update the database using dataadpater in asp.net

[muskan]

hello,

I have written this code on button_click event.
but it shows "Object reference not set to an instance of an object" error.
can u help to solve this error.

String conn= "data source= VTECHS; database= bc;uid=greymount;password= manish2809";
String str= "select * from details";
SqlDataAdapter da= new SqlDataAdapter(str,conn);
SqlCommandBuilder commb=new SqlCommandBuilder(da);
DataSet ds =new DataSet();
da.Fill(ds);
DataTable dt=new DataTable();
dt=ds.Tables["details"];
dataRow rownew= ds.Tables["details"].NewRow();
rownew["name"]=txtLcode.Text ;
ds.Tables["details"].Rows.Add(rownew);
da.Update(ds);

[shweta123]

Have u opened the connection?
because SqlDataAdapter da= new SqlDataAdapter(str,conn);
Here con is your connectionstring .So yuo might be getting error there

Shweta

[muskan]

Thanks for reply........
but i have opened the connection in the code.

I have written like tht but it is still not working.


SqlConnection conn= new SqlConnection ("data source= VTECHS; database= abc;uid=greymount;password= manish2809");
conn.Open();

SqlDataAdapter da= new SqlDataAdapter(new SqlCommand("select * from details",conn));

Please help me to solve this query.

[radcaesar]

Why did u use the command builder there ?

Remove the command builder.

Also, when u create a Datase, it has a Data Table.

U can access it directly by ds.Tables[0]

Try to reduce the code and finish it.

:)

[vinaykeshav]

check if the database already exists for which your trying to access from code.
also debug and find out where exactly its breaking...

[muskan]

thanks for reply.

actually I want to insert the new record into the table.

[muskan]

when I debug, error is showing in this line

dataRow rownew= ds.Tables["details"].NewRow();

[vinaykeshav]

dataRow rownew= ds.Tables["details"].NewRow();[/quote]

make the above line

DataRow rownew= ds.Tables["details"].NewRow();[/quote]
the datarow should b in caps..
and plz check u have this at the top
using System.Data;
using System.Data.SqlClient;

[muskan]

thanks......

my problem is solved.

now I have used ds.Tables[0].
but command builder is necessary becoz I want to insert new record into table
& it provides many other useful commands to dataadapter such as insert command which is useful for adding the new record into database.

Why did u use the command builder there ?

Remove the command builder.

Also, when u create a Datase, it has a Data Table.

U can access it directly by ds.Tables[0]

Try to reduce the code and finish it.

:)

[vinaykeshav]

DataTable dt =new DataTable();
dt=ds.Tables["details"];

//ds.Tables["details"].NewRow();
dt.NewRow();

that was the gud soln to the probs i thought u could have done this..
thats taking new row from the datatable instead of ds..

[chauhanavneesh]

hello,

I have written this code on button_click event.
but it shows "Object reference not set to an instance of an object" error.
can u help to solve this error.

String conn= "data source= VTECHS; database= bc;uid=greymount;password= manish2809";
String str= "select * from details";
SqlDataAdapter da= new SqlDataAdapter(str,conn);
SqlCommandBuilder commb=new SqlCommandBuilder(da);
DataSet ds =new DataSet();
da.Fill(ds);
DataTable dt=new DataTable();
dt=ds.Tables["details"];
dataRow rownew= ds.Tables["details"].NewRow();
rownew["name"]=txtLcode.Text ;
ds.Tables["details"].Rows.Add(rownew);
da.Update(ds);

Its give me ==>a syntax error in insert into statement.
please solve my problem