DML操作不起作用.

问题描述

你好朋友，


我正在使用Asp.net c#和MYSql作为后端.

我正在更新表，但表没有更新.表中只有3列.
我执行命令对象时也不例外.但是这将从cmd.ExecuteNonQuery()返回0值.
我对此进行了调试，发现 cmd.Parameters 充满了值.
如果我在mysql中手动运行更新命令，它将正常工作.

表格如下
列-数据类型
ShortText-varchar
标题-varchar
id-int

请指导我...

Hello Friends,


I''m using Asp.net c# and MYSql as back-end.

I''m updating a table,but table is not updating.There are only 3 columns in the table.
There is no exception when I''m executing the command object. But this returns 0 value from cmd.ExecuteNonQuery().
I debugged this and found cmd.Parameters are full with values.
and if i manually run the update command in mysql it works fine.

the table is as follow
column -- Datatype
ShortText -- varchar
title -- varchar
id -- int

Please guide me...

int retVal = 0;
        string shortText = ((TextBox)fmvwShortText.FindControl("txtShortText")).Text.Trim();
        try
        {
            int id = Convert.ToInt32(((Label)fmvwShortText.FindControl("lblShrtTextID")).Text);
            MySqlConnection con = new MySqlConnection(System.Configuration.ConfigurationManager.AppSettings["conn"]);
            cmd = new MySqlCommand();
            cmd.Connection = con;
            cmd.CommandText = "UPDATE temp_posts SET ShortText=@shrtText WHERE id=@id AND Title=@title";
            cmd.Parameters.Add("@shrtText", MySqlDbType.VarChar).Value = shortText;
            cmd.Parameters.Add("@title", MySqlDbType.VarChar).Value =Session["EditTitle"].ToString();
            cmd.Parameters.Add("@id", MySqlDbType.Int32).Value = id;
            con.Open();
            retVal = cmd.ExecuteNonQuery();
            con.Close();
        }
        catch (Exception e) { }
        return retVal;

谢谢.

Thanks.

推荐答案

报价:

这从cmd.ExecuteNonQuery(返回0值. ).

this returns 0 value from cmd.ExecuteNonQuery().

cmd.ExecuteNonQuery()

返回更新表后受影响的记录数.由于您的输出为0，表示执行查询后受影响的行数为0.

您必须主要在Where子句中检查Update查询
在

returns number of records affected after updating the table. As your output is 0 means 0 number of rows affected after execution of the query.

You must check your Update query in Where clause mainly
in

Session["EditTitle"].ToString();

中，因为这是一个varchar，它的空格可能与您的可用记录不同.

because this is a varchar it may have spaces which may differ form your available records.

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