我們在寫asp數據庫程序的時候，通常都會用到SQL語句，而在增加數據和更新數據的時候，通常會使用一下方式：insert into message (incept,sender,title,content,sendtime,flag,issend) values ('"&incept(i)&"','"&membername&"','"&title&"','"&message&"',Now(),0,1) 當字段比較多的時候，而且更新的表比較多的時候，修改起來會比較麻煩，而且查找錯誤也比較困難。使用這個SQL類後可以簡化修改，而且查錯也比較容易。通過類的AddField函數增加字段名和字段值，可輕松的將字段名和字段值插入SQL語句，然後返回該SQL語句。
下面讓我們看看這個類的代碼：
＜%
class SQLString
'************************************
'變量定義
'************************************
'sTableName ---- 表名
'iSQLType ----SQL語句類型：0-增加，1-更新，2-刪除,3-查詢
'sWhere ---- 條件
'sOrder ---- 排序方式
'sSQL ----值
PRivate sTableName,iSQLType,sWhere,sOrder,sSQL
'************************************
'類初始化/結束
'************************************
Private Sub Class_Initialize()
sTableName=""
iSQLType=0
sWhere=""
sOrder=""
sSQL=""
End Sub
Private Sub Class_Terminate()
End Sub
'************************************
'屬性
'************************************
‘設置表名的屬性
Public Property Let TableName(value)
sTableName=value
End Property
‘設置條件
Public Property Let Where(value)
sWhere=value
End Property
‘設置排序方式
Public Property Let Order(value)
sOrder=value
End Property
‘設置查詢語句的類型
Public property Let SQLType(value)
iSQLType=value
select case iSQLType
case 0
sSQL="insert into #0 (#1) values (#2)"
case 1
sSQL="update #0 set #1=#2"
case 2
sSQL="delete from #0 "
case 3
sSQL="select #1 from #0 "
end select
End Property
'************************************
'函數
'************************************
'增加字段（字段名稱，字段值）
Public Sub AddField(sFieldName,sValue)
select case iSQLType
case 0
sSQL=replace(sSQL,"#1",sFieldName & ",#1")
sSQL=replace(sSQL,"#2","'" & sFieldName & "',#2")
case 1
sSQL=replace(sSQL,"#1",sFieldName)
sSQL=replace(sSQL,"#2","'" & sFieldName & "',#1=#2")
case 3
sSQL=replace(sSQL,"#1",sFieldName & ",#1")
End Select
End Sub
'返回SQL語句
Public Function ReturnSQL()
sSQL=replace(sSQL,"#0",sTableName)
select case iSQLType
case 0
sSQL=replace(sSQL,",#1","")
sSQL=replace(sSQL,",#2","")
case 1
sSQL=replace(sSQL,",#1=#2","")
case 3
sSQL=replace(sSQL,",#1","")
end Select
if sWhere＜＞"" then
sSQL=sSQL & " where " & sWhere
end if
if sOrder＜＞"" then
sSQL=sSQL & " order by " & sOrder
end if
ReturnSQL=sSQL
End Function
'清空語句
Public Sub Clear()
sTableName=""
iSQLType=0
sWhere=""
sOrder=""
sSQL=""
End Sub
end class
%＞
使用方法：
例句：insert into message (incept,sender,title,content,sendtime,flag,issend) values ('"&incept(i)&"','"&membername&"','"&title&"','"&message&"',Now(),0,1)
set a =new SQLString ‘創建類對象
a.TableName=" message " ‘設置表名為message
a.SQLType=0 ‘設置查詢類型為增加記錄
a.AddField " incept", incept(i)
a.AddField " sender ", membername
a.AddField " title ", membername
a.AddField " sender ", title
a.AddField " content ", message
a.AddField " sendtime ", sendtime()
a.AddField " flag", 0
a.AddField " issend ", 1
Response.Write a.ReturnSQl
set a=nothing
