C# Discussion Boards - CodeProject

Re: Clear a tab contents when i switch tabs

Jay Nardev13-Apr-14 7:19

Jay Nardev

13-Apr-14 7:19

Check the active index of tab on tab click and set the text box blank.

Re: Clear a tab contents when i switch tabs

alfie.max1513-Apr-14 9:30

alfie.max15

13-Apr-14 9:30

Thnx... I did consider your suggestion and used tab Deselecting event....

Thnx again...

Large Numer Calculation

Meysam Toluie12-Apr-14 23:40

Meysam Toluie

12-Apr-14 23:40

Why the following code gives me this:
1000000000000000019884624838656
instead of
1000000000000000000000000000000

BigInteger result = new BigInteger(Math.Pow(1000, 10));

Re: Large Numer Calculation

Richard MacCutchan13-Apr-14 0:23

Richard MacCutchan

13-Apr-14 0:23

The Math.Pow method[^] returns a Double. Such values lose precision when very small or very large, hence the result you see. Why not use http://msdn.microsoft.com/en-us/library/system.numerics.biginteger.pow(v=vs.110).aspx[^].

Re: Large Numer Calculation

Meysam Toluie13-Apr-14 4:02

Meysam Toluie

13-Apr-14 4:02

Thanks a lot.

Re: Large Numer Calculation

kamran2313-Apr-14 10:54

kamran23

13-Apr-14 10:54

excuse me are you from iran

Re: Large Numer Calculation

Meysam Toluie13-Apr-14 18:02

Meysam Toluie

13-Apr-14 18:02

Yes, I am.

Lognormal distribution

Member 1074517412-Apr-14 23:16

Member 10745174

12-Apr-14 23:16

I am trying to use Lognormal distribution in one of my projects and require the inverse Cumulative distribution function.

Any help would really be appreciated

Re: Lognormal distribution

Richard MacCutchan13-Apr-14 0:21

Richard MacCutchan

13-Apr-14 0:21

Help with what? If you expect sdomeone to write the code for you then you are going to be disappointed. Please read http://www.codeproject.com/Messages/1278604/How-to-get-an-answer-to-your-question.aspx[^], and provide proper details of your problem.

Re: Lognormal distribution

Member 1074517413-Apr-14 0:39

Member 10745174

13-Apr-14 0:39

Thank you Richard, I was not looking for a code. using lognormal means that I need to use the inverse of an ERF or ERFC. I know that both are implemented in c#, and was merely looking for some help in directing my search.

Re: Lognormal distribution

Richard MacCutchan13-Apr-14 0:47

Richard MacCutchan

13-Apr-14 0:47

Member 10745174 wrote:
help in directing my search

Did you try https://www.google.com/search?q=lognormal+c%23[^]?

How to create form search (c#-winform-sql server) with multi-field

joga778512-Apr-14 0:06

joga7785

12-Apr-14 0:06

Re: How to create form search (c#-winform-sql server) with multi-field

Peter Leow12-Apr-14 0:34

Peter Leow

12-Apr-14 0:34

SQL

select * from tablename where
name = 'JON' and
address like '%New%' and
age between 18 and 50

Re: How to create form search (c#-winform-sql server) with multi-field

joga778513-Apr-14 16:39

joga7785

13-Apr-14 16:39

Thanks Guy,

This problem is difficult. User can select the operator ">" or "<" or "between" ,...- not fix.
After user select some operator and input some values, we will create sql query

Re: How to create form search (c#-winform-sql server) with multi-field

Mycroft Holmes12-Apr-14 14:50

Mycroft Holmes

12-Apr-14 14:50

Peter Leow supplied the script here is some more

Create a form with 3 text boxes a button (Search) and a grid.
when the user clicks the search button trap the event and
make a connection to the database
pass in the query based on the data entered into the textboxes (using PLs query example)
get the dataset from the sql command object
bind the datatable to your datagridview

Improve the query by using parameters - see "Little Bobby Tables"

Never underestimate the power of human stupidity
RAH

Re: How to create form search (c#-winform-sql server) with multi-field

joga778513-Apr-14 16:40

joga7785

13-Apr-14 16:40

Thanks Guy,

This problem is difficult. User can select the operator ">" or "<" or "between" ,...- not fix.
After user select some operator and input some value, we will create sql query

Re: How to create form search (c#-winform-sql server) with multi-field

Bernhard Hiller13-Apr-14 23:01

Bernhard Hiller

13-Apr-14 23:01

Create a class Criterion with 4 string properties: Name, Operation, Value, SecondValue - yes, the SecondValue is required in such rare case like that "between". Also create a collection class for it, e.g. Criteria:List<Criterion>.
The most complicated part is the ToSQL() of Criterion. In many cases, simple concatenation will suffice.
Then start your query with
string query = "SELECT * FROM MYTABLE WHERE 1=1 "
then simply iterate thru the collection and add
query += " AND " criterion.ToSQL();
Well, that is still open to SQL Injection. Update the ToSQL function and do another loop to add the parameters then (next step - doing it in one step is surely still beyond your level, but with two steps, you could do it).

Re: How to create form search (c#-winform-sql server) with multi-field

joga778520-Apr-14 16:47

joga7785

20-Apr-14 16:47

thank your comment. i will try with this solution

Re: How to create form search (c#-winform-sql server) with multi-field

joga778520-Apr-14 18:44

joga7785

20-Apr-14 18:44

My funtion done:

private void radButton1_Click(object sender, EventArgs e)
        {
            string query = "SELECT * FROM Mytable WHERE 1=1 ";
            if (txtValue1.Text.ToString()!= "")
            {
                query += " AND " + OpeReturn(FullName.Name.ToString(), cboOpe1.SelectedIndex.ToString(), txtValue1.Text.ToString());
            }
            if (value2.Text.ToString() != "")
            {
                query += " AND " + OpeReturn(TotalAmount.Name.ToString(), cboOpe2.SelectedIndex.ToString(), value2.Text.ToString());
            }
            query.ToString();
            SearchContractBindingSource.DataSource = RemoteClient.remoteData.QueryHopDongBan(query);
        }

private string OpeReturn(string field, string ope, string value)
        {
            switch (ope)
            {
                case "0":
                    return field + " like " + "'%" + value + "%'";
                case "1":
                    return field + " not like " + "%" + value + "%";
                case "2":
                    return field + " like " + value + "%";
                case "3":
                    return field + " like " + "%" + value;
                case "4":
                    return field + " = " + value;
                case "5":
                    return field + " != " + value;
                case "6":
                    int index = value.IndexOf(" ");
                    string value1 = (index > 0 ? value.Substring(0, index) : "");
                    string value2 = (index > 0 ? value.Substring(index + 1) : "");
                    return field + " > '" + value1 + "' AND " + field + " < '" + value2 + "'";
                case "7":
                    return field + " > " + value;
                case "8":
                    return field + " >= " + value;
                case "9":
                    return field + " < " + value;
                case "10":
                    return field + " <= " + value;
                default:
                    return " 1 = 1 ";
            }
        }