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  • Problem with MySQL query

    - by Psyche
    This time my setup looks like this: one table with galleries names (gallery_id, gallery_name) and another table with galleries photos (photo_id, photo_gallery_id, photo_name). What I need is to get all the galleries with one random picture for each gallery. Is it possible to do this with a single query?

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  • Most efficient way to Update with Linq2Sql

    - by pranay
    can I update my employee record as given in below function or i have to make query of employee collection first and than i update data public int updateEmployee(App3_EMPLOYEE employee) { DBContextDataContext db = new DBContextDataContext(); db.App3_EMPLOYEEs.Attach(employee); db.SubmitChanges(); return employee.PKEY; } or i have to do this public int updateEmployee(App3_EMPLOYEE employee) { DBContextDataContext db = new DBContextDataContext(); App3_EMPLOYEE emp = db.App3_EMPLOYEEs.Single(e => e.PKEY == employee.PKEY); db.App3_EMPLOYEEs.Attach(employee,emp); db.SubmitChanges(); return employee.PKEY; } But i dont want to use second option is there any efficient way to update data

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  • Is an index required for columns in ON clause?

    - by newbie
    Do I have to create an index on columns referenced in Joins? E.g. SELECT * FROM left_table INNER JOIN right_table ON left_table.foo = right_table.bar WHERE ... Should I create indexes on left_table(foo), right_table(bar), or both? I noticed different results when I used EXPLAIN (Postgresql) with and without indexes and switching around the order of the comparison (right_table.bar = left_table.foo) I know for sure that indexes are used for the left of the WHERE clause but I am wondering whether I need indexes for columns listed in ON clauses.

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  • Best way to get distinct values from large table

    - by derivation
    I have a db table with about 10 or so columns, two of which are month and year. The table has about 250k rows now, and we expect it to grow by about 100-150k records a month. A lot of queries involve the month and year column (ex, all records from march 2010), and so we frequently need to get the available month and year combinations (ie do we have records for april 2010?). A coworker thinks that we should have a separate table from our main one that only contains the months and years we have data for. We only add records to our main table once a month, so it would just be a small update on the end of our scripts to add the new entry to this second table. This second table would be queried whenever we need to find the available month/year entries on the first table. This solution feels kludgy to me and a violation of DRY. What do you think is the correct way of solving this problem? Is there a better way than having two tables?

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  • Firebird 2.1 + EXISTS = query bug?

    - by Atlas
    Using Delphi 2009 + Firebird 2.1.3. Database is ODS 11.1, default char set is UTF8. My prepared query is as follows: SELECT a.po_id, a.po_no FROM purchase_order a WHERE EXISTS (SELECT 1 FROM sales_order_item z1 JOIN purchase_order_item z2 ON z2.so_item_id = z1.so_item_id AND z2.po_id = a.po_id WHERE z1.so_id = :soid) ORDER BY a.po_no Now when I loop this say 1000 times because I have 1000 x so_id, the CPU usage get at 100% for FBSERVER.EXE Anyone encountered this problem?

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  • is NATURAL JOIN any better than SELECT FROM WHERE in terms of performance ?

    - by ashy_32bit
    Today I got into a debate with my project manager about Cartesian products. He says a 'natural join' is somehow much better than using 'select from where' because the later cause the db engine to internally perform a Cartesian product but the former uses another approach that prevents this. As far as I know, the natural join syntax is not any different in anyway than 'select from where' in terms of performance or meaning, I mean you can use either based on your taste. SELECT * FROM table1,table2 WHERE table1.id=table2.id SELECT * FROM table1 NATURAL JOIN table2 please elaborate about the first query causing a Cartesian product but the second one being somehow more smart

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  • Query to check the consistency of records

    - by orunner
    I have four tables TableA: id1 id2 id3 value TableB: id1 desc TableC: id2 desc TableD: id3 desc What I need to do is to check if all combinations of id1 id2 id3 from table B C and D exist in the TableA. In other words, table A should contain all possible combinations of id1 id2 and id3 which are stored in the other three tables.

