VOCABULARY

TypeORM NestJS Guide - Vocabulary & Glossary

This document provides a comprehensive glossary of TypeORM, NestJS, TypeScript, and database terms used throughout this guide.

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Table of Contents

1. TypeORM Core Terms
2. Entity & Column Terms
3. Relationship Terms
4. Query & Repository Terms
5. NestJS Framework Terms
6. TypeScript Terms
7. Database Terms
8. Transaction & Locking Terms
9. Security & Authentication Terms
10. Performance & Optimization Terms
11. Testing Terms
12. Deployment & DevOps Terms

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TypeORM Core Terms

Term	Full Form	Description
ORM	Object-Relational Mapping	Technique for converting between database and object-oriented code
TypeORM	TypeScript ORM	ORM framework for TypeScript and JavaScript
DataSource	DataSource	Main connection manager in TypeORM
Entity	Entity	Class that maps to a database table
Repository	Repository	Pattern for data access abstraction
EntityManager	EntityManager	Interface for database operations on entities
QueryBuilder	QueryBuilder	Fluent API for building complex SQL queries
Migration	Migration	Version control for database schema changes
Subscriber	Subscriber	Event listener for entity lifecycle events
CLI	Command Line Interface	TypeORM’s command-line tool

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Entity & Column Terms

Term	Full Form	Description
@Entity	Decorator	Decorator that marks a class as a database entity
@Column	Decorator	Decorator that marks a property as a database column
@PrimaryColumn	Primary Column	Decorator for manually defined primary key
@PrimaryGeneratedColumn	Generated Primary Column	Decorator for auto-generated primary key
@PrimaryGeneratedColumn(‘uuid’)	UUID Primary	Auto-generated UUID as primary key
@PrimaryGeneratedColumn(‘increment’)	Auto-increment Primary	Auto-incrementing integer primary key
@CreateDateColumn	Create Date Column	Auto-set creation timestamp column
@UpdateDateColumn	Update Date Column	Auto-update timestamp column
@DeleteDateColumn	Delete Date Column	Soft delete timestamp column
@VersionColumn	Version Column	Optimistic locking version field
@Index	Index	Database index decorator
@Unique	Unique Constraint	Unique constraint decorator
@Check	Check Constraint	Custom check constraint decorator
Embedded	Embedded Entity	Entity embedded in another entity
@VirtualColumn	Virtual Column	Non-persisted computed column

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Relationship Terms

Term	Full Form	Description
@OneToOne	One-to-One	Single entity relation to another entity
@OneToMany	One-to-Many	Single entity relates to multiple entities
@ManyToOne	Many-to-One	Multiple entities relate to single entity
@ManyToMany	Many-to-Many	Multiple entities relate to multiple entities
@JoinColumn	Join Column	Foreign key column definition
@JoinTable	Join Table	Junction table for many-to-many relations
Eager Loading	Eager Loading	Auto-load relations with parent entity
Lazy Loading	Lazy Loading	Load relations on-demand (Promise-based)
RelationId	Relation ID	Load only foreign key values
Inverse Side	Inverse Side	The “other” side of a relationship
Owning Side	Owning Side	The side that owns the foreign key
Cascade	Cascade	Auto-propagate operations to related entities
Orphan Removal	Orphan Removal	Remove orphaned related entities

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Query & Repository Terms

Term	Full Form	Description
Find Options	Find Options	Configuration object for find operations
FindOneOptions	Find One Options	Options for findOne/findOneBy methods
FindManyOptions	Find Many Options	Options for find method
SelectQueryBuilder	Select Query Builder	Builder for SELECT queries
InsertQueryBuilder	Insert Query Builder	Builder for INSERT queries
UpdateQueryBuilder	Update Query Builder	Builder for UPDATE queries
DeleteQueryBuilder	Delete Query Builder	Builder for DELETE queries
Subquery	Subquery	Query nested within another query
Raw Query	Raw Query	Direct SQL execution
Parameterized Query	Parameterized Query	SQL with placeholders for values
N+1 Problem	N+1 Problem	Query pattern causing performance issues
Eager Relation	Eager Relation	Automatically loaded relationship
Lazy Relation	Lazy Relation	On-demand loaded relationship
Pagination	Pagination	Dividing results into pages
Cursor Pagination	Cursor Pagination	Pagination using last item as cursor
Offset Pagination	Offset Pagination	Pagination using skip/take

