Write data to textbox with datareader

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Hi,

I am creating a website project and I need to write data to textbox from database.
I used datareader. I am sure that it is connected to database, but it can not penetrate into while loop.
Could anyone help me?

Here is my code;

C#

SqlConnection conn = new SqlConnection();
SqlDataReader dr;

string TCNumber = Request.QueryString["TC"].ToString();
                    

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC='"+TCNumber+"'");

comm2.Connection = conn;

dr = comm2.ExecuteReader();

while (dr.Read())
{
       TCNo.Text = dr["TC"].ToString();
       Name.Text = dr["Name"].ToString();
       Surname.Text = dr["Surname"].ToString();
       BirthDate.Text = dr[3].ToString();
       Phone_Number.Text = dr[4].ToString();
}
dr.Close();
dr.Dispose();
conn.Close();

Posted 31-Jul-12 21:48pm

sesenyg

Updated 31-Jul-12 21:54pm

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

v2

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Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) · Answer 1 · 2012-07-31T21:59:00

Solution 1

You have not opened your connection.
so write

C#

comm2.Connection.Open();

after the line

C#

comm2.Connection = conn;

and before the line

C#

dr = comm2.ExecuteReader();

Hope it solves your problem.
Please let me know...

Posted 31-Jul-12 21:59pm

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

Updated 31-Jul-12 22:00pm

v2

Comments

sesenyg 1-Aug-12 4:02am

No, unfortunatelly it is not, i did not add my connection lines there. The problem is not connection problem:(

OriginalGriff · Answer 2 · 2012-07-31T22:02:00

Every time you go round your loop, you set the new value of each textbox, and discard any previous value. So if you have more than one row where TC is equal to TCNumber then only the last will be displayed - this is probably not what you want. I don't know exactly what you are trying to achieve, so I can't suggest a solution, other than "Try using += instead of ="

If you don't have any that match, nothing will be displayed at all. If not of your records are displaying, then either you have not records that match, or your querystring does not contain what you think it does.

And BTW: Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.

Himanshu Yadav · Answer 3 · 2012-07-31T22:07:00

Solution 4

Hi Every thing is fine just open the connection as follows....

SqlConnection conn = new SqlConnection();
SqlDataReader dr;
 
string TCNumber = Request.QueryString["TC"].ToString();
                    
 
SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC='"+TCNumber+"'");
 
comm2.Connection = conn;
  conn.Open();
dr = comm2.ExecuteReader();
 
while (dr.Read())
{
       TCNo.Text = dr["TC"].ToString();
       Name.Text = dr["Name"].ToString();
       Surname.Text = dr["Surname"].ToString();
       BirthDate.Text = dr[3].ToString();
       Phone_Number.Text = dr[4].ToString();
}
dr.Close();
dr.Dispose();
conn.Close();

Posted 31-Jul-12 22:07pm

Himanshu Yadav

Updated 31-Jul-12 22:09pm

v2

Comments

Himanshu Yadav 1-Aug-12 4:10am

Hi Please pass connection string As per your data base.
SqlConnection conn = new SqlConnection("server=sam-pc;database=wipro;user id=sa;pwd=godfather")

Himanshu Yadav 1-Aug-12 4:13am

is it working now?

Himanshu Yadav 1-Aug-12 4:26am

For me it is working fine are sure there is data against that query

sesenyg 1-Aug-12 4:14am

This is my whole code, i said the problem is not connection problem:(

SqlConnection conn = new SqlConnection();
SqlDataReader dr;
conn.ConnectionString = "server= ***; user = ***; pwd= ***; database = ***";
conn.Open();
string TCNumber = Request.QueryString["TC"].ToString();
SqlCommand comm = new SqlCommand("SELECT Sistolic,Diastolic,Pulse,Date from

MeasureRecords WHERE TC='"+TCNumber+"'");
SqlDataAdapter adap = new SqlDataAdapter(comm);

comm.Connection=conn;
DataSet ds = new DataSet();
adap.Fill(ds);

MeasureRecord.DataSource = ds;
MeasureRecord.DataBind();

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC='"+TCNumber+"'");
comm2.Connection = conn;
dr = comm2.ExecuteReader();

while (dr.Read())
{
TCNo.Text = dr["TC"].ToString();
Name.Text = dr["Name"].ToString();
Surname.Text = dr["Surname"].ToString();
BirthDate.Text = dr[3].ToString();
Phone_Number.Text = dr[4].ToString();
}
dr.Close();
dr.Dispose();
conn.Close();

sesenyg 1-Aug-12 4:18am

And i can get data to my gridview 'MeasureRecord' so the problem is really not connection problem..

pradiprenushe 1-Aug-12 4:20am

Is your execution going in while loop? What actually you trying to get & what is happening?

sesenyg 1-Aug-12 4:25am

I try to get data from database to write textboxes on website. TC is primary key, so it can not leave null. The code can not enter while loop , because i put a breakpoint in while loop but it did not stop anywhere.

