|
dev
newsgroups
|
|||||||||||||||||||||||
|
|||||||||||||||||||||||
DataReader - RowsAffected propertyWhy and how is this property used?
Documentation says it is number of rows changed, inserted, deleted and can only be used after the DataReader is closed. I thought the DataReader was for forward read only access...so how can there be rows changed/inserted/deleted? TIA John John,
In Net1.0 and 1.1 you can only have one open connection at a time this will change in 2.0. I hope this helps, Cor Hi Cor,
Sorry but I dont understand what the number of connections has to do with the RowsAffected property. John On Sun, 27 Mar 2005 10:05:01 +0200, "Cor Ligthert" <notmyfirstn***@planet.nl> wrote: Show quote >John, > >In Net1.0 and 1.1 you can only have one open connection at a time this will >change in 2.0. > >I hope this helps, > >Cor > JL,
> Sorry but I dont understand what the number of connections has to do Maybe I don't understand you however how will you do a update when the > with the RowsAffected property. > datatreader is still open (with its connection) and you use for the update a connection and the command.executenonquery? Cor JL,
A DataReader is the result of a DbCommand.ExecuteReader. Now the DbCommand might have any command text - say a batched SQL command that might contain both inserts and updates. RecordsAffected will help you get information out of those. You might ask "Why in the world would I want to batch my select statement with an insert statement" Well say if you inserted a row, and now you wish to retreive the latest generated identity value, you could have code that looks somewhat like this. private const string CONN_STR = "Server=(local);Database=Test;Integrated Security=SSPI"; static void Main(string[] args) { using (SqlConnection conn = new SqlConnection(CONN_STR)) { SqlCommand cmd = conn.CreateCommand(); cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); Select * from Animals"; conn.Open(); SqlDataReader rdr = cmd.ExecuteReader(); while (rdr.Read()) { Console.WriteLine(rdr.RecordsAffected); System.Diagnostics.Debugger.Break(); } } } ... Obviously (before anyone corrects me), the better way to retreive identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to make a point here :-) All this is explained in my upcoming book on ADO.NET 2.0 and more !! - Sahil Malik http://codebetter.com/blogs/sahil.malik/ Show quote "J L" <j***@marymonte.com> wrote in message news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... > Why and how is this property used? > > Documentation says it is number of rows changed, inserted, deleted and > can only be used after the DataReader is closed. I thought the > DataReader was for forward read only access...so how can there be rows > changed/inserted/deleted? > > TIA > John > I see your point. Good example.
One minor question...the doc says the RowsAffected is not available until the reader is closed. So in your example, would you move the writeline reference outside the loop and close the reader first? John On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" <contactmethrumyblog@nospam.com> wrote: Show quote >JL, > >A DataReader is the result of a DbCommand.ExecuteReader. >Now the DbCommand might have any command text - say a batched SQL command >that might contain both inserts and updates. RecordsAffected will help you >get information out of those. > >You might ask "Why in the world would I want to batch my select statement >with an insert statement" >Well say if you inserted a row, and now you wish to retreive the latest >generated identity value, you could have code that looks somewhat like this. > >private const string CONN_STR = "Server=(local);Database=Test;Integrated >Security=SSPI"; >static void Main(string[] args) >{ >using (SqlConnection conn = new SqlConnection(CONN_STR)) >{ >SqlCommand