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NestJS Framework Terms

Term	Full Form	Description
NestJS	NestJS	Progressive Node.js framework
Module	Module	Organization unit that groups related code
Controller	Controller	Handles incoming HTTP requests
Service	Service	Business logic layer
Provider	Provider	Injectable class (Service, Repository, etc.)
Injectable	Injectable	Decorator marking a class as injectable
Inject	Inject	Decorator for dependency injection
@Module	Module Decorator	Decorator for defining NestJS modules
@Controller	Controller Decorator	Decorator for defining controllers
@Service	Service Decorator	Decorator for defining services
@Get	GET Decorator	Decorator for GET HTTP method
@Post	POST Decorator	Decorator for POST HTTP method
@Put	PUT Decorator	Decorator for PUT HTTP method
@Delete	DELETE Decorator	Decorator for DELETE HTTP method
@Patch	PATCH Decorator	Decorator for PATCH HTTP method
@Body	Body Decorator	Extract request body
@Param	Param Decorator	Extract route parameters
@Query	Query Decorator	Extract query parameters
@Headers	Headers Decorator	Extract request headers
Guard	Guard	Authorization/permission check
Interceptor	Interceptor	Transform request/response
Pipe	Pipe	Transform/validate input data
Filter	Filter	Exception handling
Middleware	Middleware	Request/response preprocessing
DTO	Data Transfer Object	Object for transferring data between layers
@Injectable	Injectable Decorator	Decorator marking class as injectable
ForwardRef	Forward Reference	Handle circular dependencies

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TypeScript Terms

Term	Full Form	Description
TypeScript	TypeScript	Typed superset of JavaScript
TS	TypeScript	Short form for TypeScript
Type	Type	Type annotation in TypeScript
Interface	Interface	Blueprint for object structure
Class	Class	Blueprint for creating objects
Enum	Enumeration	Set of named constant values
Generic	Generic	Parameterized type
Decorator	Decorator	Special declaration attaching metadata
Type Guard	Type Guard	Runtime type checking
Union Type	Union Type	Multiple possible types
Intersection	Intersection	Combining types
Optional	Optional	Nullable/undefined type
Never	Never Type	Type that never occurs
Any	Any Type	Opt-out of type checking
Unknown	Unknown Type	Type-safe any
Void	Void	No return value
Never	Never	Function that never returns
Arrow Function	Arrow Function	Short function syntax (=>)
Async/Await	Async/Await	Asynchronous code syntax
Promise	Promise	Represents eventual completion
Await	Await	Pauses execution for Promise
Partial	Partial	Makes all properties optional
Required	Required	Makes all properties required
Readonly	Readonly	Makes properties immutable
Pick	Pick	Select specific properties
Omit	Omit	Exclude specific properties

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Database Terms

Term	Full Form	Description
SQL	Structured Query Language	Language for managing relational databases
RDBMS	Relational Database Management System	Software for managing relational databases
PostgreSQL	PostgreSQL	Advanced open-source RDBMS
MySQL	MySQL	Popular open-source RDBMS
MariaDB	MariaDB	MySQL fork
SQLite	SQLite	Embedded database
Table	Table	Collection of related data in rows/columns
Row	Row	Single record in a table
Column	Column	Attribute in a table
Primary Key	Primary Key	Unique identifier for each row
Foreign Key	Foreign Key	Reference to another table’s primary key
Index	Index	Data structure for fast lookups
Unique Index	Unique Index	Index enforcing uniqueness
Composite Index	Composite Index	Index on multiple columns
Constraint	Constraint	Rule enforced on data
NULL	NULL	Missing or unknown value
ACID	Atomicity, Consistency, Isolation, Durability	Database transaction properties
Normalization	Normalization	Organizing data to reduce redundancy
Denormalization	Denormalization	Adding redundancy for performance
Schema	Schema	Database structure definition
Migration	Migration	Database version control
View	View	Virtual table based on query
Stored Procedure	Stored Procedure	Precompiled SQL code
Trigger	Trigger	Automated action on events
Function	Function	Reusable SQL code
CTE	Common Table Expression	Temporary named result set
JOIN	JOIN	Combine rows from tables
INNER JOIN	Inner Join	Matched rows from both tables
LEFT JOIN	Left Join	All rows from left + matched right
RIGHT JOIN	Right Join	All rows from right + matched left
FULL OUTER	Full Outer Join	All rows from both tables
Self Join	Self Join	Table joined with itself
Cross Join	Cross Join	Cartesian product

