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  • Clustered index on frequently changing reference table of one or more foreign keys

    - by Ian
    My specific concern is related to the performance of a clustered index on a reference table that has many rapid inserts and deletes. Table 1 "Collection" collection_pk int (among other fields) Table 2 "Item" item_pk int (among other fields) Reference Table "Collection_Items" collection_pk int, item_pk int (combined primary key) Because the primary key is composed of both pks, a clustered index is created and the data physically ordered in the table according to the combined keys. I have many users creating and deleting collections and adding and removing items to those collections very frequently affecting the "Collection_Items" table, and its clustered index. QUESTION PART: Since the "Collection_Items" table is so dynamic, wouldn't there be a big performance hit on constantly resorting the table rows because of the clustered index ? If yes, what should I do to minimize this ?

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  • Getting #Error value from ssrs reporting

    - by deepa
    I have created a dataset with fields "LastRunBuild" and "project" .The LastRunBuild field contain string of data seperated by commas according to each project. But Some Projects have no value in LastRunBuild field.When i am using this expression " iif(Fields!LastRunBuild.Value=nothing, nothing,Split(Fields!LastRunBuild.Value,",").GetValue(3)) " a #Error value returns every time. Please reply...

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  • How to join by column name

    - by Daniel Vaca
    I have a table T1 such that gsdv |nsdv |esdv ------------------- 228.90 |216.41|0.00 and a table T2 such that ds |nm -------------------------- 'Non-Revenue Sales'|'ESDV' 'Gross Sales' |'GSDV' 'Net Sales' |'NSDV' How do I get the following table? ds |nm |val --------------------------------- 'Non-Revenue Sales'|'ESDV'|0.00 'Gross Sales' |'GSDV'|228.90 'Net Sales' |'NSDV'|216.41 I know that I can this by doing the following SELECT ds,nm,esdv val FROM T1,T2 WHERE nm = 'esdv' UNION SELECT ds,nm,gsdv val FROM T1,T2 WHERE nm = 'gsdv' UNION SELECT ds,nm,nsdv val FROM T1,T2 WHERE nm = 'nsdv' but I am looking for a more generic/nicer solution. I am using Sybase, but if you can think of a way to do this with other DBMS, please let me know. Thanks.

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  • MYSQL to UPDATE table if row with 2 specific columns exist or INSERT new row if it does not exist

    - by user2509541
    I have a MYSQL table that looks as follows: id id_jugador id_partido team1 team2 1 2 1 5 2 2 2 2 1 1 3 1 2 0 0 I need to create a query to either INSERT new rows in the table or UPDATE the table. The condition is based on id_jugador and id_partido, meaning that if I wanted to insert id_jugador = 2 and id_partido = 1, then it should just UPDATE the existing row with the new team1 and team2 values I am sending. And dont duplicate the row. However, if I have an entry id_jugador=2 and id_partido=3, since this combination does not exist yet, it should add the new row. I read about the REPLACE INTO but it seems to be unable to check combination of UNIQUE KEYS.

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  • Create a trigger on Oracle Databae that updates the field in a table when a field in onether table i

    - by GigaPr
    Hi, i have two tables Order(id, date, note) and Delivery(Id, Note, Date) I want to create a trigger that updates the date in delivery when the date is updated in Order I was thinking to do something like CREATE OR REPLACE TRIGGER your_trigger_name BEFORE UPDATE ON Order DECLARE BEGIN UPDATE Delivery set date = ??? where id = ??? END; How do i get the date and row id? thanks

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  • Foreach loop problem for Iqueyable object

    - by Vikas
    Hi, Can we use foreach loop for Iqueryable object? I'd like to do something as follow: query = Iqueryable<Myclass> = objDataContext.Myclass; // objDataContext is an object of LINQ datacontext class int[] arr1 = new int[] { 3, 4, 5 }; foreach (int i in arr1) { query = query.Where(q => (q.f_id1 == i || q.f_id2 == i || q.f_id3 == i)); } It gives me wrong output as each time value if i is changed.

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  • Alternatives to sign() in sqlite for custom order by

    - by Pentium10
    I have a string column which contains some numeric fields, but a lot are 0, empty string or null. The rest are numbers having different range, all positive. I tried to create a custom order by. The order would be done by two fields. First I would like to order the fields that have this number 0 and then sort by name. So something this would work: select * from table order by sign(referenceid) desc, name asc; But Sqlite lacks the sign() -1/0/1 function, and I am on Android and I can't create user defined functions. What other options I have to get this sort done.

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  • Simple aggregating query very slow in PostgreSql, any way to improve?

