How to return multiple values from a query vb.net - vb.net

Question

one question how to store or return multiple queries result values into multiple variables.. I'm using a query that return 4 columns but how to.. individual store those results into 4 separate variables.. here is my code
Private Sub FrmAlumnos_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
txtCurrentUser.Text = Login.txtUser.Text
Dim strsql As String
strsql = "SELECT ""Agregar"", ""Modificar"", ""Eliminar"", ""Imprimir"" FROM ""Seguridad"".""GrupoPantallas"" WHERE ""IdGrupo"" = (SELECT ""IdGrupo"" FROM ""Seguridad"".""Users"" WHERE ""IdUsers"" = '" _
+ Me.txtCurrentUser.Text + "') AND ""IdPantalla"" = '" + Me.Name + "'"
Try
Using conexion As New Devart.Data.PostgreSql.PgSqlConnection(My.Settings.CNX_Principal)
Dim comando As New Devart.Data.PostgreSql.PgSqlCommand(strsql, conexion)
conexion.Open()
Dim registro As Devart.Data.PostgreSql.PgSqlDataReader = comando.ExecuteReader
If comando.ExecuteReader.Item(0) = 0 Then
btnNew.Visible = False
End If
If comando.ExecuteReader.Item(1) = 0 Then
btnEdit.Visible = False
End If
If comando.ExecuteReader.Item(2) = 0 Then
btnDelete.Visible = False
End If
If comando.ExecuteReader.Item(3) = 0 Then
btnPrint.Visible = False
End If
End Using
Catch ex As Exception
End Try
End Sub
I'm Using PostgreSQL just for you to know...

Answer 1

I think you might find a DataSet to be useful here. Something like:
Dim ds As New DataSet
Dim com As New SqlCommand
com.Connection = <yourconnectionstring>
com.CommandType = CommandType.Text
com.CommandText = "YOURSQLSTUFF"
Dim da As New DataAdapter
da.SelectCommand = com
da.Fill(ds)
ds.Tables(0).TableName = "FirstTable"
ds.Tables(0).PrimaryKey = New DataColumn() {ds.Tables(0).Columns("primaryKeyOfFirstTable")
ds.Tables(1).TableName = "SecondTable"
ds.Tables(1).PrimaryKey = New DataColumn() {ds.Tables(1).Columns("primaryKeyOfSecondTable")
Hope that helps!
-sf
EDIT: After some more searching, I found this link, which might help you out! It's postgreSQL specific!

Answer 2

You need to use the Read method of the DataReader:
Dim strsql As String
strsql = "SELECT ""Agregar"", ""Modificar"", ""Eliminar"", ""Imprimir"" FROM ""Seguridad"".""GrupoPantallas"" WHERE ""IdGrupo"" = (SELECT ""IdGrupo"" FROM ""Seguridad"".""Users"" WHERE ""IdUsers"" = '" _
+ Me.txtCurrentUser.Text + "') AND ""IdPantalla"" = '" + Me.Name + "'"
Try
Using conexion As New Devart.Data.PostgreSql.PgSqlConnection(My.Settings.CNX_Principal)
Dim comando As New Devart.Data.PostgreSql.PgSqlCommand(strsql, conexion)
conexion.Open()
Using registro As Devart.Data.PostgreSql.PgSqlDataReader = comando.ExecuteReader()
//Assuming that there is only a single row returned
If registro.Read()
btnNew.Visible = registro.GetBoolean(0)
btnEdit.Visible = registro.GetBoolean(1)
btnDelete.Visible = registro.GetBoolean(2)
btnPrint.Visible = registro.GetBoolean(3)
End While
End Using
End Using
Catch ex As Exception
End Try
You should also look into using parameters. It would make the code a little cleaner than using a concatenated string and would stop sql injection attacks.

Answer 3

Dim strsql As String
strsql = "SELECT ""Agregar"", ""Modificar"", ""Eliminar"", ""Imprimir"" FROM ""Seguridad"".""GrupoPantallas"" WHERE ""IdGrupo"" = (SELECT ""IdGrupo"" FROM ""Seguridad"".""Users"" WHERE ""IdUsers"" = '" _
+ Me.txtCurrentUser.Text + "') AND ""IdPantalla"" = '" + Me.Name + "'"
Try
Using conexion As New Devart.Data.PostgreSql.PgSqlConnection(My.Settings.CNX_Principal)
Dim comando As New Devart.Data.PostgreSql.PgSqlCommand(strsql, conexion)
conexion.Open()
Dim registro As Devart.Data.PostgreSql.PgSqlDataReader = comando.ExecuteReader
//This is the loop that you missed
While registro.Read()
If comando.ExecuteReader.Item(0) = 0 Then
btnNew.Visible = False
End If
If comando.ExecuteReader.Item(1) = 0 Then
btnEdit.Visible = False
End If
If comando.ExecuteReader.Item(2) = 0 Then
btnDelete.Visible = False
End If
If comando.ExecuteReader.Item(3) = 0 Then
btnPrint.Visible = False
End If
End While
End Using
Catch ex As Exception
End Try
I'm not sure if this is what you're trying to do, but all you have to do is loop through the DataReader as shown above.