|
Hello,
I am building a Windows Forms .NET application entirely using typed DataSets. It is a straightforward administration application which does CRUD and some more for many tables in a database. The strategy we have followed on data access is to get all records to the client, then use them. So the Windows Forms application running on the client PC always has a complete set of records, reflecting the database. To save updates we use the GetChanges() method, so only updates are sent to the data layer. To keep the data current, the DataSets are regularly refreshed from the database.
Working entirely with typed DataSets in the presentation layer has many advantages. The basic functionality for scrolling through a table, editing records, filtering, selecting, is all there. DataSets have their peculiarities, but once you have learned to handle these, DataSets are just a pleasure to work with.
Now introducing my problem: performance with large numbers of records. All is well with tables of <10000 records. Data is loaded in couple of seconds and the performance on the client side is definitely sufficient. One part of the application however has a much larger number of records. One table has about 200000 records, and a related table has about 600000. Filling the typed DataSet with these tables works, but it takes over a minute to complete. Furthermore the performance of the application when working with this DataSet is far too low, even on modern hardware. E.g. finding a row takes seconds, not milliseconds.
I realize it's foolish to think that it is good practice to load such a large database entirely to the clients. However, I want to use the power of DataSets. How can I do this, without requiring enormous changes to the application? Any hints on and links to best practices to handle this situation would be greatly appreciated.
Regards,
Aron van Ammers
|
|
|
|
|
Hi there ,
i use c# to insert a money data type from a textbox but it give an exception :
i used SqlMoney.Parse(textbox.text.trim()) it dosnt work
the exception is :
Disallowed implicit conversion from data type varchar to data type money
thanks
Haytham
|
|
|
|
|
How is the number formatted in the textbox? I use this to convert the string "€ 1,90" to the decimal 1.9:
Decimal.Parse(cevent.Value.ToString(), NumberStyles.Currency, null);
cheers,
Aron
|
|
|
|
|
I am not getting any idea how to connect to the DB2 database. Can anyone give me ideas about it?
|
|
|
|
|
<%@ Page Language="c#" Debug="true" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.OleDb" %>
import these things
1.write your sql statement
2.open a connection like this: OleDbConnection myConn = new OleDbConnection ("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("db2.mdb"));
this will connect to DB2
(And if you want further assistance my suggestion is read a book )
leo
|
|
|
|
|
Hi,
I am getting some data from database to a dataset, binding it with a datagrid and everything works fine. Now the task ahead is like this :
The database may be changed by other user/server. Then I will get an alert. On reciving the alert I have to update the display in the datagrid. Since there are many rows in the datagrid, I cannot reload it again. So, I want read only the updated row from the database to dataset (I know which row is updated..like I know the primary key filed value)and update the data in the datagrid.
Any ideas? An example would be great!
Cheers
CNU
|
|
|
|
|
heres the statement
Private Sub CmdSQL_Click()<br />
Dim strSearchLName, strSearchFName As String<br />
strSearchLName = txtSearchLName.Text<br />
strSearchFName = txtSearchFName.Text<br />
adoRecords.RecordSource = "Select * FROM Users Where (Last_Name) = '" & strSearchLName & "' AND (FName) = '" & strSearchFName & "' "
the varibles are getting the correct information. if i search with 1 varible, there isn't a problem.
Any ideas???
here are the order of steps:
user enters their first name & Last Name into text boxes.
they click a button a screen pops up, showing their contact info. then the log in form shows and they need to click th log in button right now, all the contacts in the contacts table are showing but if i search with only the last name, it only shows the correct contact in the form.
|
|
|
|
|
If you only put last name, the SQL statement will be like
SELECT * FROM Users WHERE Last_Name = 'LName' AND FName = ''
Most likely it won't return you anything as there won't be a person with FName = ''
The easiest way is to use AND FName LIKE'" & strSearchFName & "%'"
The recommended way is to make sure your SQL is correct (build a dynamic SQL, e.g. remove FName from condition if FName is not supplied)
Hope it helps,
Edbert P.
Sydney, Australia.
|
|
|
|
|
i have another question that i need help in solving it or at least a hint
please......................
i hope you cn help me solve it...
Write down a single SQL statement that displays the following output by using tables EMP and DEPT.
Output:
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
EMPNO ENAME
---------- ----------
7782 CLARK
7839 KING
7934 MILLER
20 RESEARCH DALLAS
EMPNO ENAME
---------- ----------
7369 SMITH
7566 JONES
7788 SCOTT
7876 ADAMS
7902 FORD
30 SALES CHICAGO
EMPNO ENAME
---------- ----------
7499 ALLEN
7521 WARD
7654 MARTIN
7698 BLAKE
7844 TURNER
7900 JAMES
6 rows selected.