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  • PHP Try and Catch for SQL Insert

    - by meme
    I have a page on my website (high traffic) that does an insert on every page load. I am curious of the fastest and safest way to (catch an error) and continue if the system is not able to do the insert into MySQL. Should I use try/catch or die or something else. I want to make sure the insert happens but if for some reason it can't I want the page to continue to load anyway. ... $db = mysql_select_db('mobile', $conn); mysql_query("INSERT INTO redirects SET ua_string = '$ua_string'") or die('Error #10'); mysql_close($conn); ...

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  • Oracle query with LOWER

    - by Nickolodeon
    Hi. Why this returns 0 rows SELECT GARTUSERID, USER_CODE, UNITID, RANKCODE, RANKID, FIO, LOGINNAME, START_DATE, EXPIR_DATE, NOTE, POSITION, ISCHGPASSWORD, IS_EXPIRDATE, IS_BLOCKED, ROW_ID FROM ACONTROL.GARTUSERS WHERE LOWER(LOGINNAME)=LOWER(:LOGIN) AND ROW_ID=:MD5PSWD and this returns 1 row (as I wanted for the first query)? SELECT GARTUSERID, USER_CODE, UNITID, RANKCODE, RANKID, FIO, LOGINNAME, START_DATE, EXPIR_DATE, NOTE, POSITION, ISCHGPASSWORD, IS_EXPIRDATE, IS_BLOCKED, ROW_ID FROM ACONTROL.GARTUSERS WHERE LOGINNAME=:LOGIN AND ROW_ID=:MD5PSWD

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  • Help with sql query

    - by user225269
    I have two tables: subject and student. I'm trying to count the number of subjects enrolled by each student. How do I do that?I'm trying the code below but it doesn't give the answer I need. Please help. SELECT COUNT( subject.SUBJECT ) , student.IDNO, student.FIRSTNAME, subject.SUBJECT FROM student, subject GROUP BY subject.SUBJECT LIMIT 0 , 30

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  • Counting the instances of customers

    - by Mikae Combarado
    Say that I have a table with one column named CustomerId. The example of the instance of this table is : CustomerId 14 12 11 204 14 204 I want to write a query that counts the number of occurences of customer IDs. At the end, I would like to have a result like this : CustomerId NumberOfOccurences 14 2 12 1 11 1 204 2 14 1 I cannot think of a way to do this.

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  • Find Consecutive Rows & Calculate Duration

    - by MannyKo
    I have a set a of data that tells me if a couple of systems are available or not every 5 or 15 minutes increments. For now, the time increment shouldn't matter. The data looks like this: Status Time System_ID T 10:00 S01 T 10:15 S01 F 10:30 S01 F 10:45 S01 F 11:00 S01 T 11:15 S01 T 11:30 S01 F 11:45 S01 F 12:00 S01 F 12:15 S01 T 12:30 S01 F 10:00 S02 F 10:15 S02 F 10:30 S02 F 10:45 S02 F 11:00 S02 T 11:15 S02 T 11:30 S02 I want to create a view that tells when a system is NOT available (i.e. when it is F), from what time, to what time, and duration which is to - from. Desired results: System_ID From To Duration S01 10:30 11:00 00:30 S01 11:45 12:15 00:30 S02 10:00 11:00 01:00 Here is the script data: DROP SCHEMA IF EXISTS Sys_data CASCADE; CREATE SCHEMA Sys_data; CREATE TABLE test_data ( status BOOLEAN, dTime TIME, sys_ID VARCHAR(10), PRIMARY KEY (dTime, sys_ID) ); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '10:00:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '10:15:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:30:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:45:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '11:00:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '11:15:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '11:30:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '11:45:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '12:00:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '12:15:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '12:30:00', 'S01'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:00:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:15:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:30:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '10:45:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (FALSE, '11:00:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '11:15:00', 'S02'); INSERT INTO test_data (status, dTime, sys_ID) VALUES (TRUE, '11:30:00', 'S02'); Thank you in advance!

