I am new to SQL, especially use SQL in VC++ 6.0 framework.
I am told that creating INDEX on field(s) could speed up a query.
if I create a INDEX like the following
<code>
CREATE nonclustered INDEX IX_XYZ on TableA.field1
</code>
Should I use the INDEX name IX_XYZ in some way in the following SELECT statement. Or the following SELECT statement will be carried out automatically based on the INDEX IX_XYZ.
<code>
SELECT * FROM TableA WHERE field1 = xxx
</code>
One of the major syntax inside the SELECT statment is ..
WHERE FIELDA IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='A') AND WHERE FIELDB IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='B') AND WHERE FIELDC IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='C') AND WHERE FIELDD IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='D') AND WHERE FIELDE IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='E') AND WHERE FIELDF IN (SELECT PARAVALUE FROM PARATABLE WHERE SESSIONID = "XXXXX" AND PARATYPE='F')
(It's to compare the field content with some user input parameter inside a parameter table... )
I think properly is that the SELECT ... IN is causing much slowness in the sql statement. I have indexed FIELDA , FIELDB, FILEDC etc and those PARAVALUE and PARATYPE in the PARATABLE table. But perfromance is still slow and execution takes >20 seconds for 200000 rows of records.
Do any one know if still any chance to improvide the performance like this?
hello friends i have table1 and 200 coulumn of table1 :) i have 647.600 records. i entered my records to table1 with for step to code lines in one day :) i select category1 category2 and category3 with select code but i have just one index.. it is productnumber and it is primarykey..So my select code lines is so slow.. it is 7-9 second.. how can i select in 0.1 second ? Should i create index for category1 and category2 and category3 ? But i dont know create index.. My select code lines is below.. Could you learn me and show me index for it ?? or Could you learn me and show me fast Select code lines and index or etc ??? Also my search code line have a dangerous releated to attaching table1 with hackers :) cheersi send 3 value of treview1 node and childnode and child.childnode to below page.aspx :) Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not Me.IsPostBack Then If Request("TextBox1") IsNot Nothing ThenTextBox1.Text = Request("TextBox1") End If If Request("TextBox2") IsNot Nothing ThenTextBox2.Text = Request("TextBox2") End If If Request("TextBox3") IsNot Nothing ThenTextBox3.Text = Request("TextBox3") End If End If Dim searchword As String If Request("TextBox3") = "" And Request("TextBox2") = "" Then searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "'" End If If Request("TextBox3") = "" Then searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "' and kategori1= '" & Request("TextBox2") & "'" End If If Request("TextBox3") <> "" And Request("TextBox2") <> "" And Request("TextBox1") <> "" Then searchword = "Select * from urunlistesi where kategori= '" & Request("TextBox1") & "' and kategori1= '" & Request("TextBox2") & "' and kategori2= '" & Request("TextBox3") & "'" End If SqlDataSource1.SelectCommand = searchword End Sub
I am currently having this problem with gridview and detailview. When I drag either onto the page and set my select statement to pick from one table and then update that data through the gridview (lets say), the update works perfectly. My problem is that the table I am pulling data from is mainly foreign keys. So in order to hide the number values of the foreign keys, I select the string value columns from the tables that contain the primary keys. I then use INNER JOIN in my SELECT so that I only get the data that pertains to the user I am looking to list and edit. I run the "test query" and everything I need shows up as I want it. I then go back to the gridview and change the fields which are foreign keys to templates. When I edit the templates I bind the field that contains the string value of the given foreign key to the template. This works great, because now the user will see string representation instead of the ID numbers that coinside with the string value. So I run my webpage and everything show up as I want it to, all the data is correct and I get no errors. I then click edit (as I have checked the "enable editing" box) and the gridview changes to edit mode. I make my changes and then select "update." When the page refreshes, and the gridview returns, the data is not updated and the original data is shown. I am sorry for so much typing, but I want to be as clear as possible with what I am doing. The only thing I can see being the issue is that when I setup my SELECT and FROM to contain fields from multiple tables, the UPDATE then does not work. When I remove all of my JOIN's and go back to foreign keys and one table the update works again. Below is what I have for my SQL statements:------------------------------------------------------------------------------------------------------------------------------------- SELECT:SELECT People.FirstName, People.LastName, People.FullName, People.PropertyID, People.InviteTypeID, People.RSVP, People.Wheelchair, Property.[House/Day Hab], InviteType.InviteTypeName FROM (InviteType INNER JOIN (Property INNER JOIN People ON Property.PropertyID = People.PropertyID) ON InviteType.InviteTypeID = People.InviteTypeID) WHERE (People.PersonID = ?)UPDATE:UPDATE [People] SET [FirstName] = ?, [LastName] = ?, [FullName] = ?, [PropertyID] = ?, [InviteTypeID] = ?, [RSVP] = ?, [Wheelchair] = ? WHERE [PersonID] = ? ---------------------------------------------------------------------------------------------------------------------------------------The only fields I want to update are in [People]. My WHERE is based on a control that I use to select a person from a drop down list. If I run the test query for the update while setting up my data source the query will update the record in the database. It is when I try to make the update from the gridview that the data is not changed. If anything is not clear please let me know and I will clarify as much as I can. This is my first project using ASP and working with databases so I am completely learning as I go. I took some database courses in college but I have never interacted with them with a web based front end. Any help will be greatly appreciated.Thank you in advance for any time, help, and/or advice you can give.Brian
Ok I have a query "SELECT ColumnNames FROM tbl1" let's say the values returned are "age,sex,race".
