SQL Query - Delete All Rows Bar The Last 10? Help Please!
Jan 6, 2008
Hi,
I'm really not very good at SQL sadly, so would really appreciate any help.
I'm basically working on a website that has a chatroom. I want it so the chatroom table only holds, say 15 lines of chat, then once a new line of chat is entered the last line in the table is deleted, so the table always has a maximum of just 15 rows.
The fields are:
MessageID
Poster
Message
DateTime
I've tried my best, but just don't know how to do it.
I suppose it's something like:
SELECT TOP 15 * FROM Chatroom ORDER BY MessageID DESC - this gives me the last 15 rows.
Then I need a delete statement to delete the rest?! Sorry, I am very bad at SQL, so any help would be great. This is written in a stored procedure.
Can the stored procedure pick up whether there are 15 or more rows in the table, and if so then delete all bar the newest 15 rows of chat?
To summarise: I want a stored procedure that checks if 15 or more rows exist, if they do then delete all bar the newest 15 rows.
I'm using SqlDataSource and an Access database. Let's say I got two tables:user: userID, usernamemessage: userID, messagetextLet's say a user can register on my website, and leave several messages there. I have an admin page where I can select a user and delete all of his messages just by clicking one button.What would be the best (and easiest) way to make this?Here's my suggestion:I have made a "delete query" (with userID as parameter) in MS Access. It deletes all messages of a user when I type in the userID and click ok.Would it be possible to do this on my ASP.net page? If yes, what would the script look like?(yes, it is a newbie question)
I ran the following query in Query Analyzer on a machine running SQL Server 2000. I'm attempting to delete from a linked server running SQL Server 2005:
DELETE FROM sql2005.production.dbo.products WHERE vendor='Foo' AND productId NOT IN ( SELECT productId FROM sql2000.staging.dbo.fooProductList )
The status message (and @@ROWCOUNT) told me 8 rows were affected, but nothing was actually deleted; when I ran a SELECT with the same criteria as the DELETE, all 8 rows are still there. So, once more I tried the DELETE command. This time it told me 7 rows were affected; when I ran the SELECT again, 5 of the rows were still there. Finally, after running this exact same DELETE query 5 times, I was able to remove all 8 rows. Each time it would tell me that a different number of rows had been deleted, and in no case was that number accurate.
I've never seen anything like this before. Neither of the tables involved were undergoing any other changes. There's no replication going on, or anything else that should introduce any delays. And I run queries like this all day, involving every thinkable combination of 2000 and 2005 servers, that don't give me any trouble.
Does anyone have suggestions on what might cause this sort of behavior?
I had created a trigger which sees that whether a database is updated if it is its copy the values of the updated row into another control table now I want to read the content of control_table into BIzTalk and after reading I want to delete it.Can any one suggest the suitable ay to do this?
I have a SQL script to insert data into a table as below:
INSERT into [SRV1INS2].BB.dbo.Agents2 select * from [SRV2INS14].DD.dbo.Agents
I just want to set a Trigger on Agents2 Table, which could delete all rows in the table , before carry out any Insert operation using above statement.I had below Table Trigger on [SRV1INS2].BB.dbo.Agents2 Table as below: But it did not perform what I intend to do.
USE [BB] GO /****** Object: Trigger Script Date: 24/07/2015 3:41:38 PM ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON
Stepping thru the code with the debugger shows the dataset rows being deleted.
After executing the code, and getting to the page presentation. Then I stop the debug and start the page creation process again ( Page_Load ). The database still has the original deleted dataset rows. Adding rows works, then updating works fine, but deleting rows, does not seem to work.
The dataset is configured to send the DataSet updates to the database. Use the standard wizard to create the dataSet.
cDependChildTA.Fill(cDependChildDs._ClientDependentChild, UserId); rowCountDb = cDependChildDs._ClientDependentChild.Count; for (row = 0; row < rowCountDb; row++) { dr_dependentChild = cDependChildDs._ClientDependentChild.Rows[0]; dr_dependentChild.Delete(); //cDependChildDs._ClientDependentChild.Rows.RemoveAt(0); //cDependChildDs._ClientDependentChild.Rows.Remove(0); /* update the Client Process Table Adapter*/ // cDependChildTA.Update(cDependChildDs._ClientDependentChild); // cDependChildTA.Update(cDependChildDs._ClientDependentChild); } /* zero rows in the DataSet at this point */ /* update the Child Table Adapter */ cDependChildTA.Update(cDependChildDs._ClientDependentChild);
this is my Delete Query NO 1 alter table ZT_Master disable trigger All Delete ZT_Master WHERE TDateTime> = DATEADD(month,DATEDIFF(month,0,getdate())-(select Keepmonths from ZT_KeepMonths where id =1),0) AND TDateTime< DATEADD(month,DATEDIFF(month,0,getdate()),0) alter table ZT_Master enable trigger All
I have troble in Delete Query No 2 here is a select statemnt , I need to delete them select d.* from ZT_Master m, ZT_Detail d where (m.Prikey=d.MasterKey) And m.TDateTime> = DATEADD(month,DATEDIFF(month,0,getdate())-(select Keepmonths from ZT_KeepMonths where id =1),0) AND m.TDateTime< DATEADD(month,DATEDIFF(month,0,getdate()),0) I tried modified it as below delete d.* from ZT_Master m, ZT_Detail d where (m.Prikey=d.MasterKey) And m.TDateTime> = DATEADD(month,DATEDIFF(month,0,getdate())-(select Keepmonths from ZT_KeepMonths where id =1),0) AND m.TDateTime< DATEADD(month,DATEDIFF(month,0,getdate()),0) but this doesn't works..
