dbhandle.bas

财务管理系统的基本功能的实现

Attribute VB_Name = "DbHandle"
Option Explicit
Public DbFinance As New ADODB.Connection  '设置ADODB连接对象的公共变量

Public Function DbConnection()  '打开数据库
    Dim e As ADODB.Error
    
    DbConnection = True 'ConnectDB为真时表示打开数据库无误
    
    On Error GoTo errorhandle '出现任何错误将执行errorhandle进行错误处理
    DbFinance.Errors.Clear
    DbFinance.CommandTimeout = 30  '执行SQL命令的缺省等待时间
    DbFinance.ConnectionTimeout = 30 '连接数据库的缺省时间
    DbFinance.ConnectionString = "DSN=Finance" '打开DSN名为Finance的odbc数据源
    
    On Error GoTo Unconnect '出现数据库连接错误时将进行处理
    DbFinance.Open  '打开数据库
    Exit Function

    
errorhandle:
    If DbFinance.Errors.Count < 1 Then
        MsgBox Err.Description, vbOKOnly + vbExclamation '显示错误描述
    Else
        For Each e In DbFinance.Errors
            MsgBox e.Description    '显示错误描述
        Next e
    End If
    DbConnection = False 'DbConnection为假(False)时表示打开数据库有误
    Set DbFinance = Nothing '关闭错误的数据库
    Exit Function
Unconnect:
    MsgBox "数据库网络连接失败，程序将终止！", vbCritical + vbOKOnly '显示错误描述
    Set DbFinance = Nothing '关闭错误的数据库
    DbConnection = False
    Exit Function
End Function

Public Sub DbClose()  '关闭数据库
On Error Resume Next
    DbFinance.Close
    Set DbFinance = Nothing
End Sub

Public Function resultcount(rs As ADODB.Recordset) As Long      '返回结果集中的记录数
    On Error Resume Next
    resultcount = 0
    Do While rs.EOF = False
        resultcount = resultcount + 1
        rs.MoveNext
    Loop
    rs.MoveFirst
End Function