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Hi
I had a question abt the Inconsistent Read concurency issue with my application's data access that I am currently developing. Here is my problem. I am using custom business objects that represent my database entities. For example, in one of the web pages displays a list of users in a datagrid bindng it to customcollection that holds user objects (instance of my user class). I am using Enteprise Library to do my dataccess. my DAL would read the data from the database (makes a call to the store procedure) and pass the custom collection of user objects to the UI. When the user clicks on any row of the displayed list, it takes himt o another page that displays further details of that particular user and he may update them. Do I need to use any lock options while reading the data from the database? I mean optimistic concurrency control?
Any suggestions would be greatly appreciated...Please help.
Thanks
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I am pretty much exclusively using SqlDataAdapter.Fill method.... I am getting the dreaded timeout connection pool limit exceeded. MSDN tells me I dont have to exclusively open and close my connections. Yet! under heavy use, i'm getting these errors in my application. What can I do to make sure these connections are getting closed using this method.
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I use
finally block to make sure that clean up is performed
Farhan Noor Qureshi
if (this == this) thow this;
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I am trying to combine several columns from one table: The First Name, Last Name, Middle Name, City, State. I want to Combine the first, last, and middle names and then have a varying amount of spaces between it and the city and state. All of these will be combined into one column and displayed in a listbox. For Example:
Problem:
John Smith Los Angeles, CA
Johnathan Smith Los Angeles, CA
Solution: HOW!
John Smith Los Angeles, CA
Johnathan Smith Los Angeles, CA
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Asuuming all are varchar or char(n)
select FirstName + ' ' + LastName + ' ' + MiddleName + ' ' + City + ' ' + State
from yourtable.
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You might wanna check for null, b/c if any of the field is NULL then the resultant is NULL. Use TSQL function IsNull() function.
Farhan Noor Qureshi
if (this == this) thow this;
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Hi,
I have some code where the dataset being modified is the result of a JOIN between two tables. The key of the first table is also a foreign key of the second table. There will be situations where the fields from the second table will be NULL and others when the alternate key on table two will match the primary key of table one.
The record binding code works when the alternate key is not NULL, but when it and the second tables fields are NULL then the UpdateBatch gives the error "Row cannot be located for updating. Some values may have been changed since it was last read."
This is not true as this is a) not a multi-user system and b) nothing has changed.
I have dumped all the values in the record set - Value, OriginalValue and UnderlyingValue. All the fields of the second table are showing up as NULL for all of the value types.
All the other fields values are identical apart from Value for the attribute on the first table being updated.
I have status values for all the fields from the second table and they are all set to adFldNull.
If I then swap to using the Collect method then no error occurs.
The connection has the following properties:
Provider = oledb (Server is SQL Server 2000)
CursorLocation = adUseClient
IsolationLevel = adXactReadCommitted
ConnectionMode = adModeRead | adModeWrite | adModeShareDenyRead |
adModeShareDenyWrite | adModeShareExclusive
The recordset properties are:
CursorLocation = adUseClient
CursorType = adOpenStatic
LockType = adLockBatchOptimistic
MarshalOptions = adMarshalModifiedOnly
Any ideas other than swapping to using the Collect method?
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Can we restart the counter in SQL Server
If we can, how can we do it
Thanks
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What counter?
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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It's AutoIncrement Field
Thanks
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Well, AFAIK, you can set the IDENTITY_INSERT ON and then let say your max ID is 10 so if you want to set it back to 1, set the seed to -9, and set the seed back to 1.
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hello,
i have a question: i do a SELECT on a .mdb file. i want to get the no of rows in the rowset. SQLRowCount won't work - 'cos I've made a select.
i don't wanna fetch all rows and set a counter.
is there any way? i've tried:
retcode = SQLExtendedFetch(hStmt, SQL_FETCH_LAST, 0, &lRow, &lStatus);
//this goes ok
SQLGetStmtAttr(hStmt, SQL_ATTR_ROW_NUMBER, &noOfRows, SQL_IS_INTEGER, NULL);
printf("total:%ld, \n",noOfRows);
//this NOT!! it's 0.
i think there must be a way - anyway i must complain about ODBC's lack of *good* documentation.
thanks
Cristian
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Example: I want to display a table from a database with one single column (authors_last_names) in a GridView. This table contains 18 entries. But I want them to be spread over 2 columns in the GridView, which means either the first column displays the first ten last names and the second one the other 8, or both columns show nine last names.
How can i do this?
Thanks a lot
Stefan
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Hi,
I need to implement some function like, when the database is updated through one page, the other page, which is listing all the records, should be refreshed automatically and display newly updated recordset.
