LINQ to SQL Converter

What this tool does

Paste a C# LINQ query — method syntax (customers.Where(...).Select(...)) or query syntax (from c in customers where ... select ...) — and get an equivalent SQL statement. Everything runs in-memory in your Blazor session using a hand-written tokenizer and recursive-descent parser; nothing is sent to an external API, and no Roslyn/compiler dependency is involved.

Scope — what's actually supported

This is a rule-based translator for the common LINQ shapes, not a general-purpose query compiler (that's what EF Core's own provider does, with years of engineering behind it). Supported: Where, Select (including anonymous-object projections), OrderBy/OrderByDescending/ThenBy/ThenByDescending, GroupBy (single key, with Count() in the grouped projection), a single Join, Take/Skip, Count/Any/First/FirstOrDefault, and string Contains/StartsWith/EndsWith against a literal string (translated to LIKE). A bare boolean member (c.IsActive, or negated !c.IsActive) in a predicate is translated to IsActive = 1 / = 0, since T-SQL and PostgreSQL don't accept a bare column as a truthy predicate the way C# does.

Anything else — Sum/Average/Max/Min, Distinct, multiple joins, nested navigation properties (x.Address.City), non-literal Contains arguments, ternary expressions, custom method calls — is not guessed. It's listed explicitly in the warning box under the output so you know exactly what to fix by hand, rather than shipping SQL that looks plausible but is wrong.

Worked example

This method-syntax query:

customers
    .Where(c => c.Country == "USA" && c.IsActive)
    .OrderBy(c => c.LastName)
    .Select(c => new { c.FirstName, c.LastName, c.Email })

produces this SQL Server output:

SELECT [FirstName], [LastName], [Email]
FROM [customers]
WHERE ([Country] = 'USA') AND ([IsActive] = 1)
ORDER BY [LastName]

SQL Server vs PostgreSQL

The dialect toggle only changes two things: identifier quoting ([Brackets] for SQL Server vs "double quotes" for PostgreSQL) and how row-limiting is expressed (SELECT TOP (n) for SQL Server vs a trailing LIMIT n for PostgreSQL, with OFFSET handled per dialect for Skip). Every other part of the generated SQL is identical between the two.

How to use this tool

1. Pick a target dialect — SQL Server or PostgreSQL.
2. Paste a LINQ query in method or query syntax.
3. Click Convert (or Ctrl+Enter).
4. Check the warning box — if it's non-empty, review each listed construct before trusting the SQL.