VQuery 1.0.6

VQuery

A lightweight, high-performance database library for .NET — one simple API for MySQL, PostgreSQL, and SQL Server.

Why VQuery?

Most .NET projects end up choosing between hand-written ADO.NET (verbose, repetitive) or a full ORM like EF Core (heavy, opinionated, slow to set up for simple apps). VQuery sits in between:

• 🔌 One API, three databases — switch between MySQL, PostgreSQL, and SQL Server without rewriting your data layer
• ⚡ Fast — reflection caching means object mapping doesn't slow you down as your app grows
• 🪶 Lightweight — no heavy configuration, no migrations engine, no fighting the framework
• 🧵 Async-first — every core operation has an async counterpart
• 🔒 Safe by default — parameterized queries throughout

If you want Dapper-like simplicity with built-in multi-database support out of the box, VQuery is built for that.

Status: MySQL support is the most tested and battle-tested part of VQuery. PostgreSQL and SQL Server support exist and follow the same API, but have seen less real-world use so far — feedback and bug reports for those are especially welcome.

Installation

dotnet add package VQuery

Or via the Package Manager Console:

Install-Package VQuery

Quick Start

1. Add a connection string to appsettings.json:

{
  "ConnectionStrings": {
    "MYSQLConnection": {
      "server": "127.0.0.1",
      "port": "3306",
      "database": "sampledb",
      "username": "root",
      "password": "123456"
    }
  }
}

2. Query in three lines:

using VQuery;

using var db = new MySQLConnection();
db.ConnectionOpen("MYSQLConnection");

var users = db.Query<User>("SELECT * FROM users");

Swap MySQLConnection for PostgreSQLConnection or SQLServerConnection and everything else stays the same.

Core Features

Usage Examples

CRUD

// Insert
db.Insert("users", new Dictionary<string, string>
{
    { "name", "John" },
    { "email", "john@test.com" }
});

// Update
db.Update("users", new Dictionary<string, string>
{
    { "name", "David" }
}, "id=1");

// Delete (parameterized)
db.Delete("DELETE FROM users WHERE id=@id", new() { ["@id"] = 1 });

Note: Insert() and Update() also have overloads that take Dictionary<string, object> instead of Dictionary<string, string>. Prefer the object overloads when your values include numbers, dates, or booleans — the string overloads pass every value through as VARCHAR.

Check existence

bool hasAdmins = db.Exists("SELECT 1 FROM users WHERE role=@role", new() { ["@role"] = "admin" });

bool hasAdminsAsync = await db.ExistsAsync("SELECT 1 FROM users WHERE role=@role", new() { ["@role"] = "admin" });

Transactions

db.Begin();
try
{
    db.Insert("users", new Dictionary<string, string> { { "name", "John" } });
    db.Update("users", new Dictionary<string, string> { { "name", "David" } }, "id=1");
    db.Commit();
}
catch
{
    db.RollBack();
}

Async

var users = await db.QueryAsync<User>("SELECT * FROM users");

var user = await db.QueryFirstAsync<User>(
    "SELECT * FROM users WHERE id=@id",
    new() { ["@id"] = 1 });

Safe single-record lookups

// Returns default(T) instead of throwing when no row is found
var user = db.QueryFirstOrDefault<User>(
    "SELECT * FROM users WHERE id=@id", new() { ["@id"] = 1 });

var userAsync = await db.QueryFirstOrDefaultAsync<User>(
    "SELECT * FROM users WHERE id=@id", new() { ["@id"] = 1 });

QuerySingle<T>() / QuerySingleOrDefault<T>() (and their async versions) work the same way, but throw if more than one row is returned.

VariableConverter utilities

Available directly on the connection object for quick type conversions:

db.ToInt("100");                     // -> 100
db.ToDouble("123.45");               // -> 123.45
db.ToIntString(100);                 // -> "100"
db.ToDoubleString(123.45);           // -> "123.45"
db.ToString(DateTime.Now);           // -> formatted string
db.ToStringDate(DateTime.Now);       // -> "dd-MM-yyyy" by default
db.ToStringDateTime(DateTime.Now);   // -> "dd-MM-yyyy HH:mm:ss" by default
db.ToDate("01-01-2026");             // -> DateTime
db.ToDateTime("01-01-2026 10:00:00");// -> DateTime
db.NumberToText(1000);               // -> number spelled out in words
db.NumberToTextKH(1000);             // -> number spelled out in Khmer
db.NumberToKhNumber(1000);           // -> number in Khmer numerals
db.IsEmpty(row);                     // -> true if a DataRow has no data

Multiple result sets

string sql = @"
    SELECT * FROM users;
    SELECT * FROM roles;
";

DataSet ds = db.QueryMultiple(sql);
DataTable users = ds.Tables[0];
DataTable roles = ds.Tables[1];

Configuration Reference

Each connection block in appsettings.json supports:

Supported Frameworks

• .NET 8.0 (also compatible with .NET 9.0 / 10.0)

Dependencies

• Microsoft.Data.SqlClient (>= 7.0.1)
• Microsoft.Extensions.Configuration.Json (>= 8.0.0)
• MySql.Data (>= 8.4.0)
• Npgsql (>= 8.0.3)

Contributing

Issues and pull requests are welcome! If you find a bug or have a feature request, please open an issue.

License

MIT — free to use in personal and commercial projects.

Links

• 📦 NuGet Package
• 💻 Source Code