c# 和access 语句，可以帮我每行都解释一下吗？小弟不太懂

Question

if (textbox1.Text != "" && textbox2.Text != "")
{
string sql = "select * from [user] where ID=" + textbox1.Text + " and [password]='" + textbox2.Text + "'";
adapter = new OleDbDataAdapter(sql, str);
OleDbCommandBuilder buider = new OleDbCommandBuilder(adapter);
adapter.InsertCommand = buider.GetInsertCommand();
table.Clear();
adapter.Fill(table);
if (table.Rows.Count > 0)
{
}
else
{
MessageBox.Show("用户名或密码不能空");
}

Answer 1

if (textbox1.Text != "" && textbox2.Text != "")
{
string sql = "select * from [user] where ID=" + textbox1.Text + " and [password]='" + textbox2.Text + "'";//定义sql语句
adapter = new OleDbDataAdapter(sql, str);//创建adapter
OleDbCommandBuilder buider = new OleDbCommandBuilder(adapter);//创建command
adapter.InsertCommand = buider.GetInsertCommand();//设置进行插入操作的command
table.Clear();//清空已有的table
adapter.Fill(table);//根据sql填充table
if (table.Rows.Count > 0)//如果记录数大于0
{
}
else
{
MessageBox.Show("用户名或密码不能空");
}