Efficient stack usage

[Guest]

Dear NG,

I am making progress processing trees. I can "span" a tree if I make wise
use of the C# stack methods, push() and pop(). What I want to place on the
stack are rows from a data table. The columns (about a dozen) have string,
decimal, and int data in them. The following code concatinates (tab
delimited) a row and places it on the stack sucessfully. Is there any way to
do this without packing and unpacking the columns into and out of a string?
In other words, place the whole row on the stack? Thanks, Bob

private void button1_Click(object sender, System.EventArgs e)
{
SqlConnection mcs3Connection = MCS3_DB.GetConnection();
string selectStmt = "SELECT * FROM ProdStrt WHERE ps_parent = '500-000'
ORDER BY ps_parent";
SqlCommand selectCmd = new SqlCommand(selectStmt, mcs3Connection);
SqlDataAdapter dataAdapter = new SqlDataAdapter(selectCmd);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet, "PS"); //dataSet has 1 DataTable IM
// Moving through a table:
int nRows = dataSet.Tables["PS"].Rows.Count;
string strRows = nRows.ToString();
Stack myStack = new Stack();
string strTemp;
MessageBox.Show("Number of rows: " + strRows);
for (int i = 0; i < nRows; i++)
{
strTemp = dataSet.Tables["PS"].Rows["ps_component"].ToString() + "\t" +
dataSet.Tables["PS"].Rows["ps_parent"].ToString();
myStack.Push(strTemp);
MessageBox.Show("entry: " + strTemp, "Info");
}
for (int i = 0; i < nRows; i++)
{
strTemp = (string) myStack.Pop();
MessageBox.Show("exit: " + strTemp, "Info");
}

}

 

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

I really do not understand what you are trying to do, what a tree has to do
with a datatable or a stack?

if you want to store a "row" in a stack, why dont you get it as a single
field from the DB and just store this value in the stack?

beware that the char you use as column delimiter may appear inside a string
column.

Cheers,

 

[Nicholas Paldino [.NET/C# MVP]]

Robert,

There is no reason why you shouldn't be able to store the DataRow itself
to the stack.

However, what I don't understand is why you don't just use the DataTable
class, and add a new row. Add a column which is a number, and when you add,
populate it with the number of rows currently in the table. Then, when you
pop off the stack, just remove the row at count - 1.

Hope this helps.

 

[Guest]

Hi Nick,

Thank you for the reply. I tried to push(dataSet.Tables["PS"].Rows) on
to the stack, but I recieved an error. Forgot what it was, but if you think
that is the right thing, I will try again. I am not sure what you are
suggesting with your idea to: "just use the DataTable class, and add a new
row. Add a column which is a number, and when you add, populate it with the
number of rows currently in the table."

I need to push and pop certain rows on and off the stack to "span" the tree.
My example does not show the tree processing yet. While I am waiting your
suggestion, I am developing the added processing using the string approach.
Later on I can go for the more efficient method. Thanks for your help. Bob

Robert,

There is no reason why you shouldn't be able to store the DataRow itself
to the stack.

However, what I don't understand is why you don't just use the DataTable
class, and add a new row. Add a column which is a number, and when you add,
populate it with the number of rows currently in the table. Then, when you
pop off the stack, just remove the row at count - 1.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

Dear NG,

I am making progress processing trees. I can "span" a tree if I make wise
use of the C# stack methods, push() and pop(). What I want to place on
the
stack are rows from a data table. The columns (about a dozen) have
string,
decimal, and int data in them. The following code concatinates (tab
delimited) a row and places it on the stack sucessfully. Is there any way
to
do this without packing and unpacking the columns into and out of a
string?
In other words, place the whole row on the stack? Thanks, Bob

private void button1_Click(object sender, System.EventArgs e)
{
SqlConnection mcs3Connection = MCS3_DB.GetConnection();
string selectStmt = "SELECT * FROM ProdStrt WHERE ps_parent = '500-000'
ORDER BY ps_parent";
SqlCommand selectCmd = new SqlCommand(selectStmt, mcs3Connection);
SqlDataAdapter dataAdapter = new SqlDataAdapter(selectCmd);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet, "PS"); //dataSet has 1 DataTable IM
// Moving through a table:
int nRows = dataSet.Tables["PS"].Rows.Count;
string strRows = nRows.ToString();
Stack myStack = new Stack();
string strTemp;
MessageBox.Show("Number of rows: " + strRows);
for (int i = 0; i < nRows; i++)
{
strTemp = dataSet.Tables["PS"].Rows["ps_component"].ToString() + "\t" +
dataSet.Tables["PS"].Rows["ps_parent"].ToString();
myStack.Push(strTemp);
MessageBox.Show("entry: " + strTemp, "Info");
}
for (int i = 0; i < nRows; i++)
{
strTemp = (string) myStack.Pop();
MessageBox.Show("exit: " + strTemp, "Info");
}

}