class1.vb

这是个用VB编写的机票销售与查询管理系统

Imports System.IO
Imports System.Data
Imports System.Data.SqlClient

Public Class class1

    Public Shared conn As New SqlConnection
    Public Shared cmd As New SqlCommand
    Public Shared da As New SqlDataAdapter
    Public Shared ds As New DataSet
    Public Shared dr As DataRow


    Public Shared Sub init()
        conn.ConnectionString = constr
        cmd.Connection = conn
        da = New SqlDataAdapter
        da.SelectCommand = New SqlCommand
        da.InsertCommand = New SqlCommand
        da.UpdateCommand = New SqlCommand
        da.DeleteCommand = New SqlCommand
        da.SelectCommand.Connection = conn
        da.InsertCommand.Connection = conn
        da.UpdateCommand.Connection = conn
        da.DeleteCommand.Connection = conn
    End Sub

    Public Shared Function query(ByVal SQL As String) As DataSet
        Try
            ds = New DataSet
            da.SelectCommand.CommandText = SQL
            da.Fill(ds)
            Return (ds)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Function

    Public Shared Function insert(ByVal SQL As String) As Integer
        cmd.CommandText = SQL
        conn.Open()
        cmd.ExecuteNonQuery()
        da.SelectCommand = cmd
        conn.Close()
    End Function

    Public Shared Function update(ByVal SQL As String) As Integer
        Try
            Dim i As Integer
            ds = New DataSet
            cmd.CommandText = SQL
            conn.Open()
            i = cmd.ExecuteNonQuery()
            conn.Close()
            da.Fill(ds)
            Return (i)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Function

    Public Shared Function delete(ByVal SQL As String) As Integer
        Dim i As Integer
        ds = New DataSet
        cmd.CommandText = SQL
        conn.Open()
        i = cmd.ExecuteNonQuery()
        conn.Close()
        da.Fill(ds)
        Return (i)
    End Function
End Class