SQL to C# Model

How the SQL to C# Model works

The converter reads your SQL with a tokenizer for the chosen dialect, finds every CREATE TABLE statement and reads its column list: each column's name, type with its length or precision, NOT NULL, PRIMARY KEY (on the column or as a table constraint), and identity markers such as IDENTITY, AUTO_INCREMENT, SERIAL or GENERATED ... AS IDENTITY. Other statements in the input, such as GO or ALTER TABLE, are skipped.

Each table becomes a class named after the table in PascalCase (optionally made singular), and each column becomes a property with a C# type chosen for that dialect. Value types for columns that allow NULL get a ?. When the property name is not exactly the column name and data annotations are on, a [Column] attribute keeps the mapping to the database. Nothing is run against a database.

How to use the SQL to C# Model

1. Paste one or more CREATE TABLE statements into the input box, open a .sql file, or select Load example.
2. Choose the dialect the statements were written for, then set the namespace and whether property names should be PascalCase or kept as in SQL.
3. Tick Data annotations, Nullable reference types or Singular class names if you want them.
4. Select Convert to C#, or press Ctrl + Enter (Cmd + Enter on a Mac), then copy the classes or download them as a .cs file.

Example

This table:

CREATE TABLE dbo.order_items (
    id INT IDENTITY(1, 1) PRIMARY KEY,
    product_name NVARCHAR(200) NOT NULL,
    unit_price DECIMAL(10, 2) NOT NULL,
    shipped_at DATETIME2 NULL
);

becomes, with the namespace MyApp.Models and the other options off:

using System;

namespace MyApp.Models
{
    public class OrderItems
    {
        public int Id { get; set; }
        public string ProductName { get; set; }
        public decimal UnitPrice { get; set; }
        public DateTime? ShippedAt { get; set; }
    }
}

With Singular class names ticked the class is named OrderItem, and with Data annotations ticked ProductName gets [Required], [MaxLength(200)] and [Column("product_name")].

Common use cases

• Creating entity classes for an existing database table when starting an Entity Framework Core or Dapper project.
• Keeping DTOs in step with a table after new columns were added in a migration script.
• Turning a schema exported from SQL Server Management Studio, pg_dump or SHOW CREATE TABLE into model classes.
• Checking which C# type a SQL column type such as DATETIMEOFFSET, TINYINT(1) or NUMERIC maps to.

Common errors and how to fix them

A CREATE TABLE statement is missing its table name

The parser reads CREATE TABLE statements, so the input must be one. Paste the full statement including the table name and the bracketed column list, not just the column lines.

Expected ( and a column list after CREATE TABLE

The statement ends before its column definitions, usually because only the first line was copied. Include everything from the opening bracket through to the matching closing bracket.

An int column was generated as int?

Nullable SQL columns map to nullable C# types. If the column should never be null, declare it NOT NULL in the source statement and generate again.

A vendor type was not recognised

Select the dialect that matches your statement before generating. Types that exist only in one database, or user-defined types, have no direct C# equivalent and need mapping by hand.

Frequently asked questions