    - by Ash
    HI I have a table which holds files and their types such as CREATE TABLE files ( id SERIAL PRIMARY KEY, name VARCHAR(255), filetype VARCHAR(255), ... ); and another table for holding file properties such as CREATE TABLE properties ( id SERIAL PRIMARY KEY, file_id INTEGER CONSTRAINT fk_files REFERENCES files(id), size INTEGER, ... // other property fields ); The file_id field has an index. The file table has around 800k lines, and the properties table around 200k (not all files necessarily have/need a properties). I want to do aggregating queries, for example find the average size and standard deviation for all file types. But it's very slow - around 70 seconds for the latter query. I understand it needs a sequential scan, but still it seems too much. Here's the query SELECT f.filetype, avg(size), stddev(size) FROM files as f, properties as pr WHERE f.id = pr.file_id GROUP BY f.filetype; and the explain HashAggregate (cost=140292.20..140293.94 rows=116 width=13) (actual time=74013.621..74013.954 rows=110 loops=1) -> Hash Join (cost=6780.19..138945.47 rows=179564 width=13) (actual time=1520.104..73156.531 rows=179499 loops=1) Hash Cond: (f.id = pr.file_id) -> Seq Scan on files f (cost=0.00..108365.41 rows=1140941 width=9) (actual time=0.998..62569.628 rows=805270 loops=1) -> Hash (cost=3658.64..3658.64 rows=179564 width=12) (actual time=1131.053..1131.053 rows=179499 loops=1) -> Seq Scan on properties pr (cost=0.00..3658.64 rows=179564 width=12) (actual time=0.753..557.171 rows=179574 loops=1) Total runtime: 74014.520 ms Any ideas why it is so slow/how to make it faster?

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  • create temporary table from cursor

    - by Claudiu
    Is there any way, in PostgreSQL accessed from Python using SQLObject, to create a temporary table from the results of a cursor? Previously, I had a query, and I created the temporary table directly from the query. I then had many other queries interacting w/ that temporary table. Now I have much more data, so I want to only process 1000 rows at a time or so. However, I can't do CREATE TEMP TABLE ... AS ... from a cursor, not as far as I can see. Is the only thing to do something like: rows = cur.fetchmany(1000); cur2 = conn.cursor() cur2.execute("""CREATE TEMP TABLE foobar (id INTEGER)""") for row in rows: cur2.execute("""INSERT INTO foobar (%d)""" % row) or is there a better way? This seems awfully inefficient.

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  • Does UNIQ constraint mean also an index on that field(s)?

    - by Gremo
    As title, should i defined a separate index on email column (for searching purposes) or the index is "automatically" added along with UNIQ_EMAIL_USER constraint? CREATE TABLE IF NOT EXISTS `customer` ( `id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(11) NOT NULL, `first` varchar(255) NOT NULL, `last` varchar(255) NOT NULL, `slug` varchar(255) NOT NULL, `email` varchar(255) NOT NULL, `created_at` datetime NOT NULL, `updated_at` datetime NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `UNIQ_SLUG` (`slug`), UNIQUE KEY `UNIQ_EMAIL_USER` (`email`,`user_id`), KEY `IDX_USER` (`user_id`) ) ENGINE=InnoDB;

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  • JSON - Php/SQL iPhone APP Questions/Help

    - by chance
    Hey group, first time posting here I am somewhat new to the JSON/PHP/mySQL world, but been around iPhone designing for the past few years, though this topic of conversation is a while new area I am entering. I have done JSON iPhone examples that allow me to create a UITableView and display the JSON data into the TableViewCells (CustomCells) and displays the data (NSDictionary)into UILabels The problem I am having now, is that I want an APP that displays this information from the JSON into just a couple of UILabel's on a regular UIViewController and not a UITableView any help would greatly be appreciated, the example I used and learned for JSON and UITABLE was from http://tempered.mobi/%20 I used that example from my app, but incorporated a few other things like CUSTOM cells however now when the USER selects the specific CELL I want it to load specific data from another JSON file, and cannot get it to load in a UILabel or UITextView in a UIViewController HELP :-)

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  • The best practice to setup hierarchy data

    - by eski
    I'm trying to figure out the best practice to setup hierarchy data that i take from a database into some contoller that would show the hierachy. Basicly this would look like a normal tree but when you press the items that are under "chapters" you get a link to another page. I have these tables and this is the way they are connected Period Courses Subjects Chapters I select Period from a DropDownBox and then i want all the courses in that period to line up. Under each course would be the subject and under them are the chapers, typical hierarchy. The tables are linked together with refrences to each other in linear way. I have tried to use treeview to show this, but dont understand how to do it. I though i could use <ul><il> tags and do it at runtime. Reapeter or datalist, possible ? Is it better to do this with databinding in XAML or in code ?

