This article describes how to use ado.net to connect to a database and retrieve the columns name from the database table. To do that we create a table in database and using select statement, DataAdapter, Dataset to retrieve the column's name of the table.
Creating connection object
To create a connection we pass the connection string as a parameter in connection object.
Dim str As String = "Data Source=.;uid=sa;pwd=123;database=master"
Dim con As New SqlConnection(str)
The above string defines the connection string which is used to connect the database with the application.
Now we create a database table and insert some values in this table. Table looks like this.
create table logn
(
username varchar(50),
password varchar(40)
)
go
insert into logn values('monu','mohan')
go
insert into logn values('Rohatash','rohit')
go
insert into logn values('Manoj','singh')
go
select * from logn;
The table looks like this.
OUTPUT
For example
The below code define how to retrieve column name from the database table.
Imports System.Data.SqlClient
Module Module1
Sub Main()
Dim str As String = "Data Source=.;uid=sa;pwd=123;database=master"
Dim con As New SqlConnection(str)
Dim str1 As String = "SELECT * FROM logn"
Dim cmd As New SqlCommand(str1, con)
Dim da As New SqlDataAdapter(cmd)
Dim ds As New DataSet()
da.Fill(ds, "logn")
Dim dc As DataColumn
For Each dc In ds.Tables(0).Columns
Console.Write("{0,15}", dc.ColumnName)
Next
Console.WriteLine("")
End Sub
End Module
OUTPUT