create Database use C#

Question

I want create the database file using c#.I have a code bellow to test but that file not appear.

If cant, somebody show me .May be a little step.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DataBase_
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {

            GetDbCreationQuery();
        }

        static string GetDbCreationQuery()
        {
            // your db name
            string dbName = "Test_data";

            // path to your db files:
            // ensure that the directory exists and you have read write permission.
            string[] files = { Path.Combine(Application.StartupPath, dbName + ".mdf"),
                       Path.Combine(Application.StartupPath, dbName + ".ldf") };

            // db creation query:
            // note that the data file and log file have different logical names
            string query = "CREATE DATABASE " + dbName +
                " ON PRIMARY" +
                " (NAME = " + dbName + "_data," +
                " FILENAME = '" + files[0] + "'," +
                " SIZE = 3MB," +
                " MAXSIZE = 10MB," +
                " FILEGROWTH = 10%)" +

                " LOG ON" +
                " (NAME = " + dbName + "_log," +
                " FILENAME = '" + files[1] + "'," +
                " SIZE = 1MB," +
                " MAXSIZE = 5MB," +
                " FILEGROWTH = 10%)" +
                ";";

            return query;
        }
    }
}

Answer 1

The following page does what you need, create a new SQL-Server database.

Edited version, original version used localhost while my revision uses \\SQLEXPRESS and placed into a class.

using System;  
using System.Data.SqlClient;  
using System.IO;  
using System.Windows.Forms;  
  
namespace CreateDatabase  
{  
    public partial class Form1 : Form  
    {  
        public Form1()  
        {  
            InitializeComponent();  
        }  
  
        private void CreateButton_Click(object sender, EventArgs e)  
        {  
            var (success, exception) = DataOperations.CreateDatabase();  
            if (success)  
            {  
                MessageBox.Show("Done");      
            }  
            else  
            {  
                MessageBox.Show($"{exception.Message}");  
            }  
        }  
    }  
  
    public class DataOperations  
    {  
        public static (bool success, Exception exception) CreateDatabase()  
        {  
            var fileName = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Sample.mdf");  
            var ldfFileName = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Sample.ldf");  
  
            string connectionString = "Data Source=.\\SQLEXPRESS;Initial Catalog=master;Integrated Security=True";  
  
            var commandText = "CREATE DATABASE MyDatabase ON PRIMARY " +  
                              "(NAME = MyDatabase_Data, " +  
                              $"FILENAME = '{fileName}', " +  
                              "SIZE = 2MB, MAXSIZE = 10MB, FILEGROWTH = 10%)" +  
                              "LOG ON (NAME = MyDatabase_Log, " +  
                              $"FILENAME = '{ldfFileName}', " +  
                              "SIZE = 1MB, " +  
                              "MAXSIZE = 5MB, " +  
                              "FILEGROWTH = 10%)";  
  
  
  
            using (var cn = new SqlConnection(connectionString))  
            {  
                using (var cmd = new SqlCommand(commandText, cn))  
                {  
  
                    try  
                    {  
                        cn.Open();  
                        cmd.ExecuteNonQuery();  
                        return (true, null);  
                    }  
                    catch (Exception e)  
                    {  
                        return (false, e);  
                    }  
                }  
                  
            }  
        }  
    }  
}  
  

Answer 2

The code you posted just returns a string...

See old threads like Create .mdf file in code

Answer 3

Hi there!
If you have a small desktop program that does not envisage many simultaneous users I would advise you to use SQLite database. It is very easy to catch up. But if you are building a more sophisticated application, you may want to use Microsoft SQL Server. SQLite vs SQL Server Comparison