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  • AJAX in ASP.NET - How do I check a checkbox and have the action reflected in the database?

    - by hamlin11
    This is about as beginner as it gets regarding AJAX, but here it goes. I want to have one checkbox somewhere on an ASP.NET web form (ASPX). When the user clicks the checkbox, I want one of those spinning indicators to show. While that spinning indicator is showing, I want an update operation to occur in the database to reflect that the user has intended for that checkbox to be checked. update MyTable set CheckboxChecked = 1 Then, as soon as the update operation has occurred, I want that to be reflected in the checkbox by removing the spinning indicator and replacing it with the standard checked checkbox. I'm guessing this is done with an UpdatePanel and possibly an update statement followed by a looped call to a select statement... but I have never used AJAX before and have no idea how to go about it. Thanks!

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  • How do I all the registered users on a day report

    - by Nadal
    I have a table called users where I have two columns: name and created_at. created_at column column is of type datetime and it stores the datetime when this user was created. I need to know the number of users created for a given date range. Let's say I ask give me user report between 1-nov-2010 and 30-nov-2010 . I need something like this 1-nov-2010: 2 2-nov-2010: 5 The problem I am running into is that created_at data has value upto second. How do I check if a created_at date falls within a given date. Any help in solving this problem is appreciated. I am using mysql5.

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  • SSRS Performance Mystery

    - by user101654
    I have a stored procedure that returns about 50000 records in 10sec using at most 2 cores in SSMS. The SSRS report using the stored procedure was taking 20min and would max out the processor on an 8 core server for the entire time. The report was relatively simple (i.e. no graphs, calculations). The report did not appear to be the issue as I wrote the 50K rows to a temp table and the report could display the data in a few seconds. I tried many different ideas for testing altering the stored procedure each time, but keeping the original code in a separate window to revert back to. After one Alter of the stored procedure, going back to the original code, the report and server utilization started running fast, comparable to the performance of the stored procedure alone. Everything is fine for now, but I am would like to get to the bottom of what caused this in case it happens again. Any ideas?

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  • Date range advanced count calculation in TSQL

    - by cihata87
    I am working on call center project and I have to calculate the call arrivals at the same time between specific time ranges. I have to write a procedure which has parameters StartTime, EndTime and Interval For Example: Start Time: 11:00 End Time: 12:00 Interval: 20 minutes so program should divide the 1-hour time range into 3 parts and each part should count the arrivals which started and finished in this range OR arrivals which started and haven't finished yet Should be like this: 11:00 - 11:20 15 calls at the same time(TimePeaks) 11:20 - 11:40 21 calls ... 11:40 - 12:00 8 calls ... Any suggestions how to calculate them?

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  • How to use value from primary accessdatasource control as parameter in select query for secondary ac

    - by weedave
    Hi, I'm trying to display all orders placed and I have a primary accessdatasource control that has a select query to get the customer information and the orderID. I want to use the orderID value from this first query as a parameter for the secondary accessdatasource control that selects the product information of the products in the order. In plain english, I want to:- select product info from product table where orderID = ? (where ? is the orderID value from the first query) I have tried the <%#Eval("OrderID")% but I get a "server tag not well formed" error, but I do get results returned when I just type the order ID in, but obviously every result (order) just contains the same product info... <asp:Repeater ID="Repeater1" runat="server" DataSourceID="AccessDataSource1"> <ItemTemplate> <asp:AccessDataSource ID="AccessDataSource2" runat="server" DataFile="~/App_Data/project.mdb" SelectCommand="SELECT orderDetails.OrderID, album.Artist, album.Album, album.Cost, album.ImageURL, orderDetails.Quantity, orderDetails.Total FROM (album INNER JOIN orderDetails ON album.AlbumID = orderDetails.AlbumID) WHERE (orderDetails.OrderID = ? )"> <SelectParameters> // Error is on this line <asp:Parameter Name="OrderID" DefaultValue="<%#Eval ("OrderID")%>" /> </SelectParameters> </asp:AccessDataSource> <div class="viewAllOrdersOrderArea"> <div class="viewAllOrdersOrderSummary"> <p><b>Order ID: </b><%#Eval("OrderID")%></p> <h4>Shipping Details</h4> <p><b>Shipping Address: </b><%#Eval("ShippingName")%>, <%#Eval("ShippingAddress")%>, <%#Eval("ShippingTown")%>, <%#Eval("ShippingPostcode")%></p> <h4>Payment Details</h4> <p><b>Cardholder's Address: </b><%#Eval("CardHolder")%>, <%#Eval("BillingAddress")%>, <%#Eval("BillingTown")%>, <%#Eval("BillingPostcode")%></p> <p><b>Payment Method: </b><%#Eval("CardType")%></p> <p><b>Card Number: </b><%#Eval("CardNumber")%></p> <p><b>Start Date: </b><%#Eval("StartDate")%>, Expiry Date: <%#Eval("ExpiryDate")%></p> <p><b>Security Digits: </b><%#Eval("SecurityDigits")%></p> <h4>Ordered items:</h4> <asp:Repeater ID="Repeater2" runat="server" DataSourceID="AccessDataSource2"> <ItemTemplate> <div style="display: block; float: left;"> <div class="viewAllOrdersProductImage"> <img width="70px" height="70px" alt="<%# Eval("Artist") %> - <%# Eval("Album") %>" src="assets/images/thumbs/<%# Eval("ImageURL") %>" /> </div> <div style="display:block; float:left; padding-top:15px; padding-right:20px;"><p><b><%# Eval("Artist") %> - <%# Eval("Album") %></b></p> <p>£<%# Eval("Cost") %> x <%# Eval("Quantity") %> = £<%#Eval("Total")%></p></div> </div> </ItemTemplate> </asp:Repeater> </div> </div> </ItemTemplate> </asp:Repeater>