can you please help? and can I combine these 2 SQL Query into one Sql Query? thank you
Hi All,I am designing a purge process for a db that has grown to almost 200GB.My purge process will remove about 1/3 of the 500 million rows spreadover seven tables. Currently there are about 35 indexes defined onthose seven tables. My question is will there be a performance gain bydropping those indexes, doing my purge, and re-creating the indexes. Iam afraid that leaving those indexes in place will create a lot ofextra overhead in my delete statements by having to maintain theindexes. I know that it could take many hours to rebuild the indexesafterward, but I am planning on doing that anyway. The reason that Iwant to know whether I should drop the indexes ahead of time, is I maynot be able to do the entire purge at once and the tables may need tobe accessed between purges. If this occurs, I will need to have thoseindexes in place.So do I drop the indexes before the purge and re-create them later ordo I leave them in place and re-index them afterward?Thanks In Advancep.h.
there are 500000 rows that has projektID=5.. and when i run the query the hardrive is working for a couple of minutes and then stops. and NOTHING has happened. not a single row has been deleted?.. cant the DELETE statement handle that many rows or?. or is there another way i can delete these rows?.
Hii want to delete a row in my database but the problem is, i cant delete it as other table rows is linked to it. I have to delete all the rows thats linked to the row i wanna delete first.Is there a easier way to delete the row and all the rows thats linked to it? i wanna code it to do it.an suggestions?
CAN ANYBODY REPLY FOLLOWING QUESTIONS. I WANT TO DELETE DUPLICATE ROWS IN MY TABLE WITHOUT USING TRANSACTION TABLE. AND ONE MORE QUESTION HOW TO GET YESTERDAY DATE BY USING ISQL WINDOW.
In my table I have following current data. I want to delete duplicate records from table.I am trying following SQL statement, So I am getting desired output which is orange color in current data. I want to keep the desired output records and other all should be deleted. But complection is that in current data values in C5 and C6 are different.
select C1,C2,C3,C4,COUNT(*) from table_Delete group by C1,C2,C3,C4 having COUNT(*) >= 1 ORDER BY COUNT(*) DESC
declare @a1 table (id int not null identity(1,1), phone decimal(18,0), adress nvarchar(100)) insert @a1 (phone,adress)
[Code] ....
id phone address ----------- --------------------------------------- ---------------------------------------------------------------------------------------------------- 1 111 new york 2 111 new york 3 111 new york 4 222 maxico 5 222 mexico
select phone,count(phone) as say from @a1 group by phone having count(phone)>1
phone say --------------------------------------- ----------- 111 3 222 2
How can I remove duplicate phone. For example
after delete select*from @a1 select*from @a1
id phone address ----------- --------------------------------------- ---------------------------------------------------------------------------------------------------- 1 111 new york 4 222 maxico
I wrote this to show for example in my real table have 50000 rows and 1751 duplicate rows.
Hi,I need to delete rows from my user tables dependant upon there nonexistence from another table:delete studentwhere student_id not in (select student_id from tblStudent)The reasons is convoluted, simplest explanation is that our operationalsystem allows the change of business keys. This wreaks havoc in thedata warehouse.So, I'm look for help on how I can delete rows from tables that have acolumn STUDENT_ID. I'd like the script to search for the tables, thenperform the delete.I don't know where information about user tables are stored, nor how toloop through the results to do the delete.Any Ideas are appreciated.
hi.I've seen ways to delete duplicate rows.Can someone give me some sql to do this?I have a table with varchar table_name_start, varchar column_name,varchar table_name_end;it has rows like this:table1 col1 table2table1 col2 table 3table2 col1 table1I'd lke to delete the rows if they exist with the names swappedaround, i.e. like above since the first and third share a column nameand the table_name_start/end matches the others table_name_end/start,I'd like to delete one and leave the other.I'm scratching my head trying to figure this out.thanks
hi alli hava eetable that is ,eename sal_______ ________suresh 100000ramsesh 100000raja 100000susjssj 100000dkddkd 100000jfdjfdjfd 100000so i want to delete from second to Fourth row by using Rownumber..Rownumber is not a column of eetable give some example
I have a Foreach loop container where I populate a Ado recordset with some ids. Then I use another Foreach loop container to shred the Recordset and perform some task. Once Second Foreach Loop container is completed, my Recordset is getting populated again by the parent Foreach loop, except it is not discarding the data from before. Is there a way I can reset or delete rows from recordset after my second Foreach Loop container so that I don't duplicate rows in the Recordset.
hi everyone ,How are you all? i'm working on sql DTS to transfer data from oracle to MS SQL2000 i did the transfer but i need to delete transfered data from oracle in DTS How i could do that?
I have a table in which i have to delete last n inserted rows, how should i approach this , Sql server does not provide any ROWGUID BASED ON TIMESATAMP i dnt think Rank() wil work either Any suggestions?