I was thinking using trigger. But it seems that it only can update tables within the database itself.
How to trigger the browser to reload and keep the data on the page updated?
Can anyone give some ideas?
Thanks in advance!
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I have been tasked with moving all of the SQL Server databases from an old server to a new one.
I was hoping to simply do a sp_detach, copy the mdf & ldf files to the new server, then reattach them. However, we are using mix-mode authentication and the handful of sql user logins we use fail to login on the new server during testing. So, I attempted to create the users under the security/logins section prior to attaching the database but, that did not work either. Is there an easy/fast way to migrate the database to the new server with out using DTS?
Application Error Log File which probably isn't helpful:
SQL Errors:
SqlError: 1
Error #: 4060
Procedure:
Line # 0
Server: TheSqlServer
Source: .Net SqlClient Data Provider
Message: Cannot open database requested in login 'TheDatabase'. Login fails.
SqlError: 2
Error #: 18456
Procedure:
Line # 0
Server: TheSqlServer
Source: .Net SqlClient Data Provider
Message: Login failed for user 'SqlServerLogin'.
Thanks,
Michael
I firmly believe that any man's finest hour, the greatest fulfillment of all that he holds dear, is that moment when he has worked his heart out in a good cause and lies exhausted on the field of battle - victorious.
Vince Lombardi (1913-1970)
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in the database list, right click -> all tasks -> generate sql script...
With this, you can select that Enterprise Manager creates scripts for the users using the database, try it.
daniero
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I have a application that has is develop using c#
B4 this all my data processing is done thourgh the tsql statment, now i want to switch the thing to stored procedure..
1.) but my management wnt to know is they any way we can hide the code in stored from the database administrator like the 1 in the trigger where we can encrypt the trigger..
2.) one more thing can we populate the stored procedure from c#..
so every update i will create 1 EXE for them to run and i will update the stored procedure without using any sql util...
thanks...
Jalil
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Abdul Jalil Mohamed wrote: is they any way we can hide the code in stored from the database administrator like the 1 in the trigger where we can encrypt the trigger..
Yes, you can encrypt stored procedures
Abdul Jalil Mohamed wrote: i will create 1 EXE for them to run and i will update the stored procedure without using any sql util
Yes, you can create an exe that runs SQL against the database. You can do this by using the SqlCommand object in a .NET application and then ExecuteNonQuery()
I have an example on my blog where the SQL Script is stored as a resource inside an EXE file then run against the database. You might find it useful: http://blogs.wdevs.com/colinangusmackay/archive/2004/10/15/857.aspx[^]
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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1.) use WITH ENCRYPTION statement before
AS
--Stored procedure statements
Do make sure to have a backup of the stored procedure somewhere since, you're not going to see that text once you applay the statement and close the editor.
2.) you can... create stored procedures from C#... theoretically yes, you can execute a SQL command with a CREATE PROCEDURE statement, and then use the SP.
daniero
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daniero wrote: theoretically yes
It is not a theory, it is a fact. You can do this so long as you log on to the database as a user with ddl_admin, db_onwer or sysadmin privileges.
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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Thanks for clearing that up. I need to write it down   .
daniero
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I have a vb.net application that:
Loops through a list of tables (could be up to 1000 tables)
Extracts all records in the table writes them to a datareader
Opens a connection to a different odbc data source and creates a dataset with a table with the same name as the tables in the loop
Uses newrow to create a new row
Updates data common to all tables ( a companyid)
Uses row.add to add the row to the table
At this stage all columns in the row appear to be populated correctly.
However when I do dataadapter.update() All rows are added to the source table but only the primary key is populated.
I've used commandbuilder.getinsertcommand to see what insert string is being used and the insert is only trying to insert the primary key (3 columns)
Datasource is a Progress database (Version 10b)
Using ODBCDataadapter to read and write the data.
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DataAdapter and CommandBuilder are not the best objects to use for this. You need to learn how to write your own insert commands as .NET will not write efficient commands for you - most of the time I will create slow commands that guarantee the right result but only because they act by brute force.
Create your own command object giving it an INSERT command that you define. You can then call ExecuteNonQuery() to insert the row. This will also be faster.
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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Colin, Thank you for the feedback
I was hoping to use the automatically generated insert command for the following reasons:
It's possible that it will processing over 1000 different tables
Some of these tables contain approx 140 columns
I don't have control over the database so I won't necessarily know when changes are made
I can't add stored procedures to the database to do the inserts
I suppose I could use code to build the command in another loop - but I was hoping to avoid this
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