How do I extract data from a DataTable?
I have a DataTable
that is filled in from an SQL query to a local database, but I don't know how to extract data from it.
Main method (in test program):
static void Main(string[] args)
{
const string connectionString = "server=localhost\\SQLExpress;database=master;integrated Security=SSPI;";
DataTable table = new DataTable("allPrograms");
using (var conn = new SqlConnection(connectionString))
{
Console.WriteLine("connection created successfuly");
string command = "SELECT * FROM Programs";
using (var cmd = new SqlCommand(command, conn))
{
Console.WriteLine("command created successfuly");
SqlDataAdapter adapt = new SqlDataAdapter(cmd);
conn.Open();
Console.WriteLine("connection opened successfuly");
adapt.Fill(table);
conn.Close();
Console.WriteLine("connection closed successfuly");
}
}
Console.Read();
}
The command I used to create the tables in my database:
create table programs
(
progid int primary key identity(1,1),
name nvarchar(255),
description nvarchar(500),
iconFile nvarchar(255),
installScript nvarchar(255)
)
How can I extract data from the DataTable
into a form meaningful to use?
Solution 1:
The DataTable has a collection .Rows
of DataRow elements.
Each DataRow corresponds to one row in your database, and contains a collection of columns.
In order to access a single value, do something like this:
foreach(DataRow row in YourDataTable.Rows)
{
string name = row["name"].ToString();
string description = row["description"].ToString();
string icoFileName = row["iconFile"].ToString();
string installScript = row["installScript"].ToString();
}
Solution 2:
You can set the datatable as a datasource to many elements.
For eg
gridView
repeater
datalist
etc etc
If you need to extract data from each row then you can use
table.rows[rowindex][columnindex]
or
if you know the column name
table.rows[rowindex][columnname]
If you need to iterate the table then you can either use a for loop or a foreach loop like
for ( int i = 0; i < table.rows.length; i ++ )
{
string name = table.rows[i]["columnname"].ToString();
}
foreach ( DataRow dr in table.Rows )
{
string name = dr["columnname"].ToString();
}