Now I want to be able to create an "update" statement like "UPATE tbl2 SET Col2 = age + sex + race" dynamically and execute this UPDATE statement. So, if the next select statement returns "age, sex, race, gender" then the script should create "UPDATE tbl2 SET Col2 = age + sex + race + gender" and execute it.
hiI need to write a stored procedure that takes input parameters,andaccording to these parameters the retrieved fields in a selectstatement are chosen.what i need to know is how to make the fields of the select statementconditional,taking in consideration that it is more than one fieldaddedfor exampleSQLStmt="select"if param1 thenSQLStmt=SQLStmt+ field1end ifif param2 thenSQLStmt=SQLStmt+ field2end if
Code Block SELECT DISTINCT Field01 AS 'Field01', Field02 AS 'Field02' FROM myTables WHERE Conditions are true ORDER BY Field01
The results are just as I need:
Field01 Field02
------------- ----------------------
192473 8461760
192474 22810
Because other reasons. I need to modify that query to:
Code Block SELECT DISTINCT Field01 AS 'Field01', Field02 AS 'Field02' INTO AuxiliaryTable FROM myTables WHERE Conditions are true ORDER BY Field01 SELECT DISTINCT [Field02] FROM AuxTable The the results are:
Field02
----------------------
22810 8461760
And what I need is (without showing any other field):
Field02
----------------------
8461760 22810
Is there any good suggestion? Thanks in advance for any help, Aldo.
Hello friends, I want to use select statement in a CASE inside procedure. can I do it? of yes then how can i do it ?
following part of the procedure clears my requirement.
SELECT E.EmployeeID, CASE E.EmployeeType WHEN 1 THEN select * from Tbl1 WHEN 2 THEN select * from Tbl2 WHEN 3 THEN select * from Tbl3 END FROM EMPLOYEE E
can any one help me in this? please give me a sample query.
Clearly, a non clustered index can improve the performance of a SELECT statement. Is the same true with an INSERT statement? My contention is that the use of a non clustered index will hurt the performace of an insert statement.
I have 3 tables, with this relation: tblChats.WebsiteID = tblWebsite.ID tblWebsite.AccountID = tblAccount.ID
I need to delete rows within tblChats where tblChats.StartTime - GETDATE() < 180 and where they are apart of @AccountID. I have this select statement that works fine, but I am having trouble converting it to a delete statement:
SELECT * FROM tblChats c LEFT JOIN tblWebsites sites ON sites.ID = c.WebsiteID LEFT JOIN tblAccounts accounts on accounts.ID = sites.AccountID WHERE accounts.ID = 16 AND GETDATE() - c.StartTime > 180
Hey guys i have a stock table and a stock type table and what i would like to do is say for every different piece of stock find out how many are available The two tables are like thisstockIDconsumableIDstockAvailableconsumableIDconsumableName So i want to,Select every consumableName in my table and then group all the stock by the consumable ID with some form of total where stockavailable = 1I should then end up with a table like thisEpson T001 - Available 6Epson T002 - Available 0Epson T003 - Available 4If anyone can help me i would be very appreciative. If you want excact table names etc then i can put that here but for now i thought i would ask how you would do it and then give it a go myself.ThanksMatt
SELECT Top 10 Name, Contact AS DCC, DateAdded AS DateTimeFROM NameTaORDER BY DateAdded DESC I'm trying to right a sql statement for a gridview, I want to see the last ten records added to the to the database. As you know each day someone could add one or two records, how can I write it show the last 10 records entered.
