = rs1.first();
if (user1) {
console.log("name = %s, age = %d", user1.firstname, user1.age);
} else {
console.log("No results");
}
await updateUser(36, 'Jones');
const rs2 = await selectUser('Jones');
const user2 = rs2.first();
if (user2) {
console.log("name = %s, age = %d", user2.firstname, user2.age);
} else {
console.log("No results");
}
await deleteUser('Jones');
await client.shutdown();
}
example();
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