从sql server表中检索行显示错误 [英] Retrieving row from sql server table shows error

问题描述

嗨


如果数据存在，我从数据库中检索行它显示正确但表中没有数据显示错误'输入字符串格式不正确'



i我正在使用此代码。

Hi
I am retrieve rows from my database if data is present it shows correct but no data in table the it shows error 'Input string was not in a correct format'

i am using this code.

SqlCommand SqlCmd1 = new SqlCommand("Select SUM(LeaveInDays) from LeaveDetails where StaffId='" + DDLStaffId.Text + "' And Month='" + DDLMonth.Text + "' And Year='" + DDLYear.Text + "'", con);
            con.Open();
            SqlDataReader SqlDr1 = SqlCmd1.ExecuteReader();
            if (SqlDr1.Read())
            {
                NoOfLeaves = Convert.ToInt32(SqlDr1.GetValue(0).ToString());
                txtNoOfLeaves.Text = Convert.ToString(NoOfLeaves);
            }
            SqlDr1.Close();
            con.Close();

推荐答案

使用此int.TryParse（）。

代码如



int NoOfLeaves = 0;

NoOfLeaves = int.TryParse（SqlDr1.GetValue（0）.ToString（），out NoOfLeaves ）？ int.Parse（SqlDr1.GetValue（0）.ToString（））：0;

Use this int.TryParse().
code like

int NoOfLeaves = 0;
NoOfLeaves = int.TryParse(SqlDr1.GetValue(0).ToString(), out NoOfLeaves) ? int.Parse(SqlDr1.GetValue(0).ToString()) : 0;

也许是因为您在表中存储NULL或空值并尝试将它们从代码转换为整数。如果这个假设是正确的，你可以尝试类似：

Maybe because you are storing NULL or blank values in your table and trying to convert them into integer from code. If this assumption is correct, you may try something like:

NoOfLeaves = 0;
if(SqlDr1.GetValue(0) != DBNull.Value && SqlDr1.GetValue(0).ToString() != "")
NoOfLeaves = Convert.ToInt32(SqlDr1.GetValue(0).ToString());
txtNoOfLeaves.Text = Convert.ToString(NoOfLeaves);

NoOfLeaves = Convert.ToInt32（SqlDr1.GetValue（0）.ToString（）） ;



txtNoOfLeaves.Text = Convert.ToString（NoOfLeaves）;



这里查看的价值 NoOfLeaves在转换之前......

NoOfLeaves = Convert.ToInt32(SqlDr1.GetValue(0).ToString());

txtNoOfLeaves.Text = Convert.ToString(NoOfLeaves);

here check the value of "NoOfLeaves" before converting...

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