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  • MySQL customized join query using multiple tables

    - by itgeek
    I am searching one student from each class from one group. There are different class groups and every group has different classes and every class has multiple students. See below: Group1 --> Class1, Class2 etc Class1 --> GreenStudent1, GreenStudent2 etc Class2 --> RedStudent1, RedStudent2 etc ------------------------------------------------------ SELECT table1.id, table1.myname, table1.marks table2.studentid, table2.studentname FROM table1 INNER JOIN table3 ON table1.oldid = table3.id INNER JOIN table2 ON table2.studentid = table3.newid WHERE table1.classgroup = 'SCI79' GROUP BY table1.oldid ORDER BY table1.marks DESC There are different joins applied in the query. Above mentioned query giving me correct results but I need little modification in it. Current query returning me one student from each class. What I need? I need one student from each class but only that student who has MAXIMUM table1.marks So I should have one student from each class who has maximum number in their relevant classes. Can anyone suggest some solution or rewrite this query? Thanks :)

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  • MySql product\tag query optimisation - please help!

    - by Nige
    Hi There I have an sql query i am struggling to optimise. It basically is used to pull back products for a shopping cart. The products each have tags attached using a many to many table product_tag and also i pull back a store name from a separate store table. Im using group_concat to get a list of tags for the display (this is why i have the strange groupby orderby clauses at the bottom) and i need to order by dateadded, showing the latest scheduled product first. Here is the query.... SELECT products.*, stores.name, GROUP_CONCAT(tags.taglabel ORDER BY tags.id ASC SEPARATOR " ") taglist FROM (products) JOIN product_tag ON products.id=product_tag.productid JOIN tags ON tags.id=product_tag.tagid JOIN stores ON products.cid=stores.siteid WHERE dateadded < '2010-05-28 07:55:41' GROUP BY products.id ASC ORDER BY products.dateadded DESC LIMIT 2 Unfortunately even with a small set of data (3 tags and about 12 products) the query is taking 00.0034 seconds to run. Eventually i want to have about 2000 products and 50 tagsin this system (im guessing this will be very slooooow). Here is the ExplainSql... id|select_type|table|type|possible_keys|key|key_len|ref|rows|Extra 1|SIMPLE|tags|ALL|PRIMARY|NULL|NULL|NULL|4|Using temporary; Using filesort 1|SIMPLE|product_tag|ref|tagid,productid|tagid|4|cs_final.tags.id|2| 1|SIMPLE|products|eq_ref|PRIMARY,cid|PRIMARY|4|cs_final.product_tag.productid|1|Using where 1|SIMPLE|stores|ALL|siteid|NULL|NULL|NULL|7|Using where; Using join buffer Can anyone help?

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  • MySql returning multiple rows from stored procedure / function

    - by pistacchio
    Hi, I need to make a stored procedure or function that returns a set of rows. I've noted that in a stored procedure i can SELECT * FROM table with success. If i fetch rows in a loop and SELECT something, something_other FROM table once per loop execution, I only get one single result. What I need to do is looping, doing some calculations and returning a rowset. What's the best way to do this? A temporary table? Stored functions? Any help appreciated.

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  • Optimize SELECT DISTINCT CONCAT query in MySQL

    - by L. Cosio
    Hello! I'm running this query: SELECT DISTINCT CONCAT(ALFA_CLAVE, FECHA_NACI) FROM listado GROUP BY ALFA_CLAVE HAVING count(CONCAT(ALFA_CLAVE, FECHA_NACI)) > 1 Is there any way to optimize it? Queries are taking 2-3 hours on a table with 850,000 rows. Adding an index to ALFA_CLAVE and FECHA_NACI would work? Thanks in advanced

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  • MySQL count statements error - operand should contain 1 column(s)

    - by jason
    I am trying to do multiple counts everyone was working accept the first sub select (list1) I get an error that reads "Operand should contain 1 column(s)" i'm guessing it has something to do with the AND, but i'm not sure how I would fix this one. Select Count(list0.ustatus) AS finished_count, (Select list1.ustatus, Count(*) From listofupdates list1 Where list1.ustarted != '0000-00-00 00:00:00' AND list1.ustatus != 1) AS start_count, (Select Count(list2.udifficulty) From listofupdates list2 Where list2.udifficulty = 2) AS recheck_count, (Select Count(list3.udifficulty) From listofupdates list3 Where list3.udifficulty = 4) AS question_count From listofupdates list0 Where list0.ustatus = 1

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  • PHP & MySQL Pagination Update Help

