ADO.NET工厂模式下数据删除错误

[liuyeede]

代码如下：

       private void DeleteBtn_Click(object sender, EventArgs e)
        {
            //int result = DALClass.DeleteManager(this.managerNameTxt.Text);
            //if (result > -1)
            //{
            //    parent.TaxstatusBar.Panels[0].Text = "删除成功";
            //}
            //else
            //{
            //    parent.TaxstatusBar.Panels[0].Text = "删除失败";
            //}

            int ret =-1;
            string dbProviderName = ConfigurationSettings.AppSettings["DbProviderName"];
            //private static string dbp = "Provider=System.Data.OleDb";
            string dbConnectionString = ConfigurationManager.AppSettings["TaxInvoiceConn"];

            DbProviderFactory dbfactory = DbProviderFactories.GetFactory(dbProviderName);
            DbConnection dbconn = dbfactory.CreateConnection();
            dbconn.ConnectionString = dbConnectionString;

            DbCommand dbCommand = dbconn.CreateCommand();
            dbCommand.CommandText = "Delete From TaxManagers Where MangerNumbuer=@TaxManagerNum";
            dbCommand.CommandType = CommandType.Text;

            DbParameter dbParameter = dbCommand.CreateParameter();
            dbParameter.DbType = DbType.String;
            dbParameter.ParameterName = "@TaxManagerNum";
            dbParameter.Value = this.managerNumTxt.Text;
            dbParameter.Direction = ParameterDirection.Input;
            dbCommand.Parameters.Add(dbParameter);

            dbCommand.Connection.Open();
            ret = dbCommand.ExecuteNonQuery();
            dbCommand.Connection.Close();

            if (ret > -1)
            {
                MessageBox.Show("删除成功");
            }
        }

App.conifg文件内容如下：我用的是Access数据库，驱动是

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="TaxConnectionString"
            connectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Tax.accdb;Persist Security Info=True"
            providerName="System.Data.OleDb" />
      <add name="TaxInvoiceConn" connectionString="Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:\TaxInvionce\TaxInvionce\Tax.mdb"
           providerName="System.Data.OleDb" />
    </connectionStrings>
    
    <appSettings>
        <add key="UseDepartment" value=""/>
        <add key="DepartmentNum" value=""/>
        <add key="DbProviderName" value="System.Data.OleDb"/>
        <add key="TaxInvoiceConn" value="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Tax.accdb;Persist Security Info=True"/>
    </appSettings>
</configuration>

执行到ret = dbCommand.ExecuteNonQuery();时出现如下错误信息：
至少有一个参数未指定

[liuyeede]

顶贴

[辰爸]

提示那个错误是因为dbParameter.Value = this.managerNumTxt.Text，可能没有给@TaxManagerNum成功赋值吧，个人估计！！

[gui0605]

Access数据库中Delete From TaxManagers Where MangerNumbuer=@TaxManagerNum这样用是不对的，参数只能用问号

Delete From TaxManagers Where MangerNumbuer=？

你自己google一下access里面参数的用法

[liuyeede]

资料太少，没有完整的范例

[yagebu1983]

看看你的SQL是否正确。。
最好单步调试。。。

[liuyeede]

至少一个参数没有被指定值。

[gui0605]

string sql="Delete From NewsLink where ID=?"
OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:\DataBase\Temp.mdb");
OleDbCommand cmd = new OleDbCommand(sql,conn); 
OleDbParameter parm = new OleDbParameter("id",OleDbType.Int);
parm.Direction = ParameterDirection.Input;
cmd.Parameters.Add(parm);
cmd.Parameters["id"].Value = 5;
conn.Open();
cmd.ExecuteReader();
conn.Close();

试过，没有问题

[liuyeede]

SQL语句没有问题

[peterb]

Delete From TaxManagers Where MangerNumbuer=?
access数据库中参数占位符是"?",参数名称好像可以随意

[moodboy1982]

问题出在SQL语句上。你打印一下语句看下。

[greenery]

Access和sql server参数语法有点不同
用？代替参数名。

[jieon]

ConnectionString 写错了吧 少了个DSn=xx

[qlzf11140820]

up

[liuyeede]

多谢楼上的朋友,可我用的是DbXXXX的工厂模式....

[panrongzeng]

SQL里面的字段名写错了没？

[mqfwjp]

定

[liuyeede]

字段名没有错，有兴趣的朋友可以试一下ADO.NET下工厂模式的写法。

[bingovox]

int ret =-1;
为什么起名字为ret...我还以为是要返回出此函数的值。。。