如何编写查询 [英] How to Write the query

问题描述

con.Open();
     SqlCommand cmd2 = new SqlCommand("Update diesel set SNO = '" + cb_sno.Text + "',Date = '" + dateTimePicker1.Text + "',Dieselcost = " + textBox1.Text + ",Dieselservice=" + txt_dieselservice.Text + ",Servicetax= " + txt_servicetax.Text + ",Educess = " + txt_educess.Text + ",Addcess = " + txt_addcess.Text + ",Sertax= " + txt_sertaxtot.Text + ",Totbill= " + txt_totbillvalue.Text + ",Flag='" + checkedListBox1.Text + "' where SNO =  " + cb_sno.Text + " and Flag ="TRUE"", con);
   cmd2.ExecuteNonQuery();
   con.Close();

当我插入数据时发生错误.

请帮帮我.

上面是问题所在.

When I inserting data error occurs.

please help me.

from the above what is the problem.

推荐答案

可能是任何东西，从您上面一个文本框中的空格字符开始.
请不要那样做-您会很容易受到SQL注入攻击以及此类问题的影响.请改用参数化查询:

It could be anything, starting from a space character in one of your text boxes on up.
Please don''t do it like that - you leave yourself wide open to an SQL Injection attack as well as to problems like this. Use a parametrized query instead:

SqlCommand cmd2 = new SqlCommand("Update diesel set SNO = @SNO,Date = @DAT,...", con);
cmd2.Parameters.AddWithValue("@SNO", cb_sno.Text);
cmd2.Parameters.AddWithValue("@DAT", dateTimePicker1.Value);
...
cmd2.ExecuteNonQuery();

这也使代码更具可读性.

It also makes the code a whole lot more readable.

请参见代码段和Flag ="TRUE""

在这里，如果您要使用双引号，则应使用\否则将其视为多余的字符串.

Hi,

See the code snippet "and Flag = "TRUE""

Here if you want to use double quote then you should use like \" other wise it will treat as an extra string.

您可以尝试批量更新...
希望此链接可以帮助您...

http://www.jarloo.com/c-bulk-upsert-to-sql -server-tutorial/ [ ^ ]

http://www.java2s.com/Tutorial/CSharp/0560__ADO.Net/BatchUpdateDemo.htm [ ^ ]

http://social.msdn.microsoft.com/Forums/eu/csharplanguage/thread/d0454666-1a7d-4c17-8c96-270b99ca4e4e [

You can try Batch update...
And hope this link can help you...

http://www.jarloo.com/c-bulk-upsert-to-sql-server-tutorial/[^]

http://www.java2s.com/Tutorial/CSharp/0560__ADO.Net/BatchUpdateDemo.htm[^]

http://social.msdn.microsoft.com/Forums/eu/csharplanguage/thread/d0454666-1a7d-4c17-8c96-270b99ca4e4e[^]

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