using System.Data.SqlClient; // create connection string to the database string connectionString = "Data Source=myServer;Initial Catalog=myDatabase;Integrated Security=True"; // create SQL command string insertQuery = "INSERT INTO Employees (FirstName, LastName) VALUES (@FirstName, @LastName)"; SqlCommand command = new SqlCommand(insertQuery, new SqlConnection(connectionString)); // add parameters to the command command.Parameters.AddWithValue("@FirstName", "John"); command.Parameters.AddWithValue("@LastName", "Doe"); // open connection and execute command command.Connection.Open(); command.ExecuteNonQuery(); command.Connection.Close();
using System.Data.SqlClient; // create connection string to the database string connectionString = "Data Source=myServer;Initial Catalog=myDatabase;Integrated Security=True"; // create SQL command string selectQuery = "SELECT * FROM Employees WHERE LastName = @LastName"; SqlCommand command = new SqlCommand(selectQuery, new SqlConnection(connectionString)); // add parameter to the command command.Parameters.AddWithValue("@LastName", "Doe"); // open connection, execute command, and read data command.Connection.Open(); SqlDataReader reader = command.ExecuteReader(); while (reader.Read()) { Console.WriteLine("Name: {0} {1}", reader["FirstName"], reader["LastName"]); } reader.Close(); command.Connection.Close();This example creates a SQL command to select data from a table called "Employees". The command uses a parameter to filter by last name. The connection string is defined at the beginning and the command is executed within a try-catch block to handle any exceptions. The data is read using a SqlDataReader object and printed to the console. Overall, the SqlCommand class is useful for executing SQL commands against a SQL Server database and can be used in a variety of scenarios such as inserting, updating, deleting or selecting data. Its package library is System.Data.SqlClient.