    - by TaG
    Its been a while since I updated my pagination on my web page and I'm trying to add First and Last Links to my pagination as well as the ... when the search results are to long. For example I'm trying to achieve the following in the example below. Can some one help me fix my code so I can update my site. Thanks Previous First 1 2 3 4 5 6 7 ... 199 200 Last Next I currently have the following displayed using my code. Previous 1 2 3 4 5 6 7 Next Here is the part of my pagination code that displays the links. if ($pages > 1) { echo '<br /><p>'; $current_page = ($start/$display) + 1; if ($current_page != 1) { echo '<a href="index.php?s=' . ($start - $display) . '&p=' . $pages . '">Previous</a> '; } for ($i = 1; $i <= $pages; $i++) { if ($i != $current_page) { echo '<a href="index.php?s=' . (($display * ($i - 1))) . '&p=' . $pages . '">' . $i . '</a> '; } else { echo '<span>' . $i . '</span> '; } } if ($current_page != $pages) { echo '<a href="index.php?s=' . ($start + $display) . '&p=' . $pages . '">Next</a>'; } echo '</p>'; }

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  • How to get this done in mysql?

    - by bala3569
    Consider i have a registartion table and there is field prefLocationId and it contains value like this 1,2,3,2,1,4 and so many.... And i have a table prefLocation which looks like this Id LocationName 1 Chennai 2 Mumbai 3 Kolkatta 4 Delhi and i want to select record of users and show values like Chennai,Mumbai,Kolkatta,Mumbai,Chennai,Delhi and so on...

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  • mysql query to concat information from 3 tables - getting incorrect result count

    - by iPfaffy
    I have 3 tables in my database. ab_contacts id first_name last_name addressbook_id ab_addressbooks name id co_comments id link_id comment I'd like to create a query that will let me select all the contacts and comments related to them in a given addressbook. To select all the people in a given addressbook, I can use: select count(*) from ab_contacts where addressbook_id = '50'; This returns 8152 people. However, when I run my query: select ab_contacts.first_name, ab_contacts.last_name, ab_contacts.email, ab_addressbooks.name, co_comments.comments from ab_contacts JOIN ab_addressbooks ON (ab_contacts.addressbook_id = ab_addressbooks.id) JOIN co_comments ON (ab_contacts.id = co_comments.link_id) WHERE ab_contacts.addressbook_id = '50';` the format works, but I only get 1045 results. I'm sure there is something I am missing, but I cannot figure it out. Any help would be greatly appreciated.

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  • How to change data structure in mysql using mysqldump without deleting files

    - by Don Quixote
    Essentially what I'm trying to do is sync a production server with a sandbox server, but only the table structures and stored procedures. The procedures aren't any problem since they can be overriden, but the problem is the tables. I want to sync and alter their structures on the production server using mysqldump (or any other way that you can propose) without altering any existing data. If it helps, I only want to add more columns, not remove any existing ones. Also, I am using mysqlyog. Is there any way to do this?

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  • Question about Benchmark function in Mysql ( Incredible results ).

    - by xRobot
    I have 2 tables: author with 3 millions of rows. book with 20 miles rows. . So I have benchmarked this query with a join: SELECT BENCHMARK(100000000, 'SELECT book.title, author.name FROM `book` , `author` WHERE book.id = author.book_id ') And this is the result: Query took 0.7438 sec ONLY 0.7438 seconds for 100 millions of query with a join ??? Do I make some mistakes or this is the right result ?

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  • select similar value from MySQL and order the result

    - by mathew
    how do I order this result?? $range = 5; // you'll be selecting around this range. $min = $rank - $range; $max = $rank + $range; $limit = 10; // max number of results you want. $result = mysql_query("select * from table where rank between $min and $max limit $limit"); while($row = mysql_fetch_array($result)) { echo $row['name']."&nbsp;-&nbsp;".$row['rank']."<br>"; }

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  • type casting in mysql

    - by muralikalpana
    i have passportno(varchar) in database. i am entering values like this 001,002,003. and i want to display like sorting order. now i wrote query like this "select * from passport_registration where status=1 ORDER BY passportno" then displaying output like this......077,088,099,100,1000,1001,1009,101,1010 i want to diplay sort order. how to do?

