# Writing data to Database | Remix Supabase SaaS Kit

> Learn how to write, update and delete data using the Supabase Database in Remix Supabase SaaS Kit project.

*Canonical: https://makerkit.dev/docs/remix-supabase/data-fetching/writing-data-to-supabase*

---

Similarly to reading data, we may want to create a `custom
hook` also when we write, update or delete data to our Supabase database.

Assuming we have an entity called `tasks`, and we want to create a hook to
create a new `Task`, we can do the following.

1. First, we create a new hook at `lib/tasks/hooks/use-create-task.ts`
2. We add the `tasks` table name to `lib/db-tables.ts`
3. We create a `mutations.ts` file within `lib/tasks`

```ts
export const TASKS_TABLE = `tasks`;
```

In our mutations file, we will add all the mutations we want to perform on
the `tasks` table. In this case, we will add a `createTask` mutation.

```ts
export function createTask(
  client: Client,
  task: Task,
) {
  return client.from(TASKS_TABLE).insert(task).throwOnError();
}
````

Now, we can use the `createTask` mutation in our `useCreateTask` hook.

We will be using the `useMutation` hook from `react-query` to create our hook.

 ```tsx {% title="lib/tasks/hooks/use-create-task.ts" %}
function useCreateTaskMutation(task: Task) {
  const client = useSupabase();

  return useMutation(
    async (task: Task) => {
      return createTask(client, task);
    }
  );
}

export default useCreateTaskMutation;
```

Let's take a look at a complete example of a form that makes a request using
the hook above:

 ```tsx {% title="components/tasks/CreateTaskForm.tsx" %}
import { useNavigate } from '@remix-run/react';
import type { FormEventHandler } from 'react';
import { useCallback } from 'react';
import { toast } from 'sonner';

import TextField from '~/core/ui/TextField';
import Button from '~/core/ui/Button';
import useCreateTaskMutation from '~/lib/tasks/hooks/use-create-task';

import useCurrentOrganization from '~/lib/organizations/hooks/use-current-organization';

const CreateTaskForm = () => {
  const createTaskMutation = useCreateTaskMutation();
  const navigate = useNavigate();
  const organization = useCurrentOrganization();
  const organizationId = organization?.id as number;

  const onCreateTask: FormEventHandler<HTMLFormElement> = useCallback(
    async (event) => {
      event.preventDefault();

      const target = event.currentTarget;
      const data = new FormData(target);
      const name = data.get('name') as string;
      const dueDate = (data.get('dueDate') as string) || getDefaultDueDate();

      if (name.trim().length < 3) {
        toast.error('Task name must be at least 3 characters long');

        return;
      }

      const task = {
        organizationId,
        name,
        dueDate,
        done: false,
      };

      // create task
      await createTaskMutation.mutateAsync(task);

      // redirect to /tasks
      return navigate(`/tasks`);
    },
    [navigate, createTaskMutation, organizationId]
  );

  return (
    <form onSubmit={onCreateTask}>
      <div>
        <TextField.Label>
          Name
          <TextField.Input
            required
            name={'name'}
            placeholder={'ex. Launch on IndieHackers'}
          />
          <TextField.Hint>Hint: whatever you do, ship!</TextField.Hint>
        </TextField.Label>

        <TextField.Label>
          Due date
          <TextField.Input name={'dueDate'} type={'date'} />
        </TextField.Label>

        <div>
          <Button>Create Task</Button>
        </div>
      </div>
    </form>
  );
};

export default CreateTaskForm;

function getDefaultDueDate() {
  const date = new Date();
  date.setDate(date.getDate() + 1);
  date.setHours(23, 59, 59);

  return date.toDateString();
}
```