我使用 ADO,并且刚接触 C# 该来源显示记录已被读取,无论成功与否。如果找到记录,则效果很好,从不显示 MessageBox.Show("No Records......
public static void readSqlData(String sSource)
{
string strSelection = "SELECT * FROM " + sSource;
SqlDataAdapter da = new SqlDataAdapter(strSelection, cnn);
if (da != null)
{
MessageBox.Show("Records have been read");
dt = new DataTable();
da.Fill(dt);
}
else
{
MessageBox.Show("No records \n" + strSelection);
}
}
我搜索了“测试SqlDataAdapter是否为空”。我不明白这些答案。抱歉,容易混淆。
您必须使用数据适配器填充数据表:
public static void readSqlData(String sSource)
{
string strSelection = "SELECT * FROM " + sSource;
SqlDataAdapter da = new SqlDataAdapter(strSelection, cnn);
DataTable dt = new DataTable();
da.Fill(dt);
if (dt.Rows.Count > 0)
{
MessageBox.Show("Records have been read");
dt = new DataTable();
da.Fill(dt);
}
else
{
MessageBox.Show("No records \n" + strSelection);
}
}