cmd = conn.CreateCommand(); >cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); >Select * from Animals"; >conn.Open(); >SqlDataReader rdr = cmd.ExecuteReader(); >while (rdr.Read()) >{ >Console.WriteLine(rdr.RecordsAffected); >System.Diagnostics.Debugger.Break(); >} >} >} >.. Obviously (before anyone corrects me), the better way to retreive >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to make a >point here :-) >All this is explained in my upcoming book on ADO.NET 2.0 and more !! > >- Sahil Malik >http://codebetter.com/blogs/sahil.malik/ > > > > > >"J L" <j***@marymonte.com> wrote in message >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... >> Why and how is this property used? >> >> Documentation says it is number of rows changed, inserted, deleted and >> can only be used after the DataReader is closed. I thought the >> DataReader was for forward read only access...so how can there be rows >> changed/inserted/deleted? >> >> TIA >> John >> > Man ru serious? I mean .. it depends. If your batched statement looks like
this. Insert ; Select. Then RecordsAffected should be available before .. you can actually simply copy paste my example and run it and find out for yourself. - Sahil Malik http://codebetter.com/blogs/sahil.malik/ Show quote "J L" <j***@marymonte.com> wrote in message news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... > I see your point. Good example. > > One minor question...the doc says the RowsAffected is not available > until the reader is closed. So in your example, would you move the > writeline reference outside the loop and close the reader first? > > John > > > On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" > <contactmethrumyblog@nospam.com> wrote: > > >JL, > > > >A DataReader is the result of a DbCommand.ExecuteReader. > >Now the DbCommand might have any command text - say a batched SQL command > >that might contain both inserts and updates. RecordsAffected will help you > >get information out of those. > > > >You might ask "Why in the world would I want to batch my select statement > >with an insert statement" > >Well say if you inserted a row, and now you wish to retreive the latest > >generated identity value, you could have code that looks somewhat like this. > > > >private const string CONN_STR = "Server=(local);Database=Test;Integrated > >Security=SSPI"; > >static void Main(string[] args) > >{ > >using (SqlConnection conn = new SqlConnection(CONN_STR)) > >{ > >SqlCommand cmd = conn.CreateCommand(); > >cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); > >Select * from Animals"; > >conn.Open(); > >SqlDataReader rdr = cmd.ExecuteReader(); > >while (rdr.Read()) > >{ > >Console.WriteLine(rdr.RecordsAffected); > >System.Diagnostics.Debugger.Break(); > >} > >} > >} > >.. Obviously (before anyone corrects me), the better way to retreive > >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to make a > >point here :-) > >All this is explained in my upcoming book on ADO.NET 2.0 and more !! > > > >- Sahil Malik > >http://codebetter.com/blogs/sahil.malik/ > > > > > > > > > > > >"J L" <j***@marymonte.com> wrote in message > >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... > >> Why and how is this property used? > >> > >> Documentation says it is number of rows changed, inserted, deleted and > >> can only be used after the DataReader is closed. I thought the > >> DataReader was for forward read only access...so how can there be rows > >> changed/inserted/deleted? > >> > >> TIA > >> John > >> > > > I did try but can not get the query to work. I get a "Characters found