40 OPERATIONS BOSTON
no rows selected
creating emp and dept tables::
CREATE TABLE DEPT (
DEPTNO NUMBER(2) NOT NULL,
DNAME VARCHAR2(14),
LOC VARCHAR2(13));
INSERT INTO DEPT VALUES (10,'ACCOUNTING','NEW YORK');
INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS');
INSERT INTO DEPT VALUES (30,'SALES','CHICAGO');
INSERT INTO DEPT VALUES (40,'OPERATIONS','BOSTON');
CREATE TABLE EMP (
EMPNO NUMBER(4) NOT NULL,
ENAME VARCHAR2(10),
JOB VARCHAR2(9),
MGR NUMBER(4),
HIREDATE DATE,
SAL NUMBER(7,2),
COMM NUMBER(7,2),
DEPTNO NUMBER(2) NOT NULL);
INSERT INTO EMP VALUES (7839,'KING','PRESIDENT',NULL,TO_DATE('17-NOV-1981','DD-MON-YYYY'),5000,NULL,10);
INSERT INTO EMP VALUES (7698,'BLAKE','MANAGER',7839,TO_DATE('1-MAY-1981','DD-MON-YYYY'),2850,NULL,30);
INSERT INTO EMP VALUES (7782,'CLARK','MANAGER',7839,TO_DATE('9-JUN-1981','DD-MON-YYYY'),2450,NULL,10);
INSERT INTO EMP VALUES (7566,'JONES','MANAGER',7839,TO_DATE('2-APR-1981','DD-MON-YYYY'),2975,NULL,20);
INSERT INTO EMP VALUES (7654,'MARTIN','SALESMAN',7698,TO_DATE('28-SEP-1981','DD-MON-YYYY'),1250,1400,30);
INSERT INTO EMP VALUES (7499,'ALLEN','SALESMAN',7698,TO_DATE('20-FEB-1981','DD-MON-YYYY'),1600,300,30);
INSERT INTO EMP VALUES (7844,'TURNER','SALESMAN',7698,TO_DATE('8-SEP-1981','DD-MON-YYYY'),1500,0,30);
INSERT INTO EMP VALUES (7900,'JAMES','CLERK',7698,TO_DATE('3-DEC-1981','DD-MON-YYYY'),950,NULL,30);
INSERT INTO EMP VALUES (7521,'WARD','SALESMAN',7698,TO_DATE('22-FEB-1981','DD-MON-YYYY'),1250,500,30);
INSERT INTO EMP VALUES (7902,'FORD','ANALYST',7566,TO_DATE('3-DEC-1981','DD-MON-YYYY'),3000,NULL,20);
INSERT INTO EMP VALUES (7369,'SMITH','CLERK',7902,TO_DATE('17-DEC-1980','DD-MON-YYYY'),800,NULL,20);
INSERT INTO EMP VALUES (7788,'SCOTT','ANALYST',7566,TO_DATE('09-DEC-1982','DD-MON-YYYY'),3000,NULL,20);
INSERT INTO EMP VALUES (7876,'ADAMS','CLERK',7788,TO_DATE('12-JAN-1983','DD-MON-YYYY'),1100,NULL,20);
INSERT INTO EMP VALUES (7934,'MILLER','CLERK',7782,TO_DATE('23-JAN-1982','DD-MON-YYYY'),1300,NULL,10);
|
|
|
|
|
Have you considered doing your own homework ?
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
|
|
|
|
|
I ALREADY SOLVED 2 PROBLEMS AND THOSE ARE THE REMAINNING 2 QUESTIONS
NO BODY SLVED THOSE TWO QUESTIONS
|
|
|
|
|
I'm not sure how that is relevant. Neither question is particularly hard, and the core point is that if you don't take the time to do your homework when it's relatively easy, how will you cope as it gets harder, and you've become accustomed to asking strangers to do it for you ?
If you had posted your attempt and asked for help, I'd have been glad to help, but no-one here is going to do your homework for you.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
|
|
|
|
|
I DONT KNOW WHY YOU ARE YOU TALKING TOO MUCH
BUT I AM TRYING TO SOLVE IT FOR MORE THAN TWO WEEKS AND I TRIED SEVERAL WAYS
HERE IS THE MOST RECENT WAYS BUT IT DIDNT WORK:
SELECT DISTINCT D.DEPTNO, D.DNAME, D.LOC,
(SELECT E1.EMPNO FROM EMP E1 WHERE E1.DEPTNO = 10) Dept_10,
(SELECT E2.EMPNO FROM EMP E2 WHERE E2.DEPTNO = 20) Dept_20,
(SELECT E3.EMPNO FROM EMP E3 WHERE E3.DEPTNO = 30) Dept_30
FROM DEPT D, EMP E
WHERE E.DEPTNO = D.DEPTNO;
AND I WILL TRY TO FIND MY OTHER ATTEMPTS AND PUT IT FOR YOU
I WANT TO KNOW HOW COME IT IS VERY SIMPLE QUESTIONS?