Hello How can i say this I would like my if statement to say: if what the client types in Form1.Cust is = to the Select Statement which should be running off form1.Cust then show the Cust otherwise INVALID CUSTOMER NUMBER .here is my if statement. <% If Request.Form("Form1.Cust") = Request.QueryString("RsCustNo") Then%> <%=Request.Params("Cust") %> <% Else %> <p>INVALID CUSTOMER NUMBER</p> <% End If%> <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:RsCustNo %>" ProviderName="<%$ ConnectionStrings:RsCustNo.ProviderName %>" SelectCommand="SELECT [CU_CUST_NUM] FROM [CUSTOMER] WHERE ([CU_CUST_NUM] = ?)"> <SelectParameters> <asp:FormParameter FormField="Cust" Name="CU_CUST_NUM" Type="String" /> </SelectParameters> </asp:SqlDataSource>any help would be appreciated
Hi,I am making as SELECT query to fill a repeater, and I need to retrieve the index of each line of the query.ie, I want to get a dataset like :"0", "dataCol1", "dataCol2" for the first line"1", "dataCol1", "dataCol2" for the second line"2", "dataCol1", "dataCol2" for the third lineetc.Anyone knows if there is a sql statement that does it ?ThanksJohann
the following will work if I want to have UNIQUE Users.Name >> INSERT INTO [Users] (Name) SELECT Names FROM OtherUsers where OtherUsers.Names not in (select Name from Users)
but if I have an UNIQUE INDEX on Users CREATE UNIQUE INDEX [IX_Users] ON [Users] ([Name],[Category]) ON [PRIMARY] how can I do it ?
INSERT INTO [Users] (Name, Category) SELECT Names,Categories FROM OtherUsers where OtherUsers.Names + OtherUsers.Categories not in (select Name, Category from Users) ?
how can I insert it wih an index on 2 or 3 columns ?
Eliko writes "i would like to add a coloumn to a select result, so there will be another coloumn with indexed running numbers for each record. how can i do it?
I want to Select a value from a Column which is named "Index" - and I don't want to change the name naturally. Is there a way to get a value without mentioning the Column name itself, rather the column number? "Incorrect syntax near 'Index'. If this is intended as a part of a table hint, A WITH keyword and parenthesis are now required. See SQL Server Books Online for proper syntax."
Occurs when I try to simply.. -> SELECT Index FROM Table WHERE Name like 'xyz' <-
I understand that minimal logging can occur on a non clustered indexed heap as long as [URL] ...
*not replicated
*tablock is used
*table is empty
The following test seems to contradict this
In the test I create a non indexed heap, insert some record and check the log, then repeat the test on an indexed heap.
The results suggest that even though the conditions for minimal logging into a indexed heap are met, minimal logging is not happening although it does happen on an non indexed heap. What am I doing wrong?
CREATE DATABASE logtest GO USE logtest GO CREATE TABLE test (field varchar(100)) GO CHECKPOINT
I am using three tables in this query, one is events_detail, one is events_summary, the third if gifts. The original select statement counted the number of ids (event_details.id_number) that appear per event_name (event_summary.event_name).
Now, I would like to add in another column that counts the number of IDs that gave a gift who attended an event that were also listed in the event_ details table. So far I have come up with the following. My main issue is linking the subquery properly back to the main query. how to count in the sub-query and have the result placed within the groups results in the main query.
SELECT es.event_name, es.event_id, COUNT(ed.id_number) Number_Attendees, ( SELECT COUNT(gifts.donor_id) AS Count2 FROM gifts WHERE gifts.donor_id = ed.id_number ) subquery2
Hello! I would like when I compare query plans to be able to compare 2 queries where the 1. is the "normal" version and the 2. the version where I forced compiler not to use a specific index (i don't want to force at table scan, so hint index(0) can't be used).
The only way I see how I could achieve something similar is to to drop the index and compare response time before and after. But building index could be time consuming...
Is it possible?
select col42 from tbl; select col42 from tbl with...
Hi All,I have a database that is serving a web site with reasonably hightraffiic.We're getting errors at certain points where processes are beinglocked. In particular, one of our people has suggested that an updatestatement contained within a stored procedure that uses a wherecondition that only touches on a column that has a clustered primaryindex on it will still cause a table lock.So, for example:UPDATE ORDERS SETprod = @product,val = @valWHERE ordid = @ordidIn this case ordid has a clustered primary index on it.Can anyone tell me if this would be the case, and if there's a way ofensuring that we are only doing a row lock on the record specified inthe where condition?Many, many thanks in advance!Much warmth,Murray
We are developing a project that is expected to hold TB of data and the back end used is SQL Server 2005.
I have the following problem
I have applied Nonclustered index over a column on a table.
Designed a SP for insertion which caters for updation incase the criteria based on the input is met.
The logic goes like this
Incase there exists a row containing the value of the column that is indexed for uniqueness, there should be updation. If not there should be a new row created.
However often there is an error message that is placed above. This happens only on some of the SPs and only on rare occasions.
Can any body tell me if there is any problem with the SQL Server 2005
