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    <p><strong>- Where the activities of Customer are getting saved ?</strong></p> <p>They are not getting saved as "activities of customer" anywhere in the DB.When the activities of a customer are needed, they are loaded together with the customer using a join query on the <code>customer_id</code> column, or they are loaded later (lazy-loading) using a separate query that filters the <code>customer_id</code> column.</p> <p><strong>- How the update and delete operation of both of the entities will effect each other?</strong></p> <p>A delete of an activity will not affect the customer, but next time its activities are loaded, the deleted activity will not be part of the collection anymore.</p> <p>How the delete of a customer activities can be defined using the cascade attribute on the <code>@ManyToOne</code>, for example :</p> <p><code>@OneToMany(mappedBy = "customer", cascade = CascadeType.REMOVE)</code></p> <p>Basically, the desired behavior depends on if an activity can exist on its own without a customer : if yes, then the customer can be deleted, and the <code>customer_id</code> field can be set to null on the activity table. Otherwise the activities belonging to a customer will be 'cascade-deleted'. Or a customer just can0t be deleted before one has removed all its activities first.</p> <p><strong>- Is it the right way to create @OneToMany and @ManyToOne relationship?</strong></p> <p>Yes, it is correct.</p> <p><strong>- Can I add column name on activities?</strong></p> <p>No, it wouldn't make any sense. A column could only contain one ID, and activities is a collection.</p> <p>I hope this helps.</p>
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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