To query for entries with columns that are not null with JavaScript Sequelize, we use the Op.ne property.

For instance, we write

Post.update(
  {
    updatedAt: null,
  },
  {
    where: {
      deletedAt: {
        [Op.ne]: null,
      },
    },
  }
);

to select the entries that have the deletedAt field set to a non-null value with Op.ne.

And then we call update with an object to set updatedAt to null for entries that match the condition.