Re: c# and query result - C# Discussion Boards

User34903-Jul-13 10:15

3-Jul-13 10:15

when the query is false how can i take the result so i can use it for doing something else with this

Pete O'Hanlon3-Jul-13 10:20

Pete O'Hanlon

3-Jul-13 10:20

What query? How is it returning false? You haven't shown a query.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

User34903-Jul-13 10:23

3-Jul-13 10:23

OleDbConnection dbConnDest;
dbConnDest = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source= SystemA.accdb");

string query_select = "SELECT ReferenceYear FROM [MS Access;DATABASE=" + dialog.FileName +"].Questionnaires_Table1 Where ReferenceYear = '" + dateref.Text + "';";

OleDbCommand cmd_year = new OleDbCommand(query_select, dbConnDest);
dbConnDest.Open();
string rfyear = cmd_year.ExecuteScalar().ToString();

Pete O'Hanlon3-Jul-13 10:29

Pete O'Hanlon

3-Jul-13 10:29

So all you're doing is testing to see if ReferenceYear exists? Why not just do SELECT Count(1)... instead, and then just evaluate the count? If it's zero, the record doesn't exist? Also, you may want to pay attention to the fact your select statement is vulnerable to a SQL Injection attack.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

KiranKumar Roy3-Jul-13 20:10

KiranKumar Roy

3-Jul-13 20:10

Exactly true.. Smile | :)

KiranKumar Roy

User34904-Jul-13 11:11

4-Jul-13 11:11

ok i make a class and i have there the following code:

public DataTable findrefyear(string dateref)
{

try
{
//Set the access command string
string query_insert = "INSERT INTO Questionnaires_Table (BranchName,Factor,Region,Branch_ID,[Current_Date],No_Employees,"
+ "No_Cashdesk,UrbanArea,TouristArea,RuralArea,GreenLinearArea,CentralStreets,EscapeBack,Collonization,"
+ "TimeDelay,PatrolPolice,Visibility,SafeBoxRisk,StaffAccess,KeyboardActiviation,ConnectionKSC,GSMCommunicator,SystemAlarmRisk,"
+ "InstalledSKKT,CheckSKKT,CheckDesk,CheckEntrance,SKKTRisk,RenovatedStore,MetalCashDrawers,ExtensionCash,Limits,"
+ "CashDrawers,CasherRisk,WarningAlert,SecurityWarningDelay,WarningRisk,BothSideDoors,"
+ "DoorsSound,ExitRisk,EmergencyCase,RobberyCase,DescriptionForm,SeminarRobbery,EducationRisk,ReferenceYear) "
+ "SELECT BranchName,Factor,Region,Branch_ID,Current_Date,No_Employees,"
+ "No_Cashdesk,UrbanArea,TouristArea,RuralArea,GreenLinearArea,CentralStreets,EscapeBack,Collonization,"
+ "TimeDelay,PatrolPolice,Visibility,(TimeDelay+PatrolPolice+Visibility)/3,StaffAccess,KeyboardActiviation,ConnectionKSC,GSMCommunicator,(StaffAccess+KeyboardActiviation+ConnectionKSC+GSMCommunicator)/4,"
+ "InstalledSKKT,CheckSKKT,CheckDesk,CheckEntrance,(InstalledSKKT+CheckSKKT)/2,RenovatedStore,MetalCashDrawers,ExtensionCash,Limits,"
+ "CashDrawers,(CheckDesk+CheckEntrance+RenovatedStore+MetalCashDrawers+ExtensionCash+Limits+CashDrawers)/7,"
+ "WarningAlert,SecurityWarningDelay,(WarningAlert+SecurityWarningDelay)/2,BothSideDoors,"
+ "DoorsSound,(BothSideDoors+DoorsSound)/2,"
+ "EmergencyCase,RobberyCase,DescriptionForm,SeminarRobbery,(EmergencyCase+RobberyCase+DescriptionForm+SeminarRobbery)/4,ReferenceYear "
+ "FROM [MS Access;DATABASE=" + dialog.FileName + "].Questionnaires_Table1 Where ReferenceYear = '" +dateref + "';";

