asp中记录集对象的getrows和getstring用法分析(3)

<% 
' Selected constants from adovbs.inc: 
Const adClipString = 2 

' Declare our variables... always good practice! 
Dim cnnGetString ' ADO connection 
Dim rstGetString ' ADO recordset 
Dim strDBPath ' Path to our Access DB (*.mdb) file 
Dim strDBData ' String that we dump all the data into 
Dim strDBDataTable ' String that we dump all the data into 
' only this time we build a table 
' MapPath to our mdb file's physical path. 
strDBPath = Server.MapPath("db_scratch.mdb") 

' Create a Connection using OLE DB 
Set cnnGetString = Server.CreateObject("ADODB.Connection") 

' This line is for the Access sample database: 
'cnnGetString.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & strDBPath & ";" 
' We're actually using SQL Server so we use this line instead. 
' Comment this line out and uncomment the Access one above to 
' play with the script on your own server. 
cnnGetString.Open "Provider=SQLOLEDB;Data Source=10.2.1.214;" _ 
& "Initial Catalog=samples;User Id=samples;Password=password;" _ 
& "Connect Timeout=15;Network Library=dbmssocn;" 

' Execute a simple query using the connection object. 
' Store the resulting recordset in our variable. 
Set rstGetString = cnnGetString.Execute("Select * FROM scratch") 

' Now this is where it gets interesting... Normally we'd do 
' a loop of some sort until we ran into the last record in 
' in the recordset. This time we're going to get all the data 
' in one fell swoop and dump it into a string so we can 
' disconnect from the DB as quickly as possible. 
strDBData = rstGetString.GetString() 

' Since I'm doing this twice for illustration... I reposition 
' at the beginning of the RS before the second call. 
rstGetString.MoveFirst 

' This time I ask for everything back in HTML table format: 
strDBDataTable = rstGetString.GetString(adClipString, -1, _ 
&"</td><td>", "</td></tr>" & vbCrLf & "<tr><td>", " ") 

' Because of my insatiable desire for neat HTML, I actually 
' truncate the string next. You see, GetString only has 
' a parameter for what goes between rows and not a seperate 
' one for what to place after the last row. Because of the 
' way HTML tables are built, this leaves us with an extra 
' <tr><td> after the last record. GetString places the 
' whole delimiter at the end since it doesn't have anything 
' else to place there and in many situations this works fine. 
' With HTML it's a little bit weird. Most developers simply 
' close the row and move on, but I couldn't bring myself to' 
leave the extra row... especially since it would have a 
' different number of cells then all the others. 
' What can I say... these things tend to bother me. ;) 
strDBDataTable = Left(strDBDataTable, Len(strDBDataTable) - Len("<tr><td>")) 

' Some notes about .GetString: 
' The Method actually takes up to 5 optional arguments: 
' 1. StringFormat - The format in which to return the 
' recordset text. adClipString is the only 
' valid value. 
' 2. NumRows - The number of rows to return. Defaults 
' to -1 indicating all rows. 
' 3. ColumnDelimiter - The text to place in between the columns. 
' Defaults to a tab character 
' 4. RowDelimiter - The text to place in between the rows 
' Defaults to a carriage return 
' 5. NullExpr - Expression to use if a NULL value is 
' returned. Defaults to an empty string. 
' Close our recordset and connection and dispose of the objects. 
' Notice that I'm able to do this before we even worry about 
' displaying any of the data! 
rstGetString.Close 
Set rstGetString = Nothing 
cnnGetString.Close 
Set cnnGetString = Nothing 

' Display the table of the data. I really don't need to do 
' any formatting since the GetString call did most everything 
' for us in terms of building the table text. 
Response.Write "<table border=""1"">" & vbCrLf 
Response.Write "<tr><td>" 
Response.Write strDBDataTable 
Response.Write "</table>" & vbCrLf 
' FYI: Here's the output format you get if you cann GetString 
' without any parameters: 
Response.Write vbCrLf & "<p>Here's the unformatted version:</p>" & vbCrLf 
Response.Write "<pre>" & vbCrLf 
Response.Write strDBDataResponse.Write "</pre>" & vbCrLf 

' That's all folks! 
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