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Transaction & Locking Terms

Term	Full Form	Description
Transaction	Transaction	Atomic database operation unit
ACID	ACID	Atomicity, Consistency, Isolation, Durability
Atomicity	Atomicity	All or nothing operation
Consistency	Consistency	Valid state after transaction
Isolation	Isolation	Concurrent transaction independence
Durability	Durability	Persisted after commit
Commit	Commit	Save transaction changes
Rollback	Rollback	Undo transaction changes
Savepoint	Savepoint	Partial rollback point
Isolation Level	Isolation Level	Transaction concurrency control
Dirty Read	Dirty Read	Reading uncommitted data
Non-repeatable Read	Non-repeatable Read	Different results on re-read
Phantom Read	Phantom Read	New rows appear on re-read
Pessimistic Lock	Pessimistic Lock	Lock before reading
Optimistic Lock	Optimistic Lock	Lock on update attempt
Lock Mode	Lock Mode	Type of database lock
Row Lock	Row Lock	Lock on specific row
Table Lock	Table Lock	Lock on entire table
Deadlock	Deadlock	Two transactions waiting indefinitely
Transaction Manager	Transaction Manager	Handles transaction lifecycle
@Transactional	Transactional Decorator	Auto-transaction wrapper

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Security & Authentication Terms

Term	Full Form	Description
JWT	JSON Web Token	Compact, URL-safe token format
Access Token	Access Token	Short-lived authorization token
Refresh Token	Refresh Token	Long-lived token for new access tokens
Bearer Token	Bearer Token	Token sent in Authorization header
OAuth	OAuth	Authorization framework
OAuth 2.0	OAuth 2.0	OAuth protocol version
OpenID	OpenID	Authentication protocol
SSO	Single Sign-On	One login for multiple services
Password Hashing	Password Hashing	One-way encryption for passwords
bcrypt	bcrypt	Password hashing algorithm
Argon2	Argon2	Modern password hashing algorithm
Salt	Salt	Random data added before hashing
Rainbow Table	Rainbow Table	Pre-computed hash lookup table
RBAC	Role-Based Access Control	Access based on user roles
ABAC	Attribute-Based Access Control	Access based on attributes
CORS	Cross-Origin Resource Sharing	Cross-origin request policy
CSRF	Cross-Site Request Forgery	Attack tricking user requests
XSS	Cross-Site Scripting	Attack injecting scripts
SQL Injection	SQL Injection	Attack inserting malicious SQL
Sanitization	Sanitization	Removing dangerous characters
Parameterized	Parameterized Query	Safe query with placeholders

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Performance & Optimization Terms

Term	Full Form	Description
Query Optimization	Query Optimization	Improving query performance
Execution Plan	Execution Plan	How database executes query
EXPLAIN	EXPLAIN	SQL command to show plan
Index Scan	Index Scan	Using index for data retrieval
Seq Scan	Sequential Scan	Full table scan
Index Only Scan	Index Only Scan	Reading only from index
Cache	Cache	In-memory data storage
Redis	Redis	In-memory data structure store
Connection Pool	Connection Pool	Reusable database connections
Pool Size	Pool Size	Maximum connections in pool
N+1 Query	N+1 Query	Multiple sequential queries
Batch Operation	Batch Operation	Bulk data processing
Lazy Loading	Lazy Loading	Load on demand
Eager Loading	Eager Loading	Load immediately
Caching Strategy	Caching Strategy	How to cache data
TTL	Time to Live	Cache expiration time
Warm Cache	Warm Cache	Pre-populated cache
Cold Cache	Cold Cache	Empty cache
Database Profiling	Database Profiling	Analyzing query performance
Slow Query	Slow Query	Query taking excessive time
Benchmarking	Benchmarking	Performance measurement

