OledbParameter问题---“無值提供給一或多個必要參數。”

hz890 2009-01-19 05:03:26



  public DataTable GetDataTable()

    {

        string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Mike\DAOWebTest\App_Data\Northwind.mdb;User Id=;Password=;";

        DataTable dt = new DataTable();

        OleDbConnection conn = new OleDbConnection(connectionString);

        OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=@kind",conn);

        oledbCmd.CommandType = CommandType.Text;

        oledbCmd.Parameters.AddWithValue("@kind", "飲料");

        OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd);

        oledbDa.Fill(dt);

        return dt;

    }

我头一回在ASP.NET中使用OleDb访问Access,不知如何解决此问题，感谢帮助！

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eyuannet 2009-01-20

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string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Mike\\DAOWebTest\\App_Data\\Northwind.mdb;User Id=;Password=;";
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=?",conn);
oledbCmd.CommandType = CommandType.Text;
oledbCmd.Parameters.AddWithValue("kind", "飲料");
OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd);
DataSet ds = new DataSet();
oledbDa.Fill(ds,"Products");
DataTable dt = ds.Tables[0];
return dt;

发表于：2009-01-20 13:58:088楼得分:0
C# code string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Mike\\DAOWebTest\\App_Data\\Northwind.mdb;User Id=;Password=;";
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=?",conn);
oledbCmd.CommandType = CommandType.Text;
oledbCmd.Parameters.AddWithValue("kind", "飲料");
OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd);
DataSet ds = new DataSet();
oledbDa.Fill(ds,"Products");
DataTable dt = ds.Tables[0];
return dt;

用？号

eyuannet 2009-01-20

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        string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Mike\\DAOWebTest\\App_Data\\Northwind.mdb;User Id=;Password=;";

        OleDbConnection conn = new OleDbConnection(connectionString);

        OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=?",conn);

        oledbCmd.CommandType = CommandType.Text;

        oledbCmd.Parameters.AddWithValue("kind", "飲料");

        OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd);

        DataSet ds = new DataSet();

        oledbDa.Fill(ds,"Products");

        DataTable dt = ds.Tables[0];  

        return dt;

用？号

ppp7p 2009-01-19

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你没有给参数赋值.

hz890 2009-01-19

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[Quote=引用 5 楼 wuyq11 的回复:]
OleDbParameter par1 = new OleDbParameter();
par1.ParameterName = "@kind";
par1.Value = "";
cmd.Parameters.Add(par1);

OleDbDataReader dr = cmd.ExecuteReader();
if (dr.Read())
{

}
[/Quote]

还是原来的错误“無值提供給一或多個必要參數。”

wuyq11 2009-01-19

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OleDbParameter par1 = new OleDbParameter();
par1.ParameterName = "@kind";
par1.Value = "";
cmd.Parameters.Add(par1);

OleDbDataReader dr = cmd.ExecuteReader();
if (dr.Read())
{

}

hz890 2009-01-19

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        string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Mike\\DAOWebTest\\App_Data\\Northwind.mdb;User Id=;Password=;";

        OleDbConnection conn = new OleDbConnection(connectionString);

        OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=@kind",conn);

        oledbCmd.CommandType = CommandType.Text;

        oledbCmd.Parameters.AddWithValue("@kind", "飲料");

        OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd);

        DataSet ds = new DataSet();

        oledbDa.Fill(ds,"Products");

        DataTable dt = ds.Tables[0];  

        return dt;

这样做还是发生原先的错误！！！！

hz890 2009-01-19

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[Quote=引用 2 楼 jiang_jiajia10 的回复:]
C# code
public DataTable GetDataTable()
{
string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Mike\DAOWebTest\App_Data\Northwind.mdb;User Id=;Password=;";
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=@kind",conn);
oledbCmd.CommandType = C…
[/Quote]

错误依旧！！！

jiang_jiajia10 2009-01-19

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public DataTable GetDataTable()

    {

        string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Mike\DAOWebTest\App_Data\Northwind.mdb;User Id=;Password=;";

        OleDbConnection conn = new OleDbConnection(connectionString);

        OleDbCommand oledbCmd = new OleDbCommand("select * from Products where [類別]=@kind",conn);

        oledbCmd.CommandType = CommandType.Text;

        oledbCmd.Parameters.AddWithValue("@kind", "飲料");

        OleDbDataAdapter oledbDa = new OleDbDataAdapter(oledbCmd,conn);

        DataSet ds = new DataSet();

        oledbDa.Fill(ds,"Products");

        DataTable dt = ds.Table[0].DefultView;  

        return dt;

    }