after end of SQL statement" error when I try the combined SQL of Insert and Select. Individually they work fine and I just concatenate them with an ; between. If you have time, please advise why I get this error. My exact SQL is: INSERT INTO Operators (OperatorID, OperatorName) VALUES ('12345', 'John'); SELECT * FROM Operators; Thanks, John On Mon, 28 Mar 2005 10:26:02 -0500, "Sahil Malik" <contactmethrumyblog@nospam.com> wrote: Show quote >Man ru serious? I mean .. it depends. If your batched statement looks like >this. > >Insert ; Select. > >Then RecordsAffected should be available before .. you can actually simply >copy paste my example and run it and find out for yourself. > >- Sahil Malik >http://codebetter.com/blogs/sahil.malik/ > > > >"J L" <j***@marymonte.com> wrote in message >news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... >> I see your point. Good example. >> >> One minor question...the doc says the RowsAffected is not available >> until the reader is closed. So in your example, would you move the >> writeline reference outside the loop and close the reader first? >> >> John >> >> >> On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" >> <contactmethrumyblog@nospam.com> wrote: >> >> >JL, >> > >> >A DataReader is the result of a DbCommand.ExecuteReader. >> >Now the DbCommand might have any command text - say a batched SQL command >> >that might contain both inserts and updates. RecordsAffected will help >you >> >get information out of those. >> > >> >You might ask "Why in the world would I want to batch my select statement >> >with an insert statement" >> >Well say if you inserted a row, and now you wish to retreive the latest >> >generated identity value, you could have code that looks somewhat like >this. >> > >> >private const string CONN_STR = "Server=(local);Database=Test;Integrated >> >Security=SSPI"; >> >static void Main(string[] args) >> >{ >> >using (SqlConnection conn = new SqlConnection(CONN_STR)) >> >{ >> >SqlCommand cmd = conn.CreateCommand(); >> >cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); >> >Select * from Animals"; >> >conn.Open(); >> >SqlDataReader rdr = cmd.ExecuteReader(); >> >while (rdr.Read()) >> >{ >> >Console.WriteLine(rdr.RecordsAffected); >> >System.Diagnostics.Debugger.Break(); >> >} >> >} >> >} >> >.. Obviously (before anyone corrects me), the better way to retreive >> >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to make a >> >point here :-) >> >All this is explained in my upcoming book on ADO.NET 2.0 and more !! >> > >> >- Sahil Malik >> >http://codebetter.com/blogs/sahil.malik/ >> > >> > >> > >> > >> > >> >"J L" <j***@marymonte.com> wrote in message >> >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... >> >> Why and how is this property used? >> >> >> >> Documentation says it is number of rows changed, inserted, deleted and >> >> can only be used after the DataReader is closed. I thought the >> >> DataReader was for forward read only access...so how can there be rows >> >> changed/inserted/deleted? >> >> >> >> TIA >> >> John >> >> >> > >> > Hmm .. I tried that in .NET 2.0.
Let me try that in .NET 1.1 later tonight and get back at you? - Sahil Malik http://codebetter.com/blogs/sahil.malik/ Show quote "J L" <j***@marymonte.com> wrote in message "Server=(local);Database=Test;Integratednews:iujg41t65iup4ig6si03o85q9otgagi6ob@4ax.com... > I did try but can not get the query to work. I get a "Characters found > after end of SQL statement" error when I try the combined SQL of > Insert and Select. Individually they work fine and I just concatenate > them with an ; between. If you have time, please advise why I get this > error. > > My exact SQL is: > > INSERT INTO Operators (OperatorID, OperatorName) VALUES ('12345', > 'John'); SELECT * FROM Operators; > > Thanks, > John > On Mon, 28 Mar 2005 10:26:02 -0500, "Sahil Malik" > <contactmethrumyblog@nospam.com> wrote: > > >Man ru serious? I mean .. it depends. If your batched statement looks like > >this. > > > >Insert ; Select. > > > >Then RecordsAffected