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  • Selecting data from mysql table and related data from another to join them

    - by knittledan
    Ive looked at other questions and answers but still dont understand which brings me here. I have one data base two tables. lets say table1 and table2 from database. I'm looking to grab all the information from table1 and only one column from table2 that coincides with the correct row in table1. Example which I know is wrong: SELECT table1.*, table2.time_stamp FROM table1, table2 WHERE table1.ticket_id=$var AND table1.user_id = table2.user_id Basically select data from table1 then use a value from the selected table to grab the related data from table2 and join them to output them as one mysql_query. Im sure its simple and has been asked before. edit: I dont receive an error. SQL just returns noting. log form of this would be: $sqlResults = mysql_query("SELECT table1.* FROM table1 WHERE table1.ticket_id=$var") while($rowResult = mysql_fetch_array( $sqlResults )) { $userID = $rowResult['user_id']; $sqlResults2 = mysql_query("SELECT table2.time_stamp FROM table2 WHERE table2.user_id=$userID") } I want to combine that into one sql statement so i dont have to hit table2 for every row table1 has

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  • mysql table creation problem..

    - by pradeep
    Hi, I have a small problem. I am creating an appointment table where in the foreign key is patient id which is referenced from patient table.This table is for all registered patients. there will be unregistered patients also, who will be seeking appointments.SO i just need to store the name,phone and few details. I don't want to make these 2 as different tables. So is there a way to skip the integrity check of foreign key when i ma inserting unregistered patient data

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  • MySQL: optimization of table (indexing, foreign key) with no primary keys

    - by Haradzieniec
    Each member has 0 or more orders. Each order contains at least 1 item. memberid - varchar, not integer - that's OK (please do not mention that's not very good, I can't change it). So, thera 3 tables: members, orders and order_items. Orders and order_items are below: CREATE TABLE `orders` ( `orderid` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT, `memberid` VARCHAR( 20 ), `Time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP , `info` VARCHAR( 3200 ) NULL , PRIMARY KEY (orderid) , FOREIGN KEY (memberid) REFERENCES members(memberid) ) ENGINE = InnoDB; CREATE TABLE `order_items` ( `orderid` INT(11) UNSIGNED NOT NULL, `item_number_in_cart` tinyint(1) NOT NULL , --- 5 items in cart= 5 rows `price` DECIMAL (6,2) NOT NULL, FOREIGN KEY (orderid) REFERENCES orders(orderid) ) ENGINE = InnoDB; So, order_items table looks like: orderid - item_number_in_cart - price: ... 1000456 - 1 - 24.99 1000456 - 2 - 39.99 1000456 - 3 - 4.99 1000456 - 4 - 17.97 1000457 - 1 - 20.00 1000458 - 1 - 99.99 1000459 - 1 - 2.99 1000459 - 2 - 69.99 1000460 - 1 - 4.99 ... As you see, order_items table has no primary keys (and I think there is no sense to create an auto_increment id for this table, because once we want to extract data, we always extract it as WHERE orderid='1000456' order by item_number_in_card asc - the whole block, id woudn't be helpful in queries). Once data is inserted into order_items, it's not UPDATEd, just SELECTed. The questions are: I think it's a good idea to put index on item_number_in_cart. Could anybody please confirm that? Is there anything else I have to do with order_items to increase the performance, or that looks pretty good? I could miss something because I'm a newbie. Thank you in advance.

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  • MySQL Query, Date Range From "Blacklist"

    - by erbaker
    I have 2 databases. One is properties and the other is dates. In dates I have associated the land_id and a date (In YYYYMMDD format) which means that the date is not available. I need to formulate a query that a user can specify a start and end date, and then choose a property for which dates are available (not in the date database). How do airline and hotel websites do this kind of logic? I was thinking about taking the date range and picking all days in between and doing a query where the dates do not match and ordering it by number of results, but I can see how that could easily turn into an intense query. CREATE TABLE IF NOT EXISTS `dates` ( `id` int(11) NOT NULL AUTO_INCREMENT, `land_id` int(11) NOT NULL, `date` varchar(255) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=44 ; -- -- Dumping data for table `dates` -- INSERT INTO `dates` (`id`, `land_id`, `date`) VALUES (43, 1, '20100526'), (39, 1, '20100522'), (40, 1, '20100523'), (41, 1, '20100521'), (42, 1, '20100525');

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  • MySQL look for missing ratings

    - by Dustin
    Hopefully I can ask this without being confusing. I am a photographer and I am having some of our clients rate pictures that we have taken. We have hundreds of pictures in our portfolio that they may be rating. What I want to do is ask our clients to rate pictures again, but only show them the pictures they haven't yet rated. I currently have three tables: one that stores the actual ratings, one that stores the pictures (or location of each picture), and one that stores the information about the rater. I'm using codeigniter for my db management, if that helps at all. What I have so far is this: "SELECT * FROM ratings LEFT JOIN portfolio ON ratings.portfolioid = portfolio.portfolioid" This will give me a row for each rating, but won't show me where a rating is missing for a picture. Thanks in advance!

