How do you implement optimistic locking with TypeORM to prevent lost updates in NestJS?

Q: How do you implement optimistic locking with TypeORM to prevent lost updates in NestJS?

// Entity — @VersionColumn auto-increments on every save @Entity() export class Product { @PrimaryGeneratedColumn() id: number; @Column() name: string; @Column() stock: number; @VersionColumn() // TypeORM manages this — do not set manually version: number; } // Service — client must send version back with the update async updateStock( id: number, newStock: number, version: number, ): Promise { return this.dataSource.transaction(async manager => { // TypeORM throws OptimisticLockVersionMismatchError if versions differ return manager.save(Product, { id, stock: newStock, version }); }); } // QueryBuilder approach — check version in WHERE clause await this.dataSource .createQueryBuilder() .update(Product) .set({ stock: newStock }) .where('id = :id AND version = :version', { id, version }) .execute() .then(result => { if (result.affected === 0) throw new ConflictException('Product was modified by another request'); }); @VersionColumn() stores an integer that TypeORM increments on every save automatically. If the incoming version does not match the DB version, TypeORM throws OptimisticLockVersionMismatchError. Map OptimisticLockVersionMismatchError to ConflictException (409) in a global exception filter. The client must send the version back with every update request — include it in the DTO. Optimistic locking is best for low-contention scenarios; use pessimistic locking for high-contention fields.

Difficulty: 6/10

optimistic locking, TypeORM, NestJS

Add @VersionColumn() to the entity — TypeORM auto-increments it on every save. If the version in the incoming update does not match the database version, TypeORM throws OptimisticLockVersionMismatchError. The QueryBuilder approach checks version in the WHERE clause and inspects affected rows to detect conflicts.

Optimistic locking with @VersionColumn

Optimistic locking implementation notes:

1
@VersionColumn() stores an integer that TypeORM increments on every save automatically.
2

How do you implement optimistic locking with TypeORM to prevent lost updates in NestJS?

Difficulty: 6/10

optimistic locking, TypeORM, NestJS

Add @VersionColumn() to the entity — TypeORM auto-increments it on every save. If the version in the incoming update does not match the database version, TypeORM throws OptimisticLockVersionMismatchError. The QueryBuilder approach checks version in the WHERE clause and inspects affected rows to detect conflicts.

Optimistic locking with @VersionColumn

Optimistic locking implementation notes:

1
@VersionColumn() stores an integer that TypeORM increments on every save automatically.
2

How do you implement optimistic locking with TypeORM to prevent lost updates in NestJS?

How do you implement optimistic locking with TypeORM to prevent lost updates in NestJS?

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