Why can't use 2 DataReader with same connection

[Heinz_]

That's it, Why can't i use 2 DataReader with same connection? How can i do multiple queries from the same connection. Thanks.

[Colin Angus Mackay]

Heinz_ wrote:

How can i do multiple queries from the same connection

Just open a second identical connection to run the second command.

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[Heinz_]

Hi, i just did it but that second connection is what i have been trying to avoid. I remember that with ADODB in VB6 i was able to do multiple command and reads from the same connection. Thanx, it works this way anyway.

[Colin Angus Mackay]

Heinz_ wrote:

i just did it but that second connection is what i have been trying to avoid.

Why?

Heinz_ wrote:

I remember that with ADODB in VB6 i was able to do multiple command and reads from the same connection.

ADO.NET is not ADODB.

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Scottish Developers events: * .NET debugging, tracing and instrumentation by Duncan Edwards Jones and Code Coverage in .NET by Craig Murphy * Developer Day Scotland: are you interested in speaking or attending? My: Website | Blog

[Ennis Ray Lynch Jr]

If you have a connection you can execute multiple commands on it. Also, keep in mind, that idenctical connection strings will use the connection pool. A man said to the universe: "Sir I exist!" "However," replied the Universe, "The fact has not created in me A sense of obligation." -- Stephen Crane

[Colin Angus Mackay]

Ennis Ray Lynch, Jr. wrote:

If you have a connection you can execute multiple commands on it

But not at the same time, which is what the OP wanted to do.

Ennis Ray Lynch, Jr. wrote:

Also, keep in mind, that idenctical connection strings will use the connection pool.

Absolutely!

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Scottish Developers events: * .NET debugging, tracing and instrumentation by Duncan Edwards Jones and Code Coverage in .NET by Craig Murphy * Developer Day Scotland: are you interested in speaking or attending? My: Website | Blog

[Heinz_]

Understood. I was trying to use only one connection to gain performance but now i replaced the second connection with a subquery in a command of the original connection, check this tasty and parameter rich query: "select SUM(t1.total - COALESCE(t2sum,0)) from ventas as t1 left join (select venta, SUM(cantidad_pagada) as t2sum from pagos_ventas where fecha_pago='" + CDC.Global.SetDBdate(hoy) + "' and metodo_pago<>1 and metodo_pago<>7 group by venta) as t2 on t2.venta=t1.id where t1.nula=0 and t1.pagada=0 and t1.fecha='" + CDC.Global.SetDBdate(hoy) + "'" Bye. -- modified at 15:29 Tuesday 18th July, 2006

[Colin Angus Mackay]

I don't see any parameters in your query - What I do see is lots of SQL Injection that is ripe for attack. A parameter is something like this:

SELECT * FROM Table WHERE something = @Parameter

@Parameter is the parameter. You might like to read about SQL Injection Attacks, what they are, what damage they can do, and most importantly, how to prevent them: http://www.codeproject.com/cs/database/SqlInjectionAttacks.asp[^]

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Scottish Developers events: * .NET debugging, tracing and instrumentation by Duncan Edwards Jones and Code Coverage in .NET by Craig Murphy * Developer Day Scotland: are you interested in speaking or attending? My: Website | Blog

[Heinz_]

Hi, i used the wrong word but you know what i mean, thanks for the link.

[sampathkumarg]

Multiple Active Result Sets (MARS). Probable you need ADO.Net 2.0.