Himanshu Yadav 1-Aug-12 4:27am

Check yr query is data is comming
run that query in sql and check data is coming or not

Himanshu Yadav 1-Aug-12 4:31am

what happen data is coming?

pradiprenushe 1-Aug-12 4:33am

Copy your query in sql query editor take querystring value for which you are testing. And check for output. As I said in my solution your query is not returning data. So dr.Read() is false. That why execution not going in while loop.

sesenyg 1-Aug-12 4:33am

Data is coming but i think the problem is datareader. It realize that it is empty.

Himanshu Yadav 1-Aug-12 4:39am

try this code.....
SqlDataAdapter adap = new SqlDataAdapter(comm);

comm.Connection = conn;
DataTable dt = new DataTable();
adap.Fill(dt);
foreach (DataRow datarw in dt.Rows)
{
TCNo.Text= datarw["TC"].ToString();
....
.......
}

Himanshu Yadav 1-Aug-12 4:41am

Hope this will work.

Himanshu Yadav 1-Aug-12 4:47am

Check by puting this either dr has rows.

bool chk= dr.HasRows;

pradiprenushe 1-Aug-12 4:45am

Try dr.HasRows() instead of dr.Read() & check result.

sesenyg 1-Aug-12 4:48am

No, it did not:'(

sesenyg 1-Aug-12 4:49am

I already try this. No rows returns. dr is empty

pradiprenushe 1-Aug-12 4:53am

Try my updated answer. Tell me if it works i will provide you reason.

sesenyg 1-Aug-12 4:58am

i tried your datatable, dataadapter method. I realize dt is empty this time. I really don't understand, how my first sql command works fine but second returns null value??

And when i tried to dr.HasRows() method. It did not work again:(

Himanshu Yadav 1-Aug-12 5:16am

I tried yr code like this is is working

SqlConnection conn = new SqlConnection("server=sam-pc;database=wipro;user id=sa;pwd=godfather");
SqlDataReader dr;
conn.Open();
//string TCNumber = Request.QueryString["TC"].ToString();
SqlCommand comm = new SqlCommand("select * from EmpDetail");
SqlDataAdapter adap = new SqlDataAdapter(comm);
comm.Connection = conn;
DataSet ds = new DataSet();
adap.Fill(ds);
MeasureRecord.DataSource = ds;
MeasureRecord.DataBind();

SqlCommand comm2 = new SqlCommand("select * from EmpDetail");
comm2.Connection = conn;
SqlDataAdapter adap1 = new SqlDataAdapter(comm2);
comm2.Connection = conn;
DataTable dt = new DataTable();
adap1.Fill(dt);
foreach (DataRow Datadr in dt.Rows)
{
string s = string.Empty;
}

//dr.Dispose();
conn.Close();

Himanshu Yadav 1-Aug-12 5:19am

Hi in this query remove where condition and check data is coming or not.

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC='" + TCNumber + "'");

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info");

pradiprenushe 1-Aug-12 5:32am

I think your TC is int filed in database. In query you are passing it with single quote. I think you should try without single quote & convert value to integer as per my updated solution.

sesenyg 1-Aug-12 6:17am

Thanks for your helps:)

graciax8 · Answer 4 · 2012-07-31T22:16:00

Solution 5

try this one.

C#

while (dr.Read())
{
       TCNo.Text = dr.GetString("TC");
       Name.Text = dr.GetString("Name");
       Surname.Text = dr.GetString("Surname");
       BirthDate.Text = dr.GetString(3];
       Phone_Number.Text = dr.GetString(4);
}

Posted 31-Jul-12 22:16pm

graciax8

Comments

sesenyg 1-Aug-12 4:26am

No, it did not work again:(

graciax8 1-Aug-12 4:40am

are you sure your query string is getting a value. can you check the output of Request.QueryString["TC"].ToString(); first? thanks.

sesenyg 1-Aug-12 4:53am

I have two sql command one of them work fine and i used my request.querystring value on my first sqlcommand. It returns the true value.

graciax8 1-Aug-12 5:10am

declare a new connectionstring for your second query.
SqlConnection conn2 = new SqlConnection();

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC='"+TCNumber+"'");
comm2.Connection = conn2;

your code is kinda messy i suggest you clean it. hope this finally solves your problem. Goodluck!

sesenyg 1-Aug-12 6:17am

thanks for your attention.

graciax8 2-Aug-12 1:38am

have you solved it?

sesenyg 2-Aug-12 2:53am

yeap i did:)

graciax8 2-Aug-12 4:38am

if our solutions helped kindly marked it as answered so others will konw. thanks! :)

pradiprenushe · Answer 5 · 2012-07-31T22:01:00

Change this line

SQL

SqlCommand comm2 = new SqlCommand("SELECT TC, Name, Surname, BirthDate, Phone from Pers_Info WHERE TC="+Convert.ToInt32(TCNumber)+"");

Your query is returning 0 row. So this is correct behavior.
Add breakpoint at while loop & check flow of execution .
When execution cone to breakpoint right click on dr -> quick watch and paste dr["TC"].ToString().
See the output you will get idea.

Write data to textbox with datareader

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