ASP.NET

Re: Data Reader [modified]

31-Jul-07 12:20

Have a look at this link[^], if you look at one of his replies (almost towards the end), he shows how to use DAAB with transactions.

Tarakeshwar Reddy
MCP, CCIE Q(R&S)

There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there. - Indira Gandhi

Data Reader [modified]

ASPnoob31-Jul-07 11:04

ASPnoob

31-Jul-07 11:04

Hi, suppose I connect to a database to retrieve binary data from a field called Resume and retrieve the mime type from the DocTypes field (DocTypes field stores "application/doc, image/img, etc.). I then use a data reader to read the data and then use the Response.ContentType=DirectCast(Read"DocType",String) to set its mime type. WhatI would like to know is, if the select statement used to retrieve the data retrieves more than one file, which DocType will be used in Response.ContentType=DirectCast(Read"DocType",String). Also if I decide to display the data using Response.Write(), whic file will be diplayed? I hope I'm making sense, thank you in advance for your help.

-- modified at 17:55 Tuesday 31st July, 2007

Re: Data Reader

Fred_Smith31-Jul-07 12:09

Fred_Smith

31-Jul-07 12:09

A datareader will return a set of rows, the order of which is determined by your sql query. If you are simply reading the first one then that is what will be displayed; otherwise you could loop through them and pick out whichever one you wanted (perhaps determined by an id passed in the querystring, though in that case you'd just return the one row to begin with. Really, for your scenario, you do only want to return the one row you want to display, and ought to try and make sure your datareader does only fetch that one row.)

ASPnoob31-Jul-07 12:21

ASPnoob

31-Jul-07 12:21

Hi, thanks for your response. Up 'til now I've been using a dataset and filling it using the data adapter Fill() method, but haven't used data reads that much. You said the order in which the rows are returned is determined by my SQL query, do you mean using the key word DESC or ASC? Also how do I loop through and pick what I want? Do I first put the retrieved data somewhere like a dataset then loop throught it? Please explain, thanks again for your help.

-- modified at 18:40 Tuesday 31st July, 2007

Re: Data Reader

Fred_Smith31-Jul-07 13:25

Fred_Smith

31-Jul-07 13:25

ASPnoob wrote:
do you mean using the key word DESC or ASC?

well, yes, amongst other things - basically the ORDER BY clause of your query

Dim objReader as SqlDataReader
Dim objCmd as New SqlCommand
...
objCmd.CommandText = "SELECT ... FROM ... WHERE ... ORDER BY..."
objReader = objCmd.ExecuteReader
If objReader.HasRows Then
Do While objReader.Read
' do stuff / test for condition
Loop
End If
objReader.Close

But really, I would have thought you would have determined the record you want to display already, probably on a previous page, and are calling this page with the ID (perhaps) of that one record, so you can retrieve it and set the page Response.ContentType accordingly - in which case you don't need to Do...Loop at all - just SELECT that one record in your SQL query

objCmd.CommandText = "SELECT ... WHERE ID = " & request("id")
objReader = objCmd.ExecuteReader
objReader.Read
...

Good luck - if you need more try looking up the 4guysfromrolla site - loads of examples - - I'mm off to bed!

Fred

How to remove a domain cookie ?

Ridge Howison31-Jul-07 10:46

Ridge Howison

31-Jul-07 10:46

Hi !

Thank you for reading this. Here is my problem. Iam creating a domain cookie so, other sites in my app can read values. How can i delete the cookie from the other site??? For example.. lets say my main site is www.abc.com, when user logs in, i create a domain level cookie like this

Dim cookie1 As HttpCookie = New HttpCookie("Cookie",1234567)
cookie1.Domain = ".abc.com"
cookie1.expires=datetime.now.addminutes(30d)
Response.Cookies.Add(cookie1)

this creates my domain cookie. my other site(lets say test.abc.com) reads this cookie...now i want to delete the domain cookie from test.abc.com. How do i do it? All help and code example are much appreciated.

Thanks
RH

Re: How to remove a domain cookie ?

Fred_Smith31-Jul-07 12:02

Fred_Smith

31-Jul-07 12:02

set its "expires" property to a date in the past.

If you want to do this across domains though, you may find that the user has set their browser security settings to prohibit you from doing this. Nothing you can do about that.

Re: How to remove a domain cookie ?

chand1031-Jul-07 19:58

chand10

31-Jul-07 19:58

Hi
When u r entering to other site, u first check for that cookie and remove it.

I have not failed. I've just found 10,000 ways that won't work. -Thomas A. Edison

Thank u
Chandu

Managing Frequently changing content

mrchief_200031-Jul-07 10:21

mrchief_2000

31-Jul-07 10:21

I have the following requirement:

E.g., on the UI, I have a grid with a list of items (having an unique id) and next to those items, I have a info icon which has a brief description about the item. The "text" that goes in the description is supplied to me by business and they want to have an ability to change it without code changes.

One way would be having an XML file like:

<infotips>
  <infotip>
    <id>101</id>
    <name>Information 1</name>
    <infotext>This is a description of Information 1</infotext>
  </infotips>
  <infotip>
    <id>102</id>
    <name>Information 2</name>
    <infotext>This is a description of Information 2</infotext>
  </infotips>
</infotips>

The problem is that XML file can easily be messed up by a simple typo or a special character. Enclosing in CDATA would still have the vulnerability of inputting improper XML structure.

So the question is, what is a good way to handle this type of scenario?

