What is SQL to Entity Framework Core Converter?

Entity Framework Core (EF Core) is Microsoft's modern object-database mapper for .NET, supporting LINQ queries, change tracking, migrations, and multiple database providers including SQL Server, PostgreSQL, MySQL, and SQLite. This converter transforms your SQL CREATE TABLE statements into C# entity classes decorated with data annotations like [Key], [Required], [Column], [Table], and [MaxLength]. It also generates a DbContext class with DbSet properties for each table, giving you a complete starting point for a Code First EF Core project.

How to Use

Paste your SQL CREATE TABLE statements into the input area on the left
Click "Generate" to produce C# entity classes with full data annotation attributes
Review the generated code — each table becomes a class with [Table] and [Column] attributes, and primary keys get [Key] and [DatabaseGenerated] decorators
Copy the output and add the entity classes and DbContext to your .NET project
Configure the database provider in the OnConfiguring method of the generated DbContext

Why Use This Tool?

Generates complete C# entity classes with data annotations that EF Core uses for schema mapping and validation

SQL types are mapped to idiomatic C# types — INTEGER becomes int, NUMERIC becomes decimal, UUID becomes Guid, TIMESTAMP becomes DateTime

Nullable SQL columns produce nullable C# reference types (string stays nullable by convention) and nullable value types (int?, DateTime?)

SERIAL and auto-increment columns receive [DatabaseGenerated(DatabaseGeneratedOption.Identity)] for proper identity handling

A DbContext class with DbSet properties is generated so you can start querying immediately with LINQ

Tips & Best Practices

The generated column type annotations use PostgreSQL naming by default — adjust the TypeName strings if you target SQL Server or MySQL
VARCHAR and CHAR columns include [MaxLength] attributes based on the type parameters, which EF Core uses for both schema generation and validation
Add navigation properties manually after generation — decorate foreign key columns with [ForeignKey] and related entities with [InverseProperty]
For financial calculations, prefer the C# decimal type (mapped from NUMERIC/DECIMAL) over float or double to avoid floating-point precision errors

Frequently Asked Questions

How are SQL types mapped to C# types in EF Core?

The mapping follows EF Core conventions: SERIAL/INTEGER becomes int, BIGINT becomes long, SMALLINT becomes short, TINYINT becomes byte, VARCHAR/TEXT becomes string, BOOLEAN becomes bool, NUMERIC/DECIMAL becomes decimal, REAL becomes float, DOUBLE becomes double, TIMESTAMP becomes DateTime, TIMESTAMPTZ becomes DateTimeOffset, UUID becomes Guid, BYTEA/BLOB becomes byte[], JSON/JSONB becomes string. Nullable SQL columns produce nullable C# types like int? and DateTime?.

When should I avoid using EF Core?

EF Core adds overhead for change tracking and translation layers. Avoid it for read-heavy analytics workloads where raw ADO.NET or Dapper would be faster, for extremely performance-sensitive write paths, or when you need database-specific features that EF Core cannot express through LINQ. For those cases, consider Dapper or raw ADO.NET.

Does the converter support foreign key relationships?

The current version focuses on entity class generation with data annotations. Foreign key columns are mapped as regular properties. You can manually add navigation properties using [ForeignKey] and [InverseProperty] attributes after generation to enable EF Core relationship management and eager/lazy loading.

Which database providers work with the generated code?

The entity classes work with any EF Core provider. The column type annotations default to PostgreSQL naming (e.g., character varying, timestamp without time zone), but you can adjust the TypeName values for SQL Server (nvarchar, datetime2), MySQL, or SQLite as needed.

Is my SQL data sent to a server?

No. All parsing and code generation happens entirely in your browser using a client-side parser. Your SQL schema is never transmitted over the network, and no external services are contacted.

Real-world Examples

ASP.NET Core API with EF Core entities

A .NET developer building a REST API pastes their existing PostgreSQL schema into this tool, generates entity classes with data annotations, and uses them with EF Core in their ASP.NET Core controllers. The generated DbContext is registered in Startup.cs and injected into services.

Input

CREATE TABLE products (
  id SERIAL PRIMARY KEY,
  name VARCHAR(200) NOT NULL,
  price NUMERIC(10,2) NOT NULL,
  category VARCHAR(50),
  in_stock BOOLEAN DEFAULT true,
  created_at TIMESTAMP DEFAULT NOW()
);

Output

[Table("products")]
public class Product
{
  [Key]
  [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
  [Column("id", TypeName = "serial")]
  public int Id { get; set; }

  [Required]
  [MaxLength(200)]
  [Column("name", TypeName = "character varying(200)")]
  public string Name { get; set; }
}

Migrating legacy database to Code First

A team with an existing MySQL database uses this converter to generate EF Core entity classes from their schema, enabling them to adopt Code First migrations and version-control their database schema alongside their C# code.

SQL to Entity Framework Core Converter