在c＃

Question

我的

异常

DataTable ProbRead = SQLData.ExecuteDataSet("SELECT description FROM chk_maintenance_probremark where subheaderid = " + lblrefno.Text.ToString() + " and Type='Problem'").Tables[0];

  

System.IndexOutOfRangeException：找不到表0。

Answer 1

似乎你的SQL查询没有结果 试试这个

var probRead = SQLData.ExecuteDataSet("SELECT description FROM chk_maintenance_probremark where subheaderid = " + lblrefno.Text.ToString() + " and Type='Problem'");
if(probRead.Tables.Count > 0)
{
  var myTable = probRead.Tables[0];
 // do some stuff
}

Answer 2

使查询可读：

//TODO: get rid of hardcoding, but paramterize the query
//DONE: ToString() is redundant in lblrefno.Text
string sql = 
  $@"select Description
       from Chk_Maintenance_ProbRemark
      where SubHeaderId = '{lblrefno.Text}' and
            Type = 'Problem'";

并且您会清楚地看到问题：lblrefno.Text.ToString()应该包含'。

不要忘记测试是否有任何数据返回：

var probRead = SQLData.ExecuteDataSet(sql);

if (probRead.Tables.Count > 0) {
  // It's safe now to call probRead.Tables[0]
  ...
}