//user_login.cls -->user_login.dll

//Plugin.user_login.F_user
//Plugin.user_login.F_login
//Plugin.user_login.F_select
//Plugin.user_login.F_insert
//Plugin.user_login.F_update 为自定义数据库操作自定义插件
//sqloledb_string = "Provider=SQLOLEDB.1;Password=xxxxxxxx;Persist Security Info=True;User ID=sa;Initial Catalog=Mydbase;Data Source=WIN-2008"

Public Function F_login(sqloledb_string As Variant, select_from As Variant, select_user As Variant, select_password As Variant, String1 As Variant, String2 As Variant) As String
    If String1 = "" Or String2 = "" Then
            F_login = 0
    Else
        Dim db As Connection
        Set db = New Connection
        db.CursorLocation = adUseClient
        db.Open sqloledb_string
        Set rs = New Recordset
        select_string = "select " & select_user & "," & select_password & " from " & select_from & " where " & select_user & " =‘" & String1 & "‘"
        rs.Open select_string, db, adOpenStatic, adLockOptimistic
        Dim i As String
        For t = 0 To Val(rs.RecordCount) - 1
            password = Trim(rs.Fields(select_password).Value)
            rs.MoveNext
        Next t
        If password = String2 Then
            F_login = 1
           Else
            F_login = 0
        End If
        rs.Close
    End If
End Function

‘查询数据
Public Function F_select(sqloledb_string As Variant, select_from As Variant, select_id As Variant, select_field As Variant, String_id As Variant) As String
    F_select = ""
    If select_id <> "" And select_field <> "" Then
        Dim db As Connection
        Set db = New Connection
        db.CursorLocation = adUseClient
        db.Open sqloledb_string
        Set rs = New Recordset
        select_string = "select " & select_field & " from " & select_from & " where " & select_id & " =‘" & String_id & "‘"
        rs.Open select_string, db, adOpenStatic, adLockOptimistic
        mm = Val(rs.RecordCount)
        If mm <> "" Then
            String2 = ""
            For t = 0 To Val(rs.RecordCount) - 1
                String2 = Trim(rs.Fields(select_field).Value) & "|" & String2
                rs.MoveNext
            Next t
            If Val(rs.RecordCount) > 0 Then
                F_select = String2
               Else
                F_select = "0"
            End If
        End If
        rs.Close
    End If
End Function

‘写入数据
Public Function F_update(sqloledb_string As Variant, select_from As Variant, select_id As Variant, update_field As Variant, String_id As Variant, String2 As Variant) As String
    F_update = ""
    If String_id <> "" And String2 <> "" Then
        Dim db As Connection
        Set db = New Connection
        db.CursorLocation = adUseClient
        db.Open sqloledb_string
        Set rs = New Recordset
        select_string = "select " & select_id & " from " & select_from & " where " & select_id & " =‘" & String_id & "‘"
        rs.Open select_string, db, adOpenStatic, adLockOptimistic
        Dim mm
        mm = Val(rs.RecordCount)
        If mm <> "" Then
            If mm > 0 Then
               update_string = "update " & select_from & " set " & update_field & "= ‘" & String2 & "‘  where " & select_id & "=‘" & String_id & "‘ "
    ‘           MsgBox (update_string)
               db.Execute update_string
                F_update = "1"
            Else
                F_update = "0"
            End If
        End If
        rs.Close
    End If
End Function

‘加入数据
Public Function F_insert(sqloledb_string As Variant, select_from As Variant, insert_field As Variant, String1 As Variant) As String
    F_insert = ""
    If insert_field <> "" And String1 <> "" Then
        Dim db As Connection
        Set db = New Connection
        db.CursorLocation = adUseClient
        db.Open sqloledb_string
        Set rs = New Recordset
        select_string = "select * from " & select_from & " where " & insert_field & " =‘" & String1 & "‘"
        rs.Open select_string, db, adOpenStatic, adLockOptimistic
        Dim mm
        mm = Val(rs.RecordCount)
‘        MsgBox mm
        If mm <> "" Then
            If mm = 0 Then
               insert_string = "insert  " & select_from & " ( " & insert_field & " )  select ‘" & String1 & "‘"
‘               MsgBox (insert_string)
               db.Execute insert_string
                F_insert = "1"
               Else
                F_insert = "0"
            End If
        End If
        rs.Close
    End If
End Function

Q语言 自定义插件实例（VB6.0数据库操作函数）