SqlServer 连接字串不使用数据库名 实现跨库查询

此次运用需要在同一服务器下，在一个库中SQL查询一组数据，作为参数提交到一个另一个库的函数中进行计算，以前没玩过，问了下度娘，未得到可用结果，遂根据查到的零星信息猜想，取消连接字串里面的库名称试试能不能同时操作多个库，经测试，顺利一次通过运行成功！详见以下代码（以ASP为例）：

Set conn = Server.CreateObject("ADODB.Connection")
SET Rs = Server.CreateObject("ADODB.Recordset")
connstr= "Provider=SQLoledb;data source=.;UID=sa;PWD=youpassword;" '不使用Initial Catalog=DBname"
conn.Open connstr
sql="SELECT * FROM [DBname].[dbo].[TableName] where StationCode ='条件' "
rs.Open sql, conn ,1
If Rs.eof And Rs.bof Then
Response.write "查询 数据错误！"
SID=""
else
Response.write "SO2:" & rs.Fields("SO2").value & "
"
end if

CloseDB 2

sql="DECLARE @SO2_data decimal(20,10),@NO2_data decimal(20,10),@PM10_data decimal(20,10),@CO_data decimal(20,10),@O3_1h_data decimal(20,10),@O3_8h_data decimal(20,10),@PM25_data decimal(20,10),@des varchar(100),@PrimaryPollutant varchar(30),@AQI varchar(10);SELECT @CO_data=convert(decimal(20,10),[CO_24h]),@NO2_data=convert(decimal(20,10),[NO2_24h]),@O3_1h_data=convert(decimal(20,10),[O3_24h]),@O3_8h_data=convert(decimal(20,10),[O3_8h]),@PM10_data=convert(decimal(20,10),[PM10_24h]),@PM25_data=convert(decimal(20,10),[PM2_5_24h]),@SO2_data=convert(decimal(20,10),[SO2_24h]) FROM [ProvincePublishV2].[dbo].[AQIDataPublishLive] where StationCode ='1004A';set @des='PrimaryPollutant';SELECT @PrimaryPollutant=[EnvDataProvince].[dbo].[fn_AQI_Publish] (@SO2_data,@NO2_data,@PM10_data,@CO_data,@O3_1h_data,@O3_8h_data,@PM25_data,@des);set @des='AQI';SELECT @AQI=[EnvDataProvince].[dbo].[fn_AQI_Publish] (@SO2_data,@NO2_data,@PM10_data,@CO_data,@O3_1h_data,@O3_8h_data,@PM25_data,@des);SELECT @PrimaryPollutant as 'PrimaryPollutant' ,@AQI as 'AQI';"
rs.Open sql, conn ,1
If Rs.eof And Rs.bof Then
Response.write "查询AQI错误！"
SID=""
else
Response.write "PrimaryPollutant:" & rs.Fields("PrimaryPollutant").value & ", AQI:" & rs.Fields("AQI").value
end if

CloseDB 1

'----附关闭数据连接子程序--------------------------------
Public Sub CloseDB(allClose)
'1 ,AllClose & Nothing
'0 ,AllClose
'2 ,RS Close
'3 ,RS Close & Nothing
On Error Resume Next
If allClose = 1 Then
If Not RS Is Nothing Then
If RS.State = 1 Then RS.Close
Set RS = Nothing '----------------
End If
If Not conn Is Nothing Then
If conn.State = 1 Then conn.Close
Set conn = Nothing '---------------------
End If
ElseIf allClose = 0 Then
If Not RS Is Nothing Then
If RS.State = 1 Then RS.Close
End If
If Not conn Is Nothing Then
If conn.State = 1 Then conn.Close
End If
ElseIf allClose = 2 Then
If Not RS Is Nothing Then
If RS.State = 1 Then RS.Close
End If
ElseIf allClose = 3 Then
If Not RS Is Nothing Then
If RS.State = 1 Then RS.Close
Set RS = Nothing '--------------
End If
End If
'Response.write "function1 CONN closeed!"
End Sub

里面的 DBname 即为正常连接时需要写在 Initial Catalog= 的库名，这里不写库名的话，在SQL语句中就必须带上库名加上[dbo] 标识再加上表名称来定位到数据表，切记！

即  [DBname].[dbo].[TableName] 

这样，更换了  DBname  后 就可以实现在多个库之间自由查询了。

此记.