Make an existing nullable column non nullable

i have an existing column which ive created, The column has some data in it. How do i make it non nullable, still preserving the data.

 .table('users', function(table){
    table.string('mobile').notNull();
  })

This attempts to add a new column.

[et]

For those of you coming here from google, the syntax is:

Converting an existing nonNullable column to be nullable (reverse the up/down if you want a nonNullable to be nullable).

exports.up = knex => {
  return knex.schema
    .alterTable('images', (table) => {
      table.string('checksum').nullable().alter();
    });
};

exports.down = knex => {
  return knex.schema
    .alterTable('images', table => {
      table.string('checksum').notNullable().alter();
    });
};

[marcel099]

For those of you coming here from google, the syntax is:

Converting an existing nonNullable column to be nullable (reverse the up/down if you want a nonNullable to be nullable).

exports.up = knex => {
  return knex.schema
    .alterTable('images', (table) => {
      table.string('checksum').nullable().alter();
    });
};

exports.down = knex => {
  return knex.schema
    .alterTable('images', table => {
      table.string('checksum').notNullable().alter();
    });
};

It’s worth mentioning that the .nullable().alter() methods didn’t work for me because my personal project uses SQLIte and it does not support alter column.

Here’s de error message:

migration file "05_alter_users_drop_nullability_of_avatar.ts" failed
migration failed with error: Sqlite does not support alter column.