Imports Microsoft.VisualBasic
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Public Class clsDatabase
Private objConn As SqlConnection
Private objCmd As SqlCommand
Private Trans As SqlTransaction
Private strConnString As String
Public Sub New()
strConnString = System.Configuration.ConfigurationSettings.AppSettings("ConnectionString")
End Sub
Public Function QueryDataReader(ByVal strSQL As String) As SqlDataReader
Dim dtReader As SqlDataReader
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
objCmd = New SqlCommand(strSQL, objConn)
dtReader = objCmd.ExecuteReader()
Return dtReader '*** Return DataReader ***'
End Function
Public Function QueryDataSet(ByVal strSQL As String) As DataSet
Dim ds As New DataSet
Dim dtAdapter As New SqlDataAdapter
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
objCmd = New SqlCommand
With objCmd
.Connection = objConn
.CommandText = strSQL
.CommandType = CommandType.Text
End With
dtAdapter.SelectCommand = objCmd
dtAdapter.Fill(ds)
Return ds '*** Return DataSet ***'
End Function
Public Function QueryDataTable(ByVal strSQL As String) As DataTable
Dim dtAdapter As SqlDataAdapter
Dim dt As New DataTable
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
dtAdapter = New SqlDataAdapter(strSQL, objConn)
dtAdapter.Fill(dt)
Return dt '*** Return DataTable ***'
End Function
Public Function QueryExecuteNonQuery(ByVal strSQL As String) As Boolean
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
Try
objCmd = New SqlCommand()
With objCmd
.Connection = objConn
.CommandType = CommandType.Text
.CommandText = strSQL
End With
objCmd.ExecuteNonQuery()
Return True '*** Return True ***'
Catch ex As Exception
Return False '*** Return False ***'
End Try
End Function
Public Function QueryExecuteScalar(ByVal strSQL As String) As Object
Dim obj As Object
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
Try
objCmd = New SqlCommand()
With objCmd
.Connection = objConn
.CommandType = CommandType.Text
.CommandText = strSQL
End With
obj = objCmd.ExecuteScalar() '*** Return Scalar ***'
Return obj
Catch ex As Exception
Return Nothing '*** Return Nothing ***'
End Try
End Function
Public Function TransStart()
objConn = New SqlConnection
With objConn
.ConnectionString = strConnString
.Open()
End With
Trans = objConn.BeginTransaction(IsolationLevel.ReadCommitted)
End Function
Public Function TransExecute(ByVal strSQL As String) As Boolean
objCmd = New SqlCommand()
With objCmd
.Connection = objConn
.Transaction = Trans
.CommandType = CommandType.Text
.CommandText = strSQL
End With
objCmd.ExecuteNonQuery()
End Function
Public Function TransRollBack()
Trans.Rollback()
End Function
Public Function TransCommit()
Trans.Commit()
End Function
Public Sub Close()
objConn.Close()
objConn = Nothing
End Sub
Load balance : Server 02
