How to import Data in csv file into a SQL Server database using C#

Question

I'm trying to import data into a SQL Server database from a .csv file. I have just one problem: for the money row, I am throwing Format.Exception due to wrong format of money variable.

I tried to convert to double I change the period instead of comma, I change in split(); method also semicolon ; instead of comma , but the exception didn't go away. Does anyone know what to do about this?

It is just an experiment.

My .csv file looks like this:

Database table's columns are:

name, second_Name, nickname, money

Code:

public void Import()
{
    SqlCommand command = null;
    var lineNumber = 0;

    using (SqlConnection conn = DatabaseSingleton.GetInstance())
    {
        // conn.Open();
        using (StreamReader reader = new StreamReader(@"C:\Users\petrb\Downloads\E-Shop\E-Shop\dataImport.csv"))
        {
            while (!reader.EndOfStream)
            {
                var line = reader.ReadLine();

                if (lineNumber != 0)
                {
                    var values = line.Split(',');

                    using (command = new SqlCommand("INSERT INTO User_Shop VALUES (@name, @second_Name, @nickname, @money", conn))
                    {
                        command.Parameters.Add(new SqlParameter("@name", values[0].ToString()));
                        command.Parameters.Add(new SqlParameter("@second_Name", values[1].ToString()));
                        command.Parameters.Add(new SqlParameter("@nickname", values[2].ToString()));
                        command.Parameters.Add(new SqlParameter("@money", Convert.ToDecimal(values[3].ToString())));
                        command.Connection = conn;

                        command.ExecuteNonQuery();
                    }
                }

                lineNumber++;
            }
        }

        conn.Close();
    }

    Console.WriteLine("Products import completed");
    Console.ReadLine();
}

Answer 1

I maintain a package Sylvan.Data.Csv that makes it very easy to bulk import CSV data into SQL Server, assuming the shape of your CSV file matches the target table.

Here is some code that demonstrates how to do it:

SqlConnection conn = ...;

// Get the schema for the target table
var cmd = conn.CreateCommand();
cmd.CommandText = "select top 0 * from User_Shop";
var reader = cmd.ExecuteReader();
var tableSchema = reader.GetColumnSchema();

// apply the schema of the target SQL table to the CSV data.
var options = 
    new CsvDataReaderOptions { 
        Schema = new CsvSchema(tableSchema)
    };

using var csv = CsvDataReader.Create("dataImport.csv", options);

// use sql bulk copy to bulk insert the data
var bcp = new SqlBulkCopy(conn);
bcp.BulkCopyTimeout = 0;
bcp.DestinationTableName = "User_Shop";
bcp.WriteToServer(csv);

On certain .NET framework versions GetColumnSchema might not exist, or might throw NotSupportedException. The Sylvan.Data v0.2.0 library can be used to work around this. You can call the older GetSchemaTable API, then use the Sylvan.Data.Schema type to convert it to the new-style schema IReadOnlyCollection<DbColumn>:

DataTable schemaDT = reader.GetSchemaTable();
var tableSchema = Schema.FromSchemaTable(schemaDT);