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Testing Terms

Term	Full Form	Description
Unit Test	Unit Test	Test single function/method
Integration Test	Integration Test	Test component interactions
E2E Test	End-to-End Test	Test complete user flows
Jest	Jest	JavaScript testing framework
Supertest	Supertest	HTTP testing for Express/NestJS
Test Fixture	Test Fixture	Pre-configured test data
Test Factory	Test Factory	Dynamic test data creation
Mock	Mock	Fake implementation for testing
Stub	Stub	Simplified test double
Spy	Spy	Function call tracking
Snapshot Test	Snapshot Test	UI/component comparison
Coverage	Coverage	Code execution measurement
Test Runner	Test Runner	Tool executing tests
Assertion	Assertion	Verification of expected result
Describe Block	Describe Block	Test group container
It Block	It Block	Individual test case
BeforeAll	BeforeAll	Setup before all tests
BeforeEach	BeforeEach	Setup before each test
AfterAll	AfterAll	Cleanup after all tests
AfterEach	AfterEach	Cleanup after each test
Test Database	Test Database	Isolated database for tests

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Deployment & DevOps Terms

Term	Full Form	Description
Docker	Docker	Container platform
Container	Container	Isolated application environment
Image	Docker Image	Container template
Dockerfile	Dockerfile	Container build instructions
Docker Compose	Docker Compose	Multi-container orchestration
Kubernetes	Kubernetes	Container orchestration
K8s	Kubernetes	Short form for Kubernetes
Pod	Pod	Kubernetes smallest deployable unit
Service	Kubernetes Service	Network abstraction for pods
Deployment	Deployment	Kubernetes resource for app updates
ConfigMap	ConfigMap	Kubernetes configuration storage
Secret	Secret	Kubernetes sensitive data storage
Helm	Helm	Kubernetes package manager
CI/CD	Continuous Integration/Deployment	Automated build and deployment
GitHub Actions	GitHub Actions	CI/CD platform
GitLab CI	GitLab CI	GitLab’s CI/CD tool
Jenkins	Jenkins	Automation server for CI/CD
Nginx	Nginx	Web server and reverse proxy
PM2	PM2	Process manager for Node.js
Environment Variables	Environment Variables	Configuration values per environment
dotenv	dotenv	Node.js environment loader

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Additional TypeORM-Specific Terms

Term	Full Form	Description
Synchronize	Synchronize	Auto-create database schema
Logging	Logging	SQL query logging
Entity Schema	Entity Schema	Programmatic entity definition
Naming Strategy	Naming Strategy	Database naming conventions
Metadata	Metadata	Entity/column metadata storage
Driver	Driver	Database-specific implementation
Connection Options	Connection Options	Database connection configuration
Multiple Connections	Multiple Connections	Multiple database connections
Replication	Replication	Database read replicas
Sharding	Sharding	Horizontal database partitioning
Entity Listener	Entity Listener	Lifecycle event handler
Event Arguments	Event Arguments	Data passed to event handlers
BeforeInsert	BeforeInsert	Event before entity insertion
AfterInsert	AfterInsert	Event after entity insertion
BeforeUpdate	BeforeUpdate	Event before entity update
AfterUpdate	AfterUpdate	Event after entity update
BeforeRemove	BeforeRemove	Event before entity removal
AfterRemove	AfterRemove	Event after entity removal
Soft Delete	Soft Delete	Mark as deleted instead of removing
Hard Delete	Hard Delete	Permanent row removal

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Quick Reference Card

Common Decorators Mapping

TypeORM	NestJS	Purpose
@Entity	@Module	Define entity/module
@Column	@Controller	Define column/controller
@PrimaryColumn	@Injectable	Primary key/injectable
@ManyToOne	@Inject	Relationship/injection
@Index	@UseGuards	Index/authorization
@JoinColumn	@Body	Join column/request body

Common Method Prefixes

Prefix	Purpose
find…	Retrieve data
save…	Insert/update data
remove…	Delete data
create…	Create entity instance
delete…	Remove data
count…	Count records
update…	Update records

Common Suffixes

Suffix	Purpose
…ById	Find by primary key
…One	Single result
…Many	Multiple results
…AndCount	With total count
…Raw	Raw query result

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Related Chapters

• Chapter 1: Introduction to TypeORM and NestJS
• Chapter 5: Connection Setup
• Chapter 11: Repository Pattern
• Chapter 16: Query Builder Fundamentals
• Chapter 21: Module Architecture

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Last Updated: February 2026