FOR YOUR INFO WE ARENT TEACHED THE SQL STATEMENTS BUT WE ARE STUDYING THE DATA MODELING AND OTHER STAFF AND WE HAVE TO LEARN SQL OURSELF.SO DONT THINK WE ARE EXPERTS OR EVEN STUDENTS OF SQL, WE ARE ONLY SELF-LEARNNING STUDENTS.
I'V WENT TO THE COMPLETE DOCUMENTATION OF THE SQL BUT I DIDNT FIND THE CORRECT FUNCTIONS TO USE!!
|
|
|
|
|
i have this questions that i need help in solving it or at least a hint
please......................  
i hope you cn help me solve it...
Write down single SQL statement to display currency (salary) in words without using any direct function. e.g:
EMPNO ENAME SAL Salary in words
---------- ---------- -------- ---------------
7369 SMITH 800 Eight hundred
7499 ALLEN 1600 One thousands and six hundred
7521 WARD 1250 One thousands, two hundred and fifty
|
|
|
|
|
THESE OUR VERSION OF THE SOLUTION BUT IT DIDNT FULLY MEET THE REQUIRMENTS
BECAUSE AS YOU SEE IT MUST CONTAIN THE COMMA(,) AFTER THE thousands IF THERE IS TENS AFTER THE hundredS ANS AN (AND) BEFORE THE hundredS AND IT SHOULD CONTAIN AN (AND) AFTER THE thousands IF THERE IS NO TENS AFTER THE hundredS
IF YOU DIDNT UNDERSTAND ME YOU CAN COMPARE THE OUTPUT OF MY QUERY BELOW AND THE OUTPUT OF THE EXAMPLE OF THE FIRST THREAD:
SELECT EMPNO, ENAME, SAL, TO_CHAR(TO_DATE(TO_CHAR(SAL),'YYYY'), 'YEAR') SALARY
FROM EMP
ORDER BY EMPNO;
|
|
|
|
|
I am aware that ADO.Net transaction mechanism is the same as SQL Server.
My question is does is make any difference on handling transaction by ADO.net or directly on SQL Server database.
Is either of two better then other? in short SQL Transaction vs ADO.Net Transaction. 
ketty
|
|
|
|
|
Hi,
I have bought some space on MS SQL server to host my site. the company has asked for IP address that will be accessing the server.
My question is what IP addresses do I need to provide them:
Is it the IP address of my local machine?
Is it the IP address of my web site?
Any ideas??
|
|
|
|
|
hasanali00 wrote:
IP address that will be accessing the server
I think you've answered your own question. It is the IP address of the machine that you will be using to access the server. I'm assuming that the web application will be hosted by this company also, so the IP address of the web site will be internal to them. The other IP address, the one you provide, must therefore be the one you have for administrative access - i.e. the IP address of the machine you will be using to administer the account.
DISCLAIMER: This is mostly based on a set of assumptions, whether stated or otherwise, that may or may not be correct. If you need clarity you MUST go back to your hosting service provider and ask them what they mean.
Do you want to know more?
Vogon Building and Loan advise that your planet is at risk if you do not keep up repayments on any mortgage secured upon it. Please remember that the force of gravity can go up as well as down.
|
|
|
|
|
|
I'm writing a new database driven application. In one of my stored procedures, I want to add user data and get back user id from table.
The table has this structure:
ID, numeric, identity with identity seed =1,
username, char(25)
email, char(40)
my stored procedure looks like this:
ALTER PROCEDURE dbo.InsertNewUser
(
@UserName char(25),
@email char(40),
@ID numeric OUTPUT
)
AS
INSERT INTO Users
(UserName, email)
VALUES (@UserName, @email);
RETURN
How I changed the stored procedure to return the new added user's ID?
I code in C#.
Best regards,
A. Riazi
|
|
|
|
|
If this is SQL Server 2000:
SET @ID = SCOPE_IDENTITY() If SQL Server 7.0, you have to use the @@IDENTITY variable; however, this may produce incorrect results if a trigger fires which inserts rows.
Stability. What an interesting concept. -- Chris Maunder
|
|
|
|
|
|
How do we retreive data from SQL database. Could anyone please explain in VB.net with a small example from database connection to databinding and retreiving the data in web application
|
|
|
|
|
This is an absolute beginner question - you should try reading the site at large and/or MSDN before asking a question like this. There is tons of info online.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
|
|
|
|
|
I guess time matters. There are only code snippets on simple data binding but not in complex data binding. Because i was unable to find it i have asked this question.
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