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  • php mysql error beginner

    - by Marcelo
    Hi, I'm trying to print some values on the screen from a table but I having a problem, I don't know much about string, vector and array but I think that my problem is related to them. I'm getting this on the screen Fatal error: Cannot use [] for reading ... My code $sql="SELECT * FROM $tbl_name"; $result=mysql_query($sql) or trigger_error(mysql_error().$sql); while($row = mysql_fetch_array($result)){ $DATA = $row[]; } //line with probelm mysql_close(); //html part <table> <? foreach($DATA as $row): ?> <tr> <td><?=$row['id']?></td> //more stuff </tr> <? endforeach ?> </table> What I'm trying to do is print somevalues form a database. But I'm getting this error. I'm sorry for any mistake in English, and thanks in advance for any help.

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  • Mysql Query is not working, why?

    - by Furkan Kadioglu
    Im using this example: www.jtable.org Now i download to jtable php version. And i edited script. Jtable simple version is working but my edition is doesnt working. I can do list, but i cant do add a row; this codes having problem. But php doesnt giving any error. else if($_GET["action"] == "create") { //Insert record into database $result = mysql_query("INSERT INTO veriler(bolge, sehir, firma, adres, tel, web) VALUES('" . $_POST["bolge"] . "', '" . $_POST["sehir"] . "', '" . $_POST["firma"] . "', '" . $_POST["adres"] . "', '" . $_POST["tel"] . "', '" . $_POST["web"] . "'"); //Get last inserted record (to return to jTable) $result = mysql_query("SELECT * FROM veriler WHERE id = LAST_INSERT_ID();"); $row = mysql_fetch_array($result); //Return result to jTable $jTableResult = array(); $jTableResult['Result'] = "OK"; $jTableResult['Record'] = $row; print json_encode($jTableResult); } if you doesnt understand, please ask me question. Where is the problem?

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  • MySQL query problem

    - by Luke
    Ok, I have the following problem. I have two InnoDB tables: 'places' and 'events'. One place can have many events, but event can be created without entering place. In this case event's foreign key is NULL. Simplified structure of the tables looks as follows: CREATE TABLE IF NOT EXISTS `events` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) COLLATE utf8_bin NOT NULL, `places_id` int(9) unsigned DEFAULT NULL, PRIMARY KEY (`id`), KEY `fk_events_places` (`places_id`), ) ENGINE=InnoDB; ALTER TABLE `events` ADD CONSTRAINT `events_ibfk_1` FOREIGN KEY (`places_id`) REFERENCES `places` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION; CREATE TABLE IF NOT EXISTS `places` ( `id` int(9) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) COLLATE utf8_bin NOT NULL, PRIMARY KEY (`id`), ) ENGINE=InnoDB; Question is, how to construct query which contains name of the event and name of the corresponding place (or no value, in case there is no place assigned?). I am able to do it with two queries, but then I am visibly separating events which have place assigned from the ones that are without place. Help really appreciated.

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  • MySQL foreign key constraint disappearing

    - by Bramjam
    This is my table: /* oefenreeks leerplan */ CREATE TABLE leerplan_oefenreeks ( leerplan_oefenreeks_id INT PRIMARY KEY AUTO_INCREMENT NOT NULL, leerplan_id INT NOT NULL, oefenreeks_id INT NOT NULL, plaats INT NOT NULL ); /* fk */ ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT fk_leerp_oefenr_leerplan FOREIGN KEY(leerplan_id) REFERENCES leerplan (leerplan_id) ON DELETE CASCADE; ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT fk_leerp_oefenr_oefenreeks FOREIGN KEY(oefenreeks_id) REFERENCES oefenreeks (oefenreeks_id) ON DELETE CASCADE; /* when I execute the nexline, my fk_leerp_oefenr_leerplan constraint vanishes/disappears*/ ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT un_leerp_oefenr UNIQUE(leerplan_id, oefenreeks_id); ALTER TABLE leerplan_oefenreeks ADD CONSTRAINT un_leerp_oefenr_plaats UNIQUE(leerplan_id, plaats); When I go and check only 3 constraints exist. fk_leerp_oefenr_leerplan disappears. I don't understand why this happens.

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  • how to do reverse fulltext search in MySQL?

    - by Shore
    By default it's like this: select * from main_table where match(col1,col2) against('search_item'); but what I want to fetch is the reverse, say,I've restored all the search_item(1000 records,for example), and I want to see which of them matches a specified row in main_table. Is that doable?

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