Migrations for schema changes in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the migration tool in an Express project.

Express

const migrate = require('[1]');

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Apg

Bexpress

Csequelize-cli

Dmigrate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of the migration tool.

Using 'pg' which is for PostgreSQL client, not migrations.

The migration tool is usually imported with the name 'migrate' or similar. Here, 'migrate' is the correct module to require for schema migrations.

2fill in blank

medium

Complete the code to define a migration that creates a 'users' table.

Express

exports.up = function(knex) {
  return knex.schema.createTable('[1]', function(table) {
    table.increments('id').primary();
    table.string('name');
  });
};

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Ausers

Baccounts

Cprofiles

Dcustomers

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong table name like 'accounts' or 'customers'.

The migration creates a table named 'users'. So the table name must be 'users'.

3fill in blank

hard

Fix the error in the migration rollback function to drop the 'users' table.

Express

exports.down = function(knex) {
  return knex.schema.[1]('users');
};

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AdropTable

BdestroyTable

CdeleteTable

DremoveTable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'removeTable' or 'deleteTable' which do not exist in Knex.

The correct method to drop a table in Knex migrations is 'dropTable'.

4fill in blank

hard

Fill both blanks to add a new column 'email' of type string to the 'users' table.

Express

exports.up = function(knex) {
  return knex.schema.table('users', function(table) {
    table.[1]('[2]');
  });
};

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Astring

Bemail

Cinteger

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'integer' instead of 'string' for the email column.

Using 'name' instead of 'email' as the column name.

To add a string column named 'email', use table.string('email').

5fill in blank

hard

Fill all three blanks to rename the column 'username' to 'user_name' in the 'users' table.

Express

exports.up = function(knex) {
  return knex.schema.table('[1]', function(table) {
    table.renameColumn('[2]', '[3]');
  });
};

Drag options to blanks, or click blank then click option'

Ausers

Busername

Cuser_name

Daccounts

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table name like 'accounts'.

Swapping old and new column names.

The table is 'users'. The old column is 'username'. The new column is 'user_name'.