should be available before .. you can actually simply > >copy paste my example and run it and find out for yourself. > > > >- Sahil Malik > >http://codebetter.com/blogs/sahil.malik/ > > > > > > > >"J L" <j***@marymonte.com> wrote in message > >news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... > >> I see your point. Good example. > >> > >> One minor question...the doc says the RowsAffected is not available > >> until the reader is closed. So in your example, would you move the > >> writeline reference outside the loop and close the reader first? > >> > >> John > >> > >> > >> On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" > >> <contactmethrumyblog@nospam.com> wrote: > >> > >> >JL, > >> > > >> >A DataReader is the result of a DbCommand.ExecuteReader. > >> >Now the DbCommand might have any command text - say a batched SQL command > >> >that might contain both inserts and updates. RecordsAffected will help > >you > >> >get information out of those. > >> > > >> >You might ask "Why in the world would I want to batch my select statement > >> >with an insert statement" > >> >Well say if you inserted a row, and now you wish to retreive the latest > >> >generated identity value, you could have code that looks somewhat like > >this. > >> > > >> >private const string CONN_STR = Show quote > >> >Security=SSPI"; > >> >static void Main(string[] args) > >> >{ > >> >using (SqlConnection conn = new SqlConnection(CONN_STR)) > >> >{ > >> >SqlCommand cmd = conn.CreateCommand(); > >> >cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); > >> >Select * from Animals"; > >> >conn.Open(); > >> >SqlDataReader rdr = cmd.ExecuteReader(); > >> >while (rdr.Read()) > >> >{ > >> >Console.WriteLine(rdr.RecordsAffected); > >> >System.Diagnostics.Debugger.Break(); > >> >} > >> >} > >> >} > >> >.. Obviously (before anyone corrects me), the better way to retreive > >> >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to make a > >> >point here :-) > >> >All this is explained in my upcoming book on ADO.NET 2.0 and more !! > >> > > >> >- Sahil Malik > >> >http://codebetter.com/blogs/sahil.malik/ > >> > > >> > > >> > > >> > > >> > > >> >"J L" <j***@marymonte.com> wrote in message > >> >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... > >> >> Why and how is this property used? > >> >> > >> >> Documentation says it is number of rows changed, inserted, deleted and > >> >> can only be used after the DataReader is closed. I thought the > >> >> DataReader was for forward read only access...so how can there be rows > >> >> changed/inserted/deleted? > >> >> > >> >> TIA > >> >> John > >> >> > >> > > >> > > > That would be great. Thanks.
John On Mon, 28 Mar 2005 14:42:09 -0500, "Sahil Malik" <contactmethrumyblog@nospam.com> wrote: Show quote >Hmm .. I tried that in .NET 2.0. > >Let me try that in .NET 1.1 later tonight and get back at you? > > >- Sahil Malik >http://codebetter.com/blogs/sahil.malik/ > > > >"J L" <j***@marymonte.com> wrote in message >news:iujg41t65iup4ig6si03o85q9otgagi6ob@4ax.com... >> I did try but can not get the query to work. I get a "Characters found >> after end of SQL statement" error when I try the combined SQL of >> Insert and Select. Individually they work fine and I just concatenate >> them with an ; between. If you have time, please advise why I get this >> error. >> >> My exact SQL is: >> >> INSERT INTO Operators (OperatorID, OperatorName) VALUES ('12345', >> 'John'); SELECT * FROM Operators; >> >> Thanks, >> John >> On Mon, 28 Mar 2005 10:26:02 -0500, "Sahil Malik" >> <contactmethrumyblog@nospam.com> wrote: >> >> >Man ru serious? I mean .. it depends. If your batched statement looks >like >> >this. >> > >> >Insert ; Select. >> > >> >Then RecordsAffected should be available before .. you can actually >simply >> >copy paste my example and