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  • mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in

    - by user2533440
    I cannot figure out whats wrong with this code. Every time i try to run this file I get error mysql_fetch_assoc() expects parameter 1 to be resource <?php $q = "select * from tbfood"; $rs = mysql_query($q); while($msg = mysql_fetch_assoc($rs)){ echo "<p>".$msg["name"]."</p>"; echo "<p>".$msg["price"]."</p>"; if ($msg['idDruh'] == 1) { echo "string1"; } elseif ($msg['idDruh'] == 2) { echo "string2"; } elseif ($msg['idDruh'] == 3) { echo "string3"; } elseif ($msg['idDruh'] == 4) { echo "string4"; } elseif ($msg['idDruh'] == 5) { echo "string5"; } elseif ($msg['idDruh'] == 6) { echo "string6"; } elseif ($msg['idDruh'] == 7) { echo "string7"; } } ?>

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  • distinction between using .text and .value in VBA access

    - by every_answer_gets_a_point
    i am passing the textbox1.text values into a query and sometimes into a string sometimes i say this: dim combor1 as string combor1 = comboReason1.Text how do i know when i should put combor1=comboreason1.value ?? also why do i need to set focus for a control to reference its property? that doesn't make sense to me also when i set combor4 = comboReason4.Value and the .value is null, then i get an error about invalid use of null please help!

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  • MySQL: group by and IF statement

    - by notset
    By default, parent_id = 0. I want to select all records with parent_id = 0 and only the last ones with parent_id 0. I tried this, but it didn't work: SELECT * FROM `articles` IF `parent_id` > 0 THEN GROUP BY `parent_id` HAVING COUNT(`parent_id`) >= 1 END; ORDER BY `time` DESC What could be the solution?

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  • oracle query returns 4 duplicates of each row

    - by ajoe
    hello, I am Running a oracle query, it seems to work except that it returns 4 dupes of each result. here is the code: Select * from (Select a.*, rownum rnum From (SELECT NEW_USER.*, NEW_EHS_QUIZ_COMPLETE.datetime FROM NEW_USER, NEW_EHS_QUIZ_COMPLETE WHERE EXISTS(select * from NEW_EHS_QUIZ_COMPLETE where NEW_USER.id=NEW_EHS_QUIZ_COMPLETE.USER_ID) ORDER by last_name ASC ) a where rownum <= #pgtop# ) where rnum >= #pgbot# does anyone know why this isnt working properly? thanks in advance.

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  • Limiting Subscriptions to be emailed using SSRS

    - by Graeme
    Currently, our system will do a "foreach" over all Subscriptions which are returned from the ListSubscriptions method of ReportingService and fire a Timed Subscription event so that they receive the report as an email. In our dev environment, I don't want every subscription of these reports to be sent out when we are testing. Is there a way I can create a new subscription with my own email address being used so that I receive the report? The temp subscription could then be deleted after sending. Any ideas on how to do this?

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  • Help doing a dynamic sort?

    - by Kevin
    I have a notifications table which contains different types of notifications for different events. Inside the table is a notifications_type:string column that contains the type of notification, i.e. "foo" or "bar" or "oof" I want the user to be able to select what notifications they want to display, so there are checkboxes below the result that correspond to prefs_display_foo:boolean, prefs_display_bar:boolean in the User model. What is an elegant way for me to set the :conditions in the find to properly display the sorted results? Also, currently I have it as a method in the user, but how would I do it as a has_many :notifications, :conditions = .....

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  • dbo in SqlServer

    - by ala
    I'm converting database from Teradata to SqlServer. I've noticed all tables and procedures are named by the prefix "dbo." (e.g. "dbo.Table1"). I would like to know if and how I can get rid of "dbo" because it would make the conversion task a lot more easier.

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  • php mysql_fetch_array() error

    - by user1877823
    I am getting this error while i am trying to delete a record the query is working but this line remains on the page. i want to echo "Deleted" written in the while should show up but the while loop is not working, i have tried and searched alot nothing helps! mysql_fetch_array() expects parameter 1 to be resource, boolean given in delete.php on line 27 delete.php <html> <body> <form method="post"> Id : <input type="text" name="id"> Name : <input type="text" name="name"> Description : <input type="text" name="des"> <input type="submit" value="delete" name="delete"> </form> <?php include("connect.php"); $id = $_POST['id']; $name = $_POST['name']; $des = $_POST['des']; $result = mysql_query("DELETE FROM fact WHERE id='$id'") or die(mysql_error()); while($row = mysql_fetch_array($result)) { echo "Deleted"; } mysql_close($con); ?> </body> </html> connect.php <?php $con = mysql_connect("localhost","root",""); if (!$con) { die('Could not connect: ' . mysql_error()); } mysql_select_db("Dataentry", $con); ?> How should i make the while loop work..

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