Node.js Database Integration 3

Question 1

In Prisma, what command regenerates the Prisma Client after modifying `schema.prisma`?

Accepted Answer

prisma generate

Answer

`prisma generate` reads the schema and regenerates the type-safe Prisma Client code.

Question 2

What is the correct way to handle transactions in node-postgres (`pg`) using a client from a pool?

Accepted Answer

Acquire a client, run BEGIN/COMMIT/ROLLBACK manually, then release

Answer

Transactions require a dedicated client; you issue BEGIN, run queries, then COMMIT or ROLLBACK, and always release the client.

Question 3

In Sequelize, what does `sync({ force: true })` do?

Accepted Answer

Drops and recreates all tables, destroying existing data

Answer

`force: true` drops all tables and recreates them, wiping all data — dangerous in production.

Question 4

Which MongoDB aggregation stage is used to filter documents, similar to a WHERE clause?

Accepted Answer

$match

Answer

`$match` filters the document stream to pass only documents that match the specified condition.

Question 5

What does the `N+1 query problem` refer to in the context of ORMs?

Accepted Answer

Executing one query to fetch N records, then N additional queries for related data

Answer

N+1 occurs when you fetch N parent records and then issue one extra query per record to load its relations, totaling N+1 queries.

Node.js Practice Test