DataAdapter.Fill(Dataset)

Question

i try to get some Data from a Access Database via OleDB in a DataSet. But the DataSet is empty after the Fill() method. The same statement works and return 1 row when i trigger them manually in D*.

OleDbConnection connection = 
   new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Inventar.accdb");
DataSet1 DS = new DataSet1();
connection.Open();

OleDbDataAdapter DBAdapter = new OleDbDataAdapter(
    @"SELECT tbl_Computer.*,  tbl_Besitzer.*
      FROM tbl_Computer 
      INNER JOIN tbl_Besitzer ON tbl_Computer.FK_Benutzer = tbl_Besitzer.ID 
      WHERE (((tbl_Besitzer.Vorname)='ma'));", 
    connection);

DBAdapter.Fill(DS);

Thanks in advance.

New working code:

DataSet ds = new DataSet();
OleDbDataAdapter DBAdapter = new OleDbDataAdapter();

OleDbConnection connection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Inventar.accdb");
string query = @"
    SELECT tbl_Computer.*,  tbl_Besitzer.*
    FROM tbl_Computer 
    INNER JOIN tbl_Besitzer ON tbl_Computer.FK_Benutzer = tbl_Besitzer.ID 
    WHERE (((tbl_Besitzer.Vorname)='ma'));";

connection.Open();

using (OleDbCommand command = new OleDbCommand(query, connection))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(command))
{
    adapter.Fill(ds);
}

Dictionary<string, string> DictValues = new Dictionary<string, string>();

for (int i = 0; i <= ds.Tables[0].Rows[0].ItemArray.Length - 1; i++)
{
    MessageBox.Show(ds.Tables[0].Rows[0].ItemArray[i] + " -- " + ds.Tables[0].Rows[0].Table.Columns[i]);
    DictValues.Add(ds.Tables[0].Rows[0].Table.Columns[i].ToString(), ds.Tables[0].Rows[0].ItemArray[i].ToString());
}

Now The Right code is posted above, with an Dictonary to access the Data more comfortable. hope anybody find help in this post. Thank you all for get it work !

Solution 1

DataSet ds = new DataSet();

using (OleDbConnection connection = new OleDbConnection(connectionString))
using (OleDbCommand command = new OleDbCommand(query, connection))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(command))
{
    adapter.Fill(ds);
}

return ds;

Solution 2

You need to do this:

OleDbConnection connection = new OleDbConnection(
    "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Inventar.accdb");
DataSet DS = new DataSet();
connection.Open();

string query = 
    @"SELECT tbl_Computer.*,  tbl_Besitzer.*
    FROM tbl_Computer 
    INNER JOIN tbl_Besitzer ON tbl_Computer.FK_Benutzer = tbl_Besitzer.ID 
    WHERE (((tbl_Besitzer.Vorname)='ma'))";
OleDbDataAdapter DBAdapter = new OleDbDataAdapter();
DBAdapter.SelectCommand = new OleDbCommand(query, connection); 
DBAdapter.Fill(DS);

By the way, what is this DataSet1? This should be "DataSet".

Comments

[Renatas M.]

Sorry I cant see differences, OleDbDataAdapter constructor takes first parameter as select command text and it is used by SelectCommand. looks like you wrote same thing in different way. Can you explain?

[Akram Shahda]

@abatishchev: That is just a recommendation. Isn't it? Does it solve the problem ??

[abatishchev]

@Akram: If the query is correct, this code will do the work 100%

[Marcus]

i´m with Reniuz, i think the new code brings no changes on logic

[abatishchev]

@User: Please don't propose such edits. Just edit your own post (question)

[Akram Shahda]

@abatishchev: Still not specifying the problem, nor providing a solution for it. I think it is not an answer?

[Marcus]

and how can i get the values ? ds.Tables[0].Rows[0].ItemArray[0] don´t work

[abatishchev]

@User: Do you need only the value of first column in first row?

[Hasan Fahim]

@ Akram Shahda and @Reniuz. The problem is just a typo I think. Rather than writing DataSet, the user had written DataSet1.

[Marcus]

how to get access more comfortable as ds.Tables[0].Rows[0].ItemArray ? in this way the object[] has no Columnnames.

[Hasan Fahim]

@user820831. Do you want to access data from the dataset?

[Marcus]

i need the format same as in the db. i put some code in my question you can have a look it´s alpha :-) hope you can give me a hint

[Hasan Fahim]

To access data, do this ds.Tables[0].Rows[0][0]. This would return the data present in the first row / first column of the first table.

[abatishchev]

@User: I see you call ds.Tables[0].Rows[0] every time. Don't do that; cache instead: var arr = ds.Tables[0].Rows[0].ItemArray and next use just arr

[Marcus]

then use arr[0]["Columnname"] for access ?

[AbcAeffchen]

Your answer should contain an explanation of your code and a description how it solves the problem.

[D M]

DataRow provides strongly typed access via .Field<T>(): int value = arr[0].Field<int>("Columnname");.