run it and find out for yourself. >> > >> >- Sahil Malik >> >http://codebetter.com/blogs/sahil.malik/ >> > >> > >> > >> >"J L" <j***@marymonte.com> wrote in message >> >news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... >> >> I see your point. Good example. >> >> >> >> One minor question...the doc says the RowsAffected is not available >> >> until the reader is closed. So in your example, would you move the >> >> writeline reference outside the loop and close the reader first? >> >> >> >> John >> >> >> >> >> >> On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" >> >> <contactmethrumyblog@nospam.com> wrote: >> >> >> >> >JL, >> >> > >> >> >A DataReader is the result of a DbCommand.ExecuteReader. >> >> >Now the DbCommand might have any command text - say a batched SQL >command >> >> >that might contain both inserts and updates. RecordsAffected will help >> >you >> >> >get information out of those. >> >> > >> >> >You might ask "Why in the world would I want to batch my select >statement >> >> >with an insert statement" >> >> >Well say if you inserted a row, and now you wish to retreive the >latest >> >> >generated identity value, you could have code that looks somewhat like >> >this. >> >> > >> >> >private const string CONN_STR = >"Server=(local);Database=Test;Integrated >> >> >Security=SSPI"; >> >> >static void Main(string[] args) >> >> >{ >> >> >using (SqlConnection conn = new SqlConnection(CONN_STR)) >> >> >{ >> >> >SqlCommand cmd = conn.CreateCommand(); >> >> >cmd.CommandText = "Insert into Animals (AnimalType) values ('Parrot'); >> >> >Select * from Animals"; >> >> >conn.Open(); >> >> >SqlDataReader rdr = cmd.ExecuteReader(); >> >> >while (rdr.Read()) >> >> >{ >> >> >Console.WriteLine(rdr.RecordsAffected); >> >> >System.Diagnostics.Debugger.Break(); >> >> >} >> >> >} >> >> >} >> >> >.. Obviously (before anyone corrects me), the better way to retreive >> >> >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to >make a >> >> >point here :-) >> >> >All this is explained in my upcoming book on ADO.NET 2.0 and more !! >> >> > >> >> >- Sahil Malik >> >> >http://codebetter.com/blogs/sahil.malik/ >> >> > >> >> > >> >> > >> >> > >> >> > >> >> >"J L" <j***@marymonte.com> wrote in message >> >> >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... >> >> >> Why and how is this property used? >> >> >> >> >> >> Documentation says it is number of rows changed, inserted, deleted >and >> >> >> can only be used after the DataReader is closed. I thought the >> >> >> DataReader was for forward read only access...so how can there be >rows >> >> >> changed/inserted/deleted? >> >> >> >> >> >> TIA >> >> >> John >> >> >> >> >> > >> >> >> > >> > Confirmed. .NET 1.1 behavior is different from 2.0.
- Sahil Malik http://codebetter.com/blogs/sahil.malik/ Show quote "J L" <j***@marymonte.com> wrote in message news:v1og41h5q3rngunohirrdntg3m5torpfmt@4ax.com... > That would be great. Thanks. > > John > > On Mon, 28 Mar 2005 14:42:09 -0500, "Sahil Malik" > <contactmethrumyblog@nospam.com> wrote: > >>Hmm .. I tried that in .NET 2.0. >> >>Let me try that in .NET 1.1 later tonight and get back at you? >> >> >>- Sahil Malik >>http://codebetter.com/blogs/sahil.malik/ >> >> >> >>"J L" <j***@marymonte.com> wrote in message >>news:iujg41t65iup4ig6si03o85q9otgagi6ob@4ax.com... >>> I did try but can not get the query to work. I get a "Characters found >>> after end of SQL statement" error when I try the combined SQL of >>> Insert and Select. Individually they work fine and I just concatenate >>> them with an ; between. If you have time, please advise why I get this >>> error. >>> >>> My exact SQL is: >>> >>> INSERT INTO Operators (OperatorID, OperatorName) VALUES ('12345', >>> 'John'); SELECT * FROM Operators; >>> >>> Thanks, >>> John >>> On Mon, 28 Mar 2005 10:26:02 -0500, "Sahil