Learning foreach...

JollyMansArt

What I would like to do is instead of manually parsing for each table and row. I would like to learn how to do a foreach to dynamically find each table and each row in a database. Here is what I curently have, All I am asking is how to use the foreach command to do this. 1) How would you say: foreach(table in database) then how would you say foreach(row in table) New experimental project I am playing with. I will post back when I find something. Just thought I would ask.

string sConnectString = "Driver={QODBC Driver for QuickBooks};DFQ=C:\\Quickbooks\\sample_company_file.qbw;OpenMode=M;OLE DB Services=-2;";
string sSQL = "SELECT Name FROM Employee";

        OdbcConnection cn;
        OdbcCommand cmd;
        
        //string MyString;
        //MyString="Select \* from Customers";
        //cn = new OdbcConnection("Driver={SQL Server};Server=mySQLServer;UID=sa;PWD=myPassword;Database=Northwind;");
        
        cn = new OdbcConnection(sConnectString);
        cmd =new OdbcCommand(sSQL,cn);
        
        
        //cn.Open();
        //MessageBox.Show("Connected");
        //cn.Close();
        
        try               
           {
              cn.Open();
            MessageBox.Show("open");
            //odbcconnection1.GetSchema("tables")
            //odbcconnection1.GetSchema("columns")
            //http://www.daniweb.com/forums/thread194354.html
            OdbcDataReader dr = cmd.ExecuteReader();

            dr.GetSchemaTable().
            MessageBox.Show(dr.GetSchemaTable().TableName);





           }
        catch (OdbcException ex)
           {
              MessageBox.Show(ex.Message);//<BR/>   There should be no <BR/>
           }
        finally
           {
               cn.Close();
           }

Luc Pattyn

Hi, 1. obviously you get all rows in a table by selecting everything as in "SELECT * FROM tablename", so just skip the WHERE clause. 2. how you get information on the tables themselves probably depends on the database; in MySQL it simply is "SHOW TABLES" Look in the documentation for your database! :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

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OriginalGriff

JollyMansArt wrote:

How would you say: foreach(table in database) then how would you say foreach(row in table)

foreach is not a realy usable construct for examining database tables, I would normally use

        reader = sqlCmd.ExecuteReader();
        while (reader.Read())
            {
            ...
            }

Think about it: if you were dealing with a file, you would say:

string[] lines = inFile.ReadAllLines();
foreach(string s in lines)
{
...
}

rather than trying:

foreach(LineOfText line in inFile)
{
...
}

You can't use foreach for the columns, either - there isn't an Items collection - but even if you could, it really wouldn't be too helpfull:

foreach(var v in reader.Items)
{
... Workout what type it is and what to do with it...
}

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