.Net从变量值将NULL值插入SQL Server数据库

using System.Data.SqlClient;

string connectionString = "your_connection_string";
string insertQuery = "INSERT INTO your_table (column1, column2) VALUES (@value1, @value2)";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(insertQuery, connection);
    command.Parameters.AddWithValue("@value1", yourVariable);
    command.Parameters.AddWithValue("@value2", DBNull.Value);

    connection.Open();
    command.ExecuteNonQuery();
}

using System.Data.SqlClient;

string connectionString = "your_connection_string";
string insertQuery = $"INSERT INTO your_table (column1, column2) VALUES ({yourVariable}, NULL)";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(insertQuery, connection);
    connection.Open();
    command.ExecuteNonQuery();
}