If you working with .NET framework from a long time then you must have used SQL Helper or a similar library to work with SQL Server or if you working with some performance-critical applications and want to directly work with ADO.NET then you can use your ADO.NET with this SQL helper. I tried to convert it so that it can work with ADO.NET as well as achieve async feature as well in .NET Core 2.x.

So this SQL Helper Library basically has two main class file, that can be used easily for DML operations of SQL Database. A one just has to create an object and start using it.
The two class are,

• SQLHandler
• SQLHandlerAsync

And helper classes are

• DataSourceHelper
• Null

So this two SQLHandler and SQLHandlerAsync classes have pure ADO.NET methods like,

• ExecuteNonQuery and  ExecuteNonQueryAsync,
• ExecuteAsDataSet and ExecuteAsDataSetAsync,
• ExecuteAsDataReader and ExecuteAsDataReaderAsync,
• ExecuteAsObject and ExecuteAsObjectAsync,
• ExecuteAsList and ExecuteAsListAsync

Which can be used directly and can provide the best performance as required and handled from SQL Stored Procedures.

This SQLHandler and SQLHandlerAsync use NuGetPackage System.Data.SqlClient to support pure ADO.NET features like DataTable and DataSet etc.

Examples
How to use SQLHandlerAsync for ExecuteNonQueryAsync

public async Task<int> AddProject(ProjectInfo objInfo)
{
    List<KeyValuePair<string, object>> Param = new List<KeyValuePair<string, object>>();
    Param.Add(new KeyValuePair<string, object>("@ProjectName", objInfo.ProjectName));
    Param.Add(new KeyValuePair<string, object>("@ProjectCode", objInfo.ProjectCode));
    string strSpName = "usp_AddProject";
    SQLHandlerAsync sqlHAsy = new SQLHandlerAsync();
    return await sqlHAsy.ExecuteNonQueryAsync(strSpName, Param);
}

How to use SQLHandlerAsync for ExecuteAsObjectAsync

public async Task<ProjectInfo> GetProject(ProjectInfo objInfo)
{
    List<KeyValuePair<string, object>> Param = new List<KeyValuePair<string, object>>();
    Param.Add(new KeyValuePair<string, object>("@ProjectID", objInfo.ProjectID));            
    string strSpName = "usp_GetProject";
    SQLHandlerAsync sqlHAsy = new SQLHandlerAsync();
    //List<ProjectInfo> objList = await sqlHAsy.ExecuteAsListAsync<ProjectInfo>(strSpName, Param);
    return await sqlHAsy.ExecuteAsObjectAsync<ProjectInfo>(strSpName, Param);
}

How to use SQLHandlerAsync for ExecuteAsListAsync

public async Task<List<ProjectInfo>> GetProjectList()
{    
    string strSpName = "usp_GetProjectList";
    SQLHandlerAsync sqlHAsy = new SQLHandlerAsync();    
    return await sqlHAsy.ExecuteAsListAsync<ProjectInfo>(strSpName);
}

A source project is in Github a link is SQLHelper With ADO.NET SQL Helper

This repository has 3 projects, but SQL Helper is the main the rest two projects are just to test and shown as an example to use it.

A SQLHandler and SQLHandlerAsync both are partial classes so if required it can also accept more options too.

As these classes are for MS SQL only, it would be great if some friends can extend it for the mysql and mongodb etc too.

Hope it will help someone who need to work with ADO.NET in .NET Core.