各位大大们请帮我分析下错误的原因和位置啊,我个人初步判断错误的根是在adapter.Fill(ds, "dbuser")内,因为去除了这句就没有了错误提示,可是程序也没有用了。苦恼中,谢谢了。
程序如下:protected void Button1_Click(object sender, EventArgs e)
{String cos = "Server=localhost;database=qzs;uid=qzs;pwd=qzs";
SqlConnection co = new SqlConnection(cos); co.Open(); String commandText = "select * from dbuser where username = @username and password = @password "; SqlCommand cm = new SqlCommand(commandText, co); cm.Parameters.Add("@username", SqlDbType.VarChar); cm.Parameters["@username"].Value = Txtname.Text; cm.Parameters.Add("@password", SqlDbType.VarChar); cm.Parameters["@password"].Value = txtpassword.Text;
SqlDataAdapter adapter = new SqlDataAdapter(commandText, co);
DataSet ds = new DataSet(); adapter.Fill(ds, "dbuser");
}点击启动时候没有问题,可是输入用户名和密码,再点登陆的时候跳出了错误。错误提示如下:必须声明变量 '@username'。
说明: 执行当前 Web 请求期间,出现未处理的异常。请检查堆栈跟踪信息,以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.Data.SqlClient.SqlException: 必须声明变量 '@username'。源错误:
行 47: DataSet ds = new DataSet();
行 48:
行 49: adapter.Fill(ds, "dbuser");
行 50:
行 51:
源文件: c:\Inetpub\wwwroot\xuexi\Default.aspx.cs 行: 49 堆栈跟踪:
[SqlException (0x80131904): 必须声明变量 '@username'。]
System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +857418
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +735030
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +188
System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +1838
System.Data.SqlClient.SqlDataReader.ConsumeMetaData() +31
System.Data.SqlClient.SqlDataReader.get_MetaData() +62
System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +297
System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +886
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +132
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +32
System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +122
System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +12
System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior) +7
System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +141
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +137
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable) +83
_Default.Button1_Click(Object sender, EventArgs e) in c:\Inetpub\wwwroot\xuexi\Default.aspx.cs:49
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102
protected void Button1_Click(object sender, EventArgs e)
{
string connectionString= "Server=localhost;database=qzs;uid=qzs;pwd=qzs";
string commandText = "select * from dbuser where username = @username and password = @password ";
SqlDataAdapter sqlAdapter = new SqlDataAdapter(commandText, connectionString);
sqlAdapter.SelectCommand.Parameters.Add("@username", SqlDbType.VarChar, 20).Value = Txtname.Text;//20改成你的长度
sqlAdapter.SelectCommand.Parameters.Add("@password", SqlDbType.VarChar, 20).Value = txtpassword.Text;//20改成你的长度
DataSet ds = new DataSet(); sqlAdapter.Fill(ds, "dbuser");
}
这里的20和你在数据库中的UserName varchar(20) 是一样的!
细心点,自己能搞懂得