Top 20 NuGet Database Packages

Micro-orm & set of tiny, performant extension methods for SqlConnection, SqlCommand, SqlDataReader and SqlBulkCopy with a fluent api for building both SqlCommands and SqlBulkCopy routines.
SqlCommand and Reader Helpers
Light weight, high performance ORM for simple and robust data access for large scale applications
The official SQLite database engine for both x86 and x64 along with the ADO.NET provider. This package includes support for LINQ and Entity Framework 6.
Sqlite provider for DbSession.
AutoProc is a lightweight Asp.Net Core 2 middleware package which makes it easy to create a backend by exposing your stored procedures as an API.
Fluent, XML-less, compile safe, automated, convention-based mappings for NHibernate.
Easily build filters for use in Lambda Expressions. Make it easy to turn WebApi requests parameters into expressions. Great features such as; save and re-run those filters, make complex expressions and more!
Sqlite provider for Storm.
Super-Tiny ORM framework.
Sqlite provider for DbSession.
Dapper extensions for sdmap.
This library helps to convert sql query result to JSON. This can help if your database does not provide such a feature (e.g. Oracle). The mapping can be configured with a nice fluent interface.
Easily generate SQL INSERT statements for large amount of random test data
EasyToMySql or ETM will help you making better connection experience to MySql. When you can just type the target table, host or .. address instead of defining and making instances of MySql libraries.
Bulk Data API/Tools for SQL Server databases. Easily perform bulk "upsert" operations on your database. Nifty helper utility for moving around large sets of data.
Dapper extensions for sdmap.
Tiny CRUD operation ADO.NET for FirebirdSql and Sqlite providers
A contribution to the Microsoft EntityFramework
Fluid-style SQL statement generator