Thx in advance.

plsql decode

Hasan Ali31-Jul-07 9:49

Hasan Ali

31-Jul-07 9:49

Could I use plsql decode to change value of a column in same record after checking for a condition in another column...

SELECT supplier_name,
decode(supplier_id, 10000, 'IBM',
10001, 'Microsoft',
10002, 'Hewlett Packard',
'Gateway') result
FROM suppliers;

Re: plsql decode

Hasan Ali31-Jul-07 10:23

Hasan Ali

31-Jul-07 10:23

I found 2 solutions :
Objective:
A table having 2 columns flag and amt. If the flag = Y then the amount should be XXX
else the original amount should be printed.

Solution:

#1
select
decode( nvl(flag,'N'), 'Y', 'XXX', to_char(amt,'999.99') ) amt
from Arif_table
/

#2
select
(
CASE when nvl(flag,'N') = 'Y' then
'XXX'
ELSE
to_char(amt,'999.99')
END CASE
) amt
from Arif_table
/

Availability Calendar

munklefish31-Jul-07 8:09

31-Jul-07 8:09

Hi,

Im developing a property rentals website (.Net 2.0 c#) and need to produce a calendar on which property owners can indicate the availability of their property. Then in turn visitors to the site can view the calendar to see when its book or available.

Can anyone give me some ideas on how to do this, short of adding 365 fields in a database to account for each day of the year??? Any help or even links would be greatly appreciated as ive done some serious searches and cant find anything suitable.

Thanks in advance for your time!
Phil

Tarakeshwar Reddy31-Jul-07 8:26

31-Jul-07 8:26

It depends on how you want the screen to look like. I would store the date ranges for a particular property in a separate table and use a primary-foreign key to pull the data. If the calendar needs to show availability for a particular property, then you could get the date ranges from the database and set the dates in the calendar with a color or a style you want.

The default calendar in .net would not allow you to select multiple dates, you will have to create a custom control extending the calendar class. Override the OnDayRender property of the calendar and based on the data from database do a tablecell.ApplyStyle(tableitemstyle) for each of the dates.

Tarakeshwar Reddy
MCP, CCIE Q(R&S)

There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there. - Indira Gandhi

munklefish31-Jul-07 8:34

31-Jul-07 8:34

Hi,

Thanks for the reply but its not quite what i was looking for (i dont think).

1) How do i go about recording availability without the user manually selecting every single date on which the property is available.

2) How do i store this data without having 365 data fields per year in which to store the availability of each individual date?

3) I dont quite follow what you mean by 'primary-foreign key'. Excuse my ignorance.

4) PLEASE PLEASE HELP. Wink | ;-)

Thanks!!!
Phil

Tarakeshwar Reddy31-Jul-07 8:51

31-Jul-07 8:51

For one of my project, I had to create a yearly calendar to select a list of dates. I created a custom control extending the calendar control, the user could click on any date on the calendar and that would get added into the database. I had added the DataSourceID property to the calendar control and based on the select statement picked the required dates from the database and applied a color to the dates to show it as selected. Clicking on an existing date would remove that particular date from the database and remove the style applied to it.

Lets say for example that your table structure is something like below (I have put tbl in front of table just to indicate its a table name)

tblProperty                             tblAvailDates
(                                       (
   PropertyID,  <pk> <-----------> <fk>   PropertyID
   Description,                           DateStart,   
   ContactName,                           DateEnd
   PhoneNo                               )
)

Use an Inner Join on tblProperty and tblAvailDates to pick the date ranges(which is DateStart to DateEnd) using the relation PropertyID. This way you do not store 365 days in a table but store the date ranges of availability(ex: PropertyID: 1010, DateStart: July, 30th 2007, DateEnd: Nov, 30th 2007).

munklefish wrote:
1) How do i go about recording availability without the user manually selecting every single date on which the property is available.

You can use a date picker to pick start and end dates and store it in a listbox or any kind of control you want, and give the user option edit/delete them.

Tarakeshwar Reddy
MCP, CCIE Q(R&S)

There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there. - Indira Gandhi

munklefish31-Jul-07 11:20

31-Jul-07 11:20

Thanks for the excellent and detailed response!!!

This is really helpful and would certainly go along way towards what my clients need. However at rpresent they are being quite demanding in that they are very keen to be able to select individual dates rather than blocks of days.

Do you have any further suggestions by any chance???

Thanks again for your help so far.
Phil

Tarakeshwar Reddy31-Jul-07 12:15

31-Jul-07 12:15

In that case convert the table to have just one field DateSelected instead of DateStart and DateEnd. Looks like you will end up with a lot of rows.

The custom control I was talking about, had the same requirement as yours, I needed to have the user select individual dates, since the no of rows I had to deal with was less than 50, I had put each row in the database.

The other alternative you may want to do is to put all the dates into an XML string and store that in the database. The XML string can be read into a dataset and you could iterate through each row of the dataset and apply the style.

tblProperty
(
   PropertyID,
   Description,
   ContactName,
   PhoneNo,
   PropertyDatesXML
)

For loading the dates, you can do something like this in the custom control

foreach(DataRow dr in dsPropertyDatesXML.Tables[0].Rows)
{
      //apply the style to the date
}

To add individual dates into the database, overide the OnSelectionChanged() of the control and store them in an arraylist/list and when your storing it into the database, create the XML string from the list and store it into the database..

I am not sure about the performance. I guess you will get some more ideas from rest of the people and you could combine the ideas to accomplish what your looking for.

Tarakeshwar Reddy
MCP, CCIE Q(R&S)

There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there. - Indira Gandhi

munklefish1-Aug-07 0:04