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  • SELECT table name that is inside UNION

    - by LexRema
    I have two same tables. I need to union them in such way: SELECT f1,f2, xxx FROM (SELECT * FROM tbl1 UNION ALL SELECT * FROM tbl2) where xxx would query for a table name, where f1 and f2 fields are taken from. Example output: 123 345 'tbl1' -- this rows are from the first table 121 345 'tbl1' 121 345 'tbl1' 123 345 'tbl1' 124 345 'tbl1' 125 345 'tbl2' -- this rows are from the second table 127 345 'tbl2' Thank you in advance.

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  • How to output multiple rows from an SQL query using the mysqli object

    - by Jonathan
    Assuming that the mysqli object is already instantiatied (and connected) with the global variable $mysql, here is the code I am trying to work with. class Listing { private $mysql; function getListingInfo($l_id = "", $category = "", $subcategory = "", $username = "", $status = "active") { $condition = "`status` = '$status'"; if (!empty($l_id)) $condition .= "AND `L_ID` = '$l_id'"; if (!empty($category)) $condition .= "AND `category` = '$category'"; if (!empty($subcategory)) $condition .= "AND `subcategory` = '$subcategory'"; if (!empty($username)) $condition .= "AND `username` = '$username'"; $result = $this->mysql->query("SELECT * FROM listing WHERE $condition") or die('Error fetching values'); $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; return $info; } } there are several hundred listings in the db and when I call $result-fetch_array() it places in an array the first row in the db. however when I try to call the object, I can't seem to access more than the first row. for instance: $listing_row = new Listing; while ($listing = $listing_row-getListingInfo()) { echo $listing[0]; } this outputs an infinite loop of the same row in the db. Why does it not advance to the next row? if I move the code: $this->listing = $result->fetch_array() or die('could not create object'); foreach ($this->listing as $key => $value) : $info[$key] = stripslashes(html_entity_decode($value)); endforeach; if I move this outside the class, it works exactly as expected outputting a row at a time while looping through the while statement. Is there a way to write this so that I can keep the fetch_array() call in the class and still loop through the records?

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  • my output parameters are always null when i use BeginExecuteNonQuery

    - by CharlesO
    I have a stored procedure that returns a varchar(160) as an output parameter of a stored procedure. Everything works fine when i use ExecuteNonQuery, i always get back the expected value. However, once i switch to use BeginExecuteNonQuery, i get a null value for the output. I am using connString + "Asynchronous Processing=true;" in both cases. Sadly the BeginExecuteNonQuery is about 1.5 times faster in my case...but i really need the output parameter. Thanks!

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  • Oracle Sql: how to substract rows from one table from another only once

    - by slyder07
    I'm working for a university project, and I have the following question: I have 2 tables in a Oracle DB... I need to select those rows from table1, which are not included in table2... But the main problem is that I need to exclude that rows from table2 wich was selected once... For example: Table1 Table2 ResultTable id | Number | Letter id | Number | Letter id | Number | Letter _____________________ _____________________ _____________________ 1 4 S 1 6 G 2 2 P 2 2 P 2 8 B 3 5 B 3 5 B 3 4 S 4 4 S 4 4 S 4 1 A 6 2 P 5 1 A 5 1 H 6 2 P 6 2 X So, how you see it, if one row from Table1 has a "twin" in Table2, they both are excluded. Hope I was explicit enough. Sorry for my bad English. Thanks.

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