ExecuteScalar
in [CSharp]
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From: Dave on 23 Dec 2009 18:13 I need to return a sum of units from a inventory table in code. I'm using a ExecuteScalar statement. I have the following code, OleDbCommand t_command = new OleDbCommand(m_sumstring, connection) connection.Open(); t_command.ExecuteScalar(); I see lots of similar examples but they never show how to actually get the data. So how do I read the value that is returned? int m_data= t_command.ExecuteScalar(); doesn't work.
From: Tom Dacon on 23 Dec 2009 18:26 "Dave" <Dave(a)noWeb.com> wrote in message news:325F62F9-0144-4421-BE19-BE0A982ED304(a)microsoft.com... >I need to return a sum of units from a inventory table in code. I'm using a > ExecuteScalar statement. I have the following code, > > OleDbCommand t_command = new OleDbCommand(m_sumstring, connection) > connection.Open(); > t_command.ExecuteScalar(); > > I see lots of similar examples but they never show how to actually get the > data. So how do I read the value that is returned? > > int m_data= t_command.ExecuteScalar(); > > doesn't work. ExecuteScalar returns Object. Just cast it to whatever data type is appropriate: int m_data = (int)t_command.ExecuteScalar(); Tom Dacon Dacon Software Consulting
From: Scott M. on 23 Dec 2009 22:29 "Dave" <Dave(a)noWeb.com> wrote in message news:325F62F9-0144-4421-BE19-BE0A982ED304(a)microsoft.com... >I need to return a sum of units from a inventory table in code. I'm using a > ExecuteScalar statement. I have the following code, > > OleDbCommand t_command = new OleDbCommand(m_sumstring, connection) > connection.Open(); > t_command.ExecuteScalar(); > > I see lots of similar examples but they never show how to actually get the > data. So how do I read the value that is returned? > > int m_data= t_command.ExecuteScalar(); > > doesn't work. The ExectueScalar method itself does not know that you'll be returning the integer sum of units from an inventory table. It only knows to return the first column from the first record result, which is an Object. You'll need to convert that object to your desired type. in m_data = Convert.ToInt16(t_command.ExecuteScalar()); -Scott
From: Patrice on 24 Dec 2009 06:10 Doesn't work ? That is ? Is this a compile time error because you didn't cast the object ? Also the doc (http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executescalar(VS.80).aspx) almost always a short but usable sample... -- Patrice "Dave" <Dave(a)noWeb.com> a écrit dans le message de news:325F62F9-0144-4421-BE19-BE0A982ED304(a)microsoft.com... >I need to return a sum of units from a inventory table in code. I'm using a > ExecuteScalar statement. I have the following code, > > OleDbCommand t_command = new OleDbCommand(m_sumstring, connection) > connection.Open(); > t_command.ExecuteScalar(); > > I see lots of similar examples but they never show how to actually get the > data. So how do I read the value that is returned? > > int m_data= t_command.ExecuteScalar(); > > doesn't work.
From: Scott M. on 24 Dec 2009 08:14
Oops! Typo, make that: int m_data = Convert.ToInt32(t_command.ExecuteScalar()); -Scott "Scott M." <s-mar(a)nospam.nospam> wrote in message news:%23RZRIkEhKHA.5528(a)TK2MSFTNGP05.phx.gbl... > > "Dave" <Dave(a)noWeb.com> wrote in message > news:325F62F9-0144-4421-BE19-BE0A982ED304(a)microsoft.com... >>I need to return a sum of units from a inventory table in code. I'm using >>a >> ExecuteScalar statement. I have the following code, >> >> OleDbCommand t_command = new OleDbCommand(m_sumstring, connection) >> connection.Open(); >> t_command.ExecuteScalar(); >> >> I see lots of similar examples but they never show how to actually get >> the >> data. So how do I read the value that is returned? >> >> int m_data= t_command.ExecuteScalar(); >> >> doesn't work. > > The ExectueScalar method itself does not know that you'll be returning the > integer sum of units from an inventory table. It only knows to return the > first column from the first record result, which is an Object. > > You'll need to convert that object to your desired type. > > in m_data = Convert.ToInt16(t_command.ExecuteScalar()); > > -Scott > |