SQL to TypeScript– Generate Interfaces from SQL

Convert CREATE TABLE statements to TypeScript interfaces with proper type mappings.

Paste SQL CREATE TABLE statement

Valid SQL

TypeScript Output

Why Use Our SQL to TypeScript Converter?

Type-Safe Output

Generates proper TypeScript with correct type mappings from SQL.

Nullable Handling

NOT NULL becomes required; nullable columns become optional.

PascalCase Names

Table names automatically converted to PascalCase interfaces.

All SQL Types

Handles INT, VARCHAR, BOOLEAN, DATE, JSON, and more.

100% Private

Schema never leaves your browser. Safe for production schemas.

Instant Convert

Get TypeScript interfaces in milliseconds with zero setup.

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Complete SQL to TypeScript Guide

Generating TypeScript interfaces from SQL schemas bridges the gap between your database layer and application code. When your TypeScript types match your database columns exactly, you catch type mismatches at compile time rather than at runtime, preventing entire categories of bugs.

Manually writing TypeScript interfaces for database tables is tedious and error-prone. Every time a migration adds or modifies a column, the corresponding TypeScript type must be updated. Automated generation eliminates this synchronization burden and ensures types are always accurate.

Our converter handles the complete type mapping: SQL numeric types (INT, BIGINT, DECIMAL, FLOAT) become number, text types (VARCHAR, TEXT, CHAR) become string, BOOLEAN becomes boolean, temporal types become Date, and JSON types become Record<string, unknown>.

Nullable columns (those without NOT NULL) generate optional properties with the ? modifier, accurately reflecting that the database may return null for these fields.

Complete reference for how SQL data types map to TypeScript types:

SQL Type	TypeScript Type	Notes
INT, BIGINT, SMALLINT, TINYINT	number	All integer variants
DECIMAL, FLOAT, DOUBLE, NUMERIC	number	Floating-point types
VARCHAR, TEXT, CHAR, LONGTEXT	string	All text types
BOOLEAN, BOOL	boolean	True/false values
DATE, DATETIME, TIMESTAMP	Date	Temporal types
JSON, JSONB	Record<string, unknown>	Structured JSON data

For BIGINT values exceeding JavaScript's Number.MAX_SAFE_INTEGER, consider using bigint instead of number in your application code.

Beyond basic interfaces, production TypeScript codebases benefit from derived types:

Creation Types

Derive a creation type that omits auto-generated fields (id, created_at) using TypeScript Omit utility: type CreateUser = Omit<User, 'id' | 'created_at'>

Update Types

Create partial update types using Partial utility: type UpdateUser = Partial<Omit<User, 'id'>> allows updating any subset of fields.

Query Result Types

Use Pick for SELECT projections: type UserSummary = Pick<User, 'name' | 'email'> matches queries selecting specific columns.

Branded Types

Use branded types for IDs to prevent mixing: type UserId = number & { __brand: 'UserId' } catches assignment errors at compile time.

These patterns create a type-safe data access layer that catches errors during development rather than in production.

Generated TypeScript interfaces integrate with popular database tools:

Prisma

Prisma generates its own types from schema.prisma, but generated interfaces help validate that Prisma types match your actual database schema. Use them as reference types for API responses.

TypeORM

TypeORM entities use decorators but the underlying interface structure matches our output. Use generated interfaces as the shape for your @Entity classes with added decorators.

Drizzle ORM

Drizzle's schema definitions are close to SQL. Generated interfaces verify your Drizzle schema matches the database. Use InferModel to derive types from Drizzle schemas.

Raw SQL with pg/mysql2

When using raw SQL drivers, generated interfaces type your query results directly. Cast query results to generated types for type-safe data access without an ORM.

Regardless of your database access pattern, TypeScript interfaces from SQL schemas provide a single source of truth for data shapes throughout your application.

Regenerate after migrations: Every database migration should trigger regeneration of TypeScript types. Integrate this into your migration workflow to prevent drift.
Separate model and API types: Database models may differ from API response shapes. Generate base types from SQL, then derive API-specific types using Pick, Omit, and intersection types.
Handle null vs undefined: SQL NULL maps to TypeScript null, but optional properties can also be undefined. Use strict null checks and be explicit about null handling in your codebase.
Add JSDoc comments: Enhance generated interfaces with JSDoc comments documenting field meanings, valid ranges, and business rules that SQL types alone cannot express.
Version your types: Store generated types in version control. Changes to types serve as documentation of schema evolution and enable code review of database changes.

Consistent type generation practices ensure your TypeScript application stays synchronized with your database schema throughout the development lifecycle.

How does SQL to TypeScript conversion work?

The converter parses CREATE TABLE statements, extracts column names and SQL data types, then generates TypeScript interfaces with properly mapped types. INT becomes number, VARCHAR becomes string, BOOLEAN becomes boolean, and TIMESTAMP becomes Date.

Which SQL statements are supported?

CREATE TABLE statements with column definitions, constraints (NOT NULL, PRIMARY KEY, UNIQUE, DEFAULT, AUTO_INCREMENT), and common SQL data types from MySQL, PostgreSQL, and SQL Server.

How are SQL types mapped to TypeScript?

INT/BIGINT/DECIMAL/FLOAT/DOUBLE map to number. VARCHAR/TEXT/CHAR map to string. BOOLEAN/BOOL map to boolean. DATE/DATETIME/TIMESTAMP map to Date. JSON/JSONB map to Record<string, unknown>.

Does it handle nullable columns?

Yes. Columns without NOT NULL constraint generate optional properties (propertyName?: type) in TypeScript, reflecting that the database allows null values for those fields.

Can it generate interfaces for multiple tables?

Currently it processes one CREATE TABLE statement at a time. For multiple tables, convert each separately and combine the generated interfaces in your TypeScript project.

Does it preserve table and column comments?

SQL comments and COMMENT clauses are not currently included in the TypeScript output. You can add JSDoc comments manually to the generated interfaces for documentation.

How are primary keys and constraints handled?

PRIMARY KEY, FOREIGN KEY, UNIQUE, INDEX, and CHECK constraints are recognized and excluded from the property list since they are metadata, not data fields. PRIMARY KEY columns are included as regular properties.

Can I use the output with ORMs like Prisma or TypeORM?

The generated interfaces are standard TypeScript and work as a starting point. ORMs typically require their own decorator syntax or schema files, but the interface structure maps directly to entity shapes.

How are AUTO_INCREMENT columns handled?

AUTO_INCREMENT columns are included as regular number properties. In practice, you might want to make these optional in creation types since the database assigns the value.

What naming convention is used for interfaces?

Table names are converted to PascalCase: 'user_profiles' becomes 'UserProfiles', 'orders' becomes 'Orders'. Column names remain as-is to match database field names.

Is this tool secure for production schemas?

Yes. All processing happens in your browser. Your database schema never leaves your device, is not transmitted anywhere, and is not stored.

How do I handle enum types from SQL?

SQL ENUM types are currently mapped to string in TypeScript. For stricter typing, you can manually create TypeScript union types or enums based on the allowed values from your schema.

SQL to TypeScript Tool

Why Use Our SQL to TypeScript Converter?

Other SQL Tools

Complete SQL to TypeScript Guide