What decorators does NestJS provide for route parameters and how do they differ from query params?

Q: What decorators does NestJS provide for route parameters and how do they differ from query params?

@Controller('users') export class UsersController { // Route param — part of the URL path: GET /users/42 @Get(':id') findOne(@Param('id') id: string) {} // Multiple route params: GET /users/42/posts/7 @Get(':userId/posts/:postId') findPost( @Param('userId') userId: string, @Param('postId') postId: string, ) {} // Whole params object at once @Get(':id') findOneAll(@Param() params: { id: string }) {} // Query param — comes after ?: GET /users?page=2&limit=10 @Get() findAll(@Query('page') page: string) {} } Route params — mandatory resource identifiers that are part of the URL path structure. Query params — optional modifiers for filtering, sorting, searching, and pagination. Route params are always strings before transformation — use ParseIntPipe or ParseUUIDPipe. @Param('key') extracts a single named param; @Param() with no arg injects the entire params object. @Query('key') extracts a single query value; @Query() with no arg injects the full query object.

Difficulty: 4/10

@Param decorator, @Query decorator, NestJS routing

Route parameters are path segments prefixed with : in the route definition and are extracted with @Param(). Query parameters are key-value pairs after the ? in the URL and are extracted with @Query(). Route params identify a specific resource; query params filter, sort, or paginate a collection.

Route params vs query params

Route params vs query params — when to use each:

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Route params — mandatory resource identifiers that are part of the URL path structure.
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Query params — optional modifiers for filtering, sorting, searching, and pagination.
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What decorators does NestJS provide for route parameters and how do they differ from query params?

Route parameters are path segments prefixed with : in the route definition and are extracted with @Param(). Query parameters are key-value pairs after the ? in the URL and are extracted with @Query(). Route params identify a specific resource; query params filter, sort, or paginate a collection.

Scenario Questions

Follow-up Questions