Malik" >>> <contactmethrumyblog@nospam.com> wrote: >>> >>> >Man ru serious? I mean .. it depends. If your batched statement looks >>like >>> >this. >>> > >>> >Insert ; Select. >>> > >>> >Then RecordsAffected should be available before .. you can actually >>simply >>> >copy paste my example and run it and find out for yourself. >>> > >>> >- Sahil Malik >>> >http://codebetter.com/blogs/sahil.malik/ >>> > >>> > >>> > >>> >"J L" <j***@marymonte.com> wrote in message >>> >news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... >>> >> I see your point. Good example. >>> >> >>> >> One minor question...the doc says the RowsAffected is not available >>> >> until the reader is closed. So in your example, would you move the >>> >> writeline reference outside the loop and close the reader first? >>> >> >>> >> John >>> >> >>> >> >>> >> On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" >>> >> <contactmethrumyblog@nospam.com> wrote: >>> >> >>> >> >JL, >>> >> > >>> >> >A DataReader is the result of a DbCommand.ExecuteReader. >>> >> >Now the DbCommand might have any command text - say a batched SQL >>command >>> >> >that might contain both inserts and updates. RecordsAffected will >>> >> >help >>> >you >>> >> >get information out of those. >>> >> > >>> >> >You might ask "Why in the world would I want to batch my select >>statement >>> >> >with an insert statement" >>> >> >Well say if you inserted a row, and now you wish to retreive the >>latest >>> >> >generated identity value, you could have code that looks somewhat >>> >> >like >>> >this. >>> >> > >>> >> >private const string CONN_STR = >>"Server=(local);Database=Test;Integrated >>> >> >Security=SSPI"; >>> >> >static void Main(string[] args) >>> >> >{ >>> >> >using (SqlConnection conn = new SqlConnection(CONN_STR)) >>> >> >{ >>> >> >SqlCommand cmd = conn.CreateCommand(); >>> >> >cmd.CommandText = "Insert into Animals (AnimalType) values >>> >> >('Parrot'); >>> >> >Select * from Animals"; >>> >> >conn.Open(); >>> >> >SqlDataReader rdr = cmd.ExecuteReader(); >>> >> >while (rdr.Read()) >>> >> >{ >>> >> >Console.WriteLine(rdr.RecordsAffected); >>> >> >System.Diagnostics.Debugger.Break(); >>> >> >} >>> >> >} >>> >> >} >>> >> >.. Obviously (before anyone corrects me), the better way to retreive >>> >> >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to >>make a >>> >> >point here :-) >>> >> >All this is explained in my upcoming book on ADO.NET 2.0 and more !! >>> >> > >>> >> >- Sahil Malik >>> >> >http://codebetter.com/blogs/sahil.malik/ >>> >> > >>> >> > >>> >> > >>> >> > >>> >> > >>> >> >"J L" <j***@marymonte.com> wrote in message >>> >> >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... >>> >> >> Why and how is this property used? >>> >> >> >>> >> >> Documentation says it is number of rows changed, inserted, deleted >>and >>> >> >> can only be used after the DataReader is closed. I thought the >>> >> >> DataReader was for forward read only access...so how can there be >>rows >>> >> >> changed/inserted/deleted? >>> >> >> >>> >> >> TIA >>> >> >> John >>> >> >> >>> >> > >>> >> >>> > >>> >> > Thanks Sahil...good to know.
John On Fri, 1 Apr 2005 01:40:15 -0500, "Sahil Malik" <contactmethrumyblog@nospam.com> wrote: Show quote >Confirmed. .NET 1.1 behavior is different from 2.0. > >- Sahil Malik >http://codebetter.com/blogs/sahil.malik/ > > >"J L" <j***@marymonte.com> wrote in message >news:v1og41h5q3rngunohirrdntg3m5torpfmt@4ax.com... >> That would be great. Thanks. >> >> John >> >> On Mon, 28 Mar 2005 14:42:09 -0500, "Sahil Malik" >> <contactmethrumyblog@nospam.com> wrote: >> >>>Hmm .. I tried that in .NET 2.0. >>> >>>Let me try that in .NET 1.1 later tonight and get back at you? >>> >>> >>>- Sahil Malik >>>http://codebetter.com/blogs/sahil.malik/ >>> >>> >>> >>>"J L" <j***@marymonte.com> wrote in message >>>news:iujg41t65iup4ig6si03o85q9otgagi6ob@4ax.com... >>>> I did try but can not get the query to work. I get a "Characters found >>>> after end of SQL statement" error when I try the combined SQL of >>>> Insert and Select. Individually they work fine and I just concatenate >>>> them with an ; between. If you have time, please advise why I get this >>>> error. >>>> >>>> My exact SQL is: >>>> >>>> INSERT INTO Operators (OperatorID, OperatorName) VALUES ('12345', >>>> 'John'); SELECT * FROM Operators; >>>> >>>> Thanks, >>>> John >>>> On Mon, 28 Mar 2005 10:26:02 -0500, "Sahil Malik" >>>> <contactmethrumyblog@nospam.com> wrote: >>>> >>>> >Man ru serious? I mean .. it depends. If your batched statement looks >>>like >>>> >this. >>>> > >>>> >Insert ; Select. >>>> > >>>> >Then RecordsAffected should be available before .. you can actually >>>simply >>>> >copy paste my example and run it and find out for yourself. >>>> > >>>> >- Sahil Malik >>>> >http://codebetter.com/blogs/sahil.malik/ >>>> > >>>> > >>>> > >>>> >"J L" <j***@marymonte.com> wrote in message >>>> >news:sa6g41lcqiq48pkivo9n24pm9podo336n0@4ax.com... >>>> >> I see your point. Good example. >>>> >> >>>> >> One minor question...the doc says the RowsAffected is not available >>>> >> until the reader is closed. So in your example, would you move the >>>> >> writeline reference outside the loop and close the reader first? >>>> >> >>>> >> John >>>> >> >>>> >> >>>> >> On Mon, 28 Mar 2005 02:20:44 -0500, "Sahil Malik" >>>> >> <contactmethrumyblog@nospam.com> wrote: >>>> >> >>>> >> >JL, >>>> >> > >>>> >> >A DataReader is the result of a DbCommand.ExecuteReader. >>>> >> >Now the DbCommand might have any command text - say a batched SQL >>>command >>>> >> >that might contain both inserts and updates. RecordsAffected will >>>> >> >help >>>> >you >>>> >> >get information out of those. >>>> >> > >>>> >> >You might ask "Why in the world would I want to batch my select >>>statement >>>> >> >with an insert statement" >>>> >> >Well say if you inserted a row, and now you wish to retreive the >>>latest >>>> >> >generated identity value, you could have code that looks somewhat >>>> >> >like >>>> >this. >>>> >> > >>>> >> >private const string CONN_STR = >>>"Server=(local);Database=Test;Integrated >>>> >> >Security=SSPI"; >>>> >> >static void Main(string[] args) >>>> >> >{ >>>> >> >using (SqlConnection conn = new SqlConnection(CONN_STR)) >>>> >> >{ >>>> >> >SqlCommand cmd = conn.CreateCommand(); >>>> >> >cmd.CommandText = "Insert into Animals (AnimalType) values >>>> >> >('Parrot'); >>>> >> >Select * from Animals"; >>>> >> >conn.Open(); >>>> >> >SqlDataReader rdr = cmd.ExecuteReader(); >>>> >> >while (rdr.Read()) >>>> >> >{ >>>> >> >Console.WriteLine(rdr.RecordsAffected); >>>> >> >System.Diagnostics.Debugger.Break(); >>>> >> >} >>>> >> >} >>>> >> >} >>>> >> >.. Obviously (before anyone corrects me), the better way to retreive >>>> >> >identites would be SCOPE_IDENTITY(). But hey .. I'm just tryin' to >>>make a >>>> >> >point here :-) >>>> >> >All this is explained in my upcoming book on ADO.NET 2.0 and more !! >>>> >> > >>>> >> >- Sahil Malik >>>> >> >http://codebetter.com/blogs/sahil.malik/ >>>> >> > >>>> >> > >>>> >> > >>>> >> > >>>> >> > >>>> >> >"J L" <j***@marymonte.com> wrote in message >>>> >> >news:vihc41pac4qo12ccgldu000c16et3sbi0e@4ax.com... >>>> >> >> Why and how is this property used? >>>> >> >> >>>> >> >> Documentation says it is number of rows changed, inserted, deleted >>>and >>>> >> >> can only be used after the DataReader is closed. I thought the >>>> >> >> DataReader was for forward read only access...so how can there be >>>rows >>>> >> >> changed/inserted/deleted? >>>> >> >> >>>> >> >> TIA >>>> >> >> John >>>> >> >> >>>> >> > >>>> >> >>>> > >>>> >>> >> >  |
|||||||||||||||||||||||
Other interesting topics