//create new new access connection to the database
OleDbConnection conn = new OleDbConnection(ConnectionString);
//create new access data adapter
OleDbDataAdapter oleDBAdapter = new OleDbDataAdapter(query_insert, conn);
//create new access command builder
OleDbCommandBuilder oleDBBuilder = new OleDbCommandBuilder(oleDBAdapter);

dTable = new DataTable();
oleDBAdapter.Fill(dTable);
conn.Close();
}
catch (OleDbException e)
{
MessageBox.Show(e.ToString());
}
//return the search results on a datatable
return dTable;

}

Also i have in appropriate form the following code that call the query when it is work:

dbConnDest.Open();

DataTable find_data = importrefyear.findrefyear(dateref.Text);
if (find_data.Rows.Count >= 1)
{
"How i CAll the query from here???"

}

Also the SELECT Count(1)is the above method i use ??

c# and query result

User34903-Jul-13 7:21

3-Jul-13 7:21

What is the result of a query in c# when is false or is true
for example i have the following query and i want to do something when is false. How i manage this?

string rfyear = ((string)cmd_year.ExecuteScalar());

i want to manage with "if" if i can to do something like this...

if (rfyear.Length == 0) { MessageBox.Show("the query is false "); }
else{ MessageBox.Show("OK");
textBox1.Text = rfyear;

Common Trace Format in C#

OriginalGriff3-Jul-13 8:35

OriginalGriff

3-Jul-13 8:35

It all depends on what your query is actually returning: it is very possible that your line:

string rfyear = ((string)cmd_year.ExecuteScalar());

Will not work, but throw an InvalidCastException because the data coming back can't be cast to a string - it may work if you change it to:

string rfyear = cmd_year.ExecuteScalar().ToString();

But...I wouldn't recommend it as there is a very good chance that you will get a string containing the name of the type of the value returned.

What does your query return when it works and when it fails?

The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)

srikumarrampa3-Jul-13 4:08

srikumarrampa

3-Jul-13 4:08

I just came to know about the Linux tracing tool mechanism available in Java (LTTng - Linux Tracing Toolkit Next Generation).
It actually is a framework that provides analysis of traces and events on a linux machine.
I want to develop a windows application which will read linux traces(usually in CTF format - common Trace Format) from a file and decode the value and time of trace. This application runs on Windows PC.

Can any body suggest me the best possible approach for this?

Re: Common Trace Format in C#

Pete O'Hanlon3-Jul-13 4:51

Pete O'Hanlon

3-Jul-13 4:51

If I were looking to do this, I'd first of all look to see if anyone had already written code that did this; if they hadn't, I'd then look at the specifications[^].

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Install application without install SQLSERVER

dharmaa.m2-Jul-13 8:38

dharmaa.m

2-Jul-13 8:38

I've made an application that works with SQL database. Now want without install the software SQL on client computer ,an applicationto work.
what way do you suggest?

Ron Beyer2-Jul-13 9:18

Ron Beyer

2-Jul-13 9:18

Use a different database, like SQLite. SQL Server must be on the client computer, or the client computer must be able to connect to the SQL server remotely, it doesn't run without the back-end installed on something that it can talk to.

dharmaa.m2-Jul-13 9:44

dharmaa.m

2-Jul-13 9:44

Ron Beyer wrote:
or the client computer must be able to connect to the SQL server remotely, it doesn't run without the back-end installed on something that it can talk to.

Thanks for the Answer
Can you explain more about connecting remotely, step by step
Thanks...

Ron Beyer2-Jul-13 9:50

Ron Beyer

2-Jul-13 9:50

1. You host the SQL server on a computer somewhere that all the clients can see.
2. Your connection string contains information to address the server.
3. Use SQL commands as normal.

Its not difficult, the only thing you have to do is make sure that the host server is accessible from the clients and that you get the connection string right. See SQL Server 2012 Connection Strings[^] or SQL Server 2008 Connection Strings[^] or SQL Server 2005 Connection Strings[^].

Manu V Nath3-Jul-13 23:30

Manu V Nath

3-Jul-13 23:30

I think you are not talking about web application. In web application DB will setup in SQL server. For a desktop application sql server is not a recommended DB. You have setup SQL server in client machine also for desktop app