Visual Basic .NET Language Data Access Simple Function to read from Database and return as DataTable
Example
This simple function will execute the specified Select SQL command and return the result as data set.
Public Function ReadFromDatabase(ByVal DBConnectionString As String, ByVal SQL As String) As DataTable
Dim dtReturn As New DataTable
Try
'Open the connection using the connection string
Using conn As New SqlClient.SqlConnection(DBConnectionString)
conn.Open()
Using cmd As New SqlClient.SqlCommand()
cmd.Connection = conn
cmd.CommandText = SQL
Dim da As New SqlClient.SqlDataAdapter(cmd)
da.Fill(dtReturn)
End Using
End Using
Catch ex As Exception
'Handle the exception
End Try
'Return the result data set
Return dtReturn
End Function
Now you can execute the above function from below codes
Private Sub MainFunction()
Dim dtCustomers As New DataTable
Dim dtEmployees As New DataTable
Dim dtSuppliers As New DataTable
dtCustomers = ReadFromDatabase("Server=MYDEVPC\SQLEXPRESS;Database=MyDatabase;User Id=sa;Password=pwd22;", "Select * from [Customers]")
dtEmployees = ReadFromDatabase("Server=MYDEVPC\SQLEXPRESS;Database=MyDatabase;User Id=sa;Password=pwd22;", "Select * from [Employees]")
dtSuppliers = ReadFromDatabase("Server=MYDEVPC\SQLEXPRESS;Database=MyDatabase;User Id=sa;Password=pwd22;", "Select * from [Suppliers]")
End Sub
The above example expects that your SQL Express instance "SQLEXPRESS" is currently installed on "MYDEVPC" and your database "MyDatabase" contains "Customers", "Suppliers" and "Employees" tables and the "sa" user password is "pwd22". Please change these values as per your setup to get the desired results.
