title: How to write a SQL query to get sum of transactions?
body: <p>I want sql query for this . I have three tables customer,account, transaction
  the schema of the are as below<a href="https://i.stack.imgur.com/OXUCr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OXUCr.png" alt="enter image description here" /></a></p>
  <p>I want to get customer details, account id, sum of transaction id<a href="https://i.stack.imgur.com/ct6DF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ct6DF.png" alt="enter image description here" /></a></p>