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Fill any ArrayList with SQL query results

I have the following code that accepts an SQL (string) statement, loads the results into an ArrayList (organizationList), which is a collection of organizations:

public void FillDataGridView(DataGridView grid, string SQLCommand)
{
    SqlCommand dataCommand = new SqlCommand();
    dataCommand.Connection = dataConnection;
    dataCommand.CommandType = CommandType.Text;
    dataCommand.CommandText = SQLCommand;

    SqlDataReader dataReader = dataCommand.ExecuteReader();

    while (dataReader.Read())
    {
        Organisation org = new Organisation();

        org.OrganisationId = (int)dataReader["OrganisationId"];
        org.OrganisationName = (string)dataReader["OrganisationName"];

        organisationList.Add(org);
    }

    grid.DataSource = organisationList;
    dataReader.Close();
}

I would like to adapt this method so that I can populate the ArrayList array passed to it.

Is it possible to pass a list to a method and have something like:

public void FillArrayList(DataGridView grid, SqlDataReader reader, ArrayList list)
{
    //Fill the list with the contents of the reader
    while (reader.Read())
    {
        Object  obj = new Object

        for(int i; i = 0; i < obj.NoOfProperties)
        {
            obj.Property[i] = reader[i];
        }

        list.Add(obj);
    }
}

Sorry if this is a little vague, I'm brand new to OOP and a little lost!

Edit: Based on Darren Davis's advice, I changed the method as follows:

public void FillArrayList<T>(DataGridView grid, SqlDataReader reader, List<T> list)
{
    //Fill the list with the contents of the reader
    while (reader.Read())
    {
        Object obj = new Object();
        Type type = typeof(T);

        FieldInfo[] fields = type.GetFields(); // Get the fields of the assembly
        int i = 0;

        foreach(var field in fields)
        {
            field.SetValue(obj, reader[i]); // set the fields of T to the reader value
            // field.setValue(obj, reader[field.Name]); // You can also set the field value to the explicit reader name, i.e. reader["YourProperty"]
            i++;
        }

        list.Add((T)obj);
    }

    grid.DataSource = list;
}

When I run the code, I get an error when I click on an object of type T:

Cannot overlay object of type 'System.Object' on type 'TestHarness.Organisation'.

, . - , ?

,

Andy

+3
4

# 2.0. Generics, ArrayList.

Reflection , :

public void FillArrayList<T>(DataGridView grid, SqlDataReader reader, List<T> list)
{
    //Fill the list with the contents of the reader
    while (reader.Read())
    {
       Object  obj = new Object();
       Type type = typeof(T); // get the type of T (The paramter you passed in, i.e. Organisations)

       FieldInfo[] fields = type.GetFields(); // Get the fields of the assembly
       int i = 0;

        foreach(var field in fields) // Loop round the fields 
        {
            field.setValue(obj, reader[i]); // set the fields of T to the readers value
            // field.setValue(obj, reader[field.Name]); // You can also set the field value to the explicit reader name, i.e. reader["YourProperty"] 
            i++;
        }

        list.Add(obj);
    }
}

:

 FillArrayList(grid, reader, list);

-

 List<Organisations> list = new List<Organisations>();

http://msdn.microsoft.com/en-us/library/ms379564(v=vs.80).aspx

+2

.NET 1.1, , , ArrayList; List<T> .

object - . . . , , dapper:

var list = dataConnection.Query<YourType>(SQLCommand).ToList();

, . YourType ( ), .

4.0, dapper dynamic:

var list = dataConnection.Query(SQLCommand).ToList();

dynamic, ( ):

foreach(var obj in list) {
    Console.WriteLine(obj.OrganisationId);
    Console.WriteLine(obj.OrganisationName);
}

dynamic, , . . , dynamic DataGridView.

, ; , . Dapper :

string foo = ...;
var list = dataConnection.Query<YourType>(
    "select * from SomeTable where Foo = @foo", new { foo }).ToList();
+5

, , ( ).

this. , . .

+1

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