Filling Dataset by executing query on multiple tables

Your Welcome Mayur..

Your welcome Mayur

Thank You Very Much Sir

In above case when using join, and if the result returned is only one datatable. This datatable your dataset is known by name "resulttable" if i use
a.Fill(ds,"resulttable");
Now, in future you can refer/map to that table by using
ComboBox1.DataSource = ds.Table["resulttable"]
But in case my query itself is returning more than 1 tables, for example
string stmt = "SELECT name FROM Customer
                       SELECT ordernumber FROM Order
                       SELECT recieptnumber FROM RecieveDetails";

Or you might use a stored procedure that returns multiple tables.

Code above will result in 3 DataTables called "Table", "Table1", "Table2" by default if i use -
a.Fill(ds);
ComboBox1.DataSource = ds.Tables["Table"];
ComboBox2.DataSource = ds.Tables["Table1"];
ComboBox3.DataSource = ds.Tables["Table2"];
And it will return 3 datatables called "resulttable", "resulttable1" and "resulttable2" if i use -
a.Fill(ds,"resulttable");
ComboBox1.DataSource = ds.Tables["resulttable"];
ComboBox2.DataSource = ds.Tables["resulttable1"];
ComboBox3.DataSource = ds.Tables["resulttable2"];
Accordingly, you will have to refer these tables by these names only.
But, i recommend you to add a TableMapping for each table returned by your statement.
You can do this as,
SqlDataAdapter da= new SqlDataAdapter(stmt, sqlConnection);
    da.TableMappings.Add("Table", "Customer");
    da.TableMappings.Add("Table1", "Order");
    da.TableMappings.Add("Table2", "RecieveDetails");

    da.Fill(dataset);
Then you can use;

ComboBox1.DataSource = ds.Tables["Customer"];
ComboBox2.DataSource = ds.Tables["Order"];
ComboBox3.DataSource = ds.Tables["RecieveDetails"];
More meaningful... isn't it!
Hope you got this concept...
For more about Table Mapping, you can visit
http://msdn.microsoft.com/en-us/library/ms810286.aspx
Happy Learning...

Sir
Whats This "resulttable". Please give me some  brief exposure,Its Urgent. I didnt understood
Thank You



String query = "SELECT A.firstname FROM
EMPLOYEETABLE AS A
INNER/LEFT/RIGHT/FULL JOIN
ADDRESSTABLE AS B
ON somecondition";
SqlDataAdapter a = new SqlDataAdapter(query,con);
DataSet ds = new DataSet();
a.Fill(ds,"resulttable");
ComboBox1.DataSource = ds;

Why don't you execute a JOIN on multiple tables returning a single dataset.
Example:
String query = "SELECT A.firstname FROM
EMPLOYEETABLE AS A
INNER/LEFT/RIGHT/FULL JOIN
ADDRESSTABLE AS B
ON somecondition";
SqlDataAdapter a = new SqlDataAdapter(query,con);
DataSet ds = new DataSet();
a.Fill(ds,"resulttable");
ComboBox1.DataSource = ds;

Are these tables are related? If these tables are related, data should automatically come in multiple DataTable objects within a singe DataSet. To access a table, you can specify the table name. For example, if you have two tables - Customer and Products.

comboBox1.DataSource = ds.Tables["Customers];

So what you need to do is, either create a relationship in your database and use the JOIN SQL query OR you can add a relationship in the DataRelation (you probably don't need this).

You can achieve your goal using LINQ.
There you can join multiple table and fetch the needed values.
Finally you can fill it in a dataset.