how to use Microsoft.Data.SqlClient in the .netcoreapp 2.1

1st you have to install package Microsoft.EntityFrameworkCore.SqlServer from Nuget Manager

After that mapped connection in appSettings.json

After that import namespace in your controller page

After that create connection object and bind, insert & update as you want.

public DataTable GetDataTable(string strQuery)
{
    DataTable dt = new DataTable();
    string connectionString = _configuration.GetConnectionString("DefaultConnection");

    string strQuery = "select *from users where empid='user1' and pwd='abc@123' ";

    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        SqlDataAdapter adapter = new SqlDataAdapter(strQuery, connection);
        adapter.Fill(dt);
    }

    return dt;
}

Getting this error , The type initializer for 'Microsoft.Data.SqlClient.SqlConnection' threw an exception.

If your application runs on the same machine as SQL Server, try:

string connectionString = @"Server=WIN-KOQSELR3408\SQLEXPRESS;Database=Test;Integrated Security=True;TrustServerCertificate=True;";

Install -Package Microsoft.Data.SqlClient -Version 2.1.0 either by using commands or using Nuget Package update connection string as per yours.

using System;
using System.Data;
using Microsoft.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "Server=your_server;Database=your_db;User Id=your_user;Password=your_password;";

        using (SqlConnection conn = new SqlConnection(connectionString))
        {
            try
            {
                conn.Open();
                Console.WriteLine("Connected to database!");

                string query = "SELECT TOP 1 * FROM YourTable";
                using (SqlCommand cmd = new SqlCommand(query, conn))
                {
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            Console.WriteLine(reader[0]); // Print first column of the first row
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error: " + ex.Message);
            }
        }
    }
}