oprdb.bas

vb+access编写的考试管理系统

Attribute VB_Name = "oprDb"
Public conn As Connection  'conn为连接

Public Sub conntection()
'On Error GoTo dbError
    Set conn = CreateObject("adodb.connection")
    conn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=./data.mdb;Persist Security Info=False"  '打开数据源
    conn.CursorLocation = adUseClient
'dbError:
'    MsgBox "连接数据库时出现错误！"
End Sub

Public Function query(strSql As String) As Recordset
'On Error GoTo dbError
    Dim rs As Recordset
    Set rs = conn.Execute(strSql)
    Set query = rs
'dbError:
'    MsgBox "查询数据时出现错误！"
End Function
Public Function isExist(table As String, value As String, filed As String) As Boolean
    Dim rs As Recordset
    Set rs = query("select * from " + table + " where " + filed + "='" + value + "'")
    Dim n As Integer
    n = getRows(rs)
    rs.Close
    If (n > 0) Then
        isExist = True
    Else
        isExist = False
    End If
End Function


Public Function getRows(rs As Recordset) As Integer
'On Error GoTo dbError
    Dim i As Integer
    i = 0
    While (rs.EOF = False)
        rs.MoveNext
        i = i + 1
    Wend
    getRows = i
'dbError:
'    MsgBox "计算结果集数目时出现错误！"
'    getRows = -1
End Function

Public Function add(strSql As String)
On Error GoTo dbError
    conn.BeginTrans
    conn.Execute (strSql)
    conn.CommitTrans
dbError:
    conn.RollbackTrans
    MsgBox "添加数据时出现错误！"
End Function