Search Results

Search found 23901 results on 957 pages for 'mysql stored procedure'.

Page 415/957 | < Previous Page | 411 412 413 414 415 416 417 418 419 420 421 422  | Next Page >

  • Best way to run multiple queries per second on database, performance wise?

    - by Michael Joell
    I am currently using Java to insert and update data multiple times per second. Never having used databases with Java, I am not sure what is required, and how to get the best performance. I currently have a method for each type of query I need to do (for example, update a row in a database). I also have a method to create the database connection. Below is my simplified code. public static void addOneForUserInChannel(String channel, String username) throws SQLException { Connection dbConnection = null; PreparedStatement ps = null; String updateSQL = "UPDATE " + channel + "_count SET messages = messages + 1 WHERE username = ?"; try { dbConnection = getDBConnection(); ps = dbConnection.prepareStatement(updateSQL); ps.setString(1, username); ps.executeUpdate(); } catch(SQLException e) { System.out.println(e.getMessage()); } finally { if(ps != null) { ps.close(); } if(dbConnection != null) { dbConnection.close(); } } } And my DB connection private static Connection getDBConnection() { Connection dbConnection = null; try { Class.forName(DB_DRIVER); } catch (ClassNotFoundException e) { System.out.println(e.getMessage()); } try { dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER,DB_PASSWORD); return dbConnection; } catch (SQLException e) { System.out.println(e.getMessage()); } return dbConnection; } This seems to be working fine for now, with about 1-2 queries per second, but I am worried that once I expand and it is running many more, I might have some issues. My questions: Is there a way to have a persistent database connection throughout the entire run time of the process? If so, should I do this? Are there any other optimizations that I should do to help with performance? Thanks

    Read the article

  • Does table columns increase select statement execution time

    - by paokg4
    I have 2 tables, same structure, same rows, same data but the first has more columns (fields). For example: I select the same 3 fields from both of them (SELECT a,b,c FROM mytable1 and then SELECT a,b,c FROM mytable2) I've tried to run those queries on 100,000 records (for each table) but at the end I got the same execution time (0.0006 sec) Do you know if the number of the columns (and in the end the size of the one table is bigger than the other) has to do something with the query execution time?

    Read the article

  • Time diff calculations where date and time are in seperate columns

    - by pedalpete
    I've got a query where I'm trying to get the hours in duration (eg 6.5 hours) between two different times. In my database, time and date are held in different fields so I can efficiently query on just a startDate, or endDate as I never query specifically on time. My query looks like this SELECT COUNT(*), IFNULL(SUM(TIMEDIFF(endTime,startTime)),0) FROM events WHERE user=18 Sometimes an event will go overnight, so the difference between times needs to take into account the differences between the dates as well. I've been trying SELECT COUNT(*), IFNULL(SUM(TIMEDIFF(CONCAT(endDate,' ',endTime),CONCAT(startDate,' ',startTime))),0) FROM events WHERE user=18 Unfortunately I only get errors when I do this, and I can't seem to combine the two fields into a single timestamp.

    Read the article

  • how can we change the value by using radio buttons

    - by magna
    I am making a website in Adobe Dreamweaver with php. In the site there’s a 3 buttons for selecting payment method that will act as the continue button. What I want is when the user checks a radio buttons (I agree button), it will be add with that amount and display with previous amount.. there is three buttons which has the corresponding values(amount in pounds).. plz check my website http://www.spsmobile.co.uk in this linkgo to mobile phone unlocking and after add the cart click make payment it will go to next page there is a delivery mail details.. for that delivery mail details only am asking.. here i mentioned code: <input id="radio-1" type="radio" name="rmr" value="1"> <label for="radio-1">£3</label> <input id="radio-2" type="radio" name="rmr" value="2"> <label for="radio-2">£5.5</label> <input id="radio-3" type="radio" name="rmr" value="4"> <label for="radio-3">£10</label> <div class="total-text" style="font-size:36px">£10</div> var total = parseInt($("div.total-text").text().substring(1), 10); $("input[name='rmr']").bind('change', function() { var amount = 0; switch (this.value) { case "1": amount = 3; break; case "2": amount = 5.5; break; case "4": amount = 10; break; } $("div.total-text").text("£" + (total + amount)); }); but there is no change , my previous amount did not add with that. while am clicking previous amount only displayed on browser.. i need when i cliks radio button the value should change correspondingly.. where i did that mistake...plz give me some idea and what should i do..is there any need for storing db.. thanks in adv

    Read the article

  • how can i make sure only a single record is inserted when multiple apache threads are trying to acce

    - by Ed Gl
    I have a web service (xmlrpc service to be exact) that handles among other things writing data into the database. Here's the scenario: I often receive requests to either update or insert a record. What I would do is this: If the record already exists, append to the record, If not, create a new record The issue is that there are certain times I would get a 'burst' of requests, which spawns several apache threads to handle the request. These 'bursts' would come within less than milliseconds of each other. I now have several threads performing #1 and #2. Often two threads would would 'pass' number #1 and actually create two duplicate records (except for the primary key). I'd like to use some locking mechanism to prevent other threads from accessing the table while the other thread finishes its work. I'm just afraid of using it because if something happens I don't want to leave the table locked. Is there a solid way of handling this? I'm open to using locks if I can do it properly. Thanks,

    Read the article

  • Unique constraint not created in JPA

    - by homaxto
    I have created the following entity bean, and specified two columns as being unique. Now my problem is that the table is created without the unique constraint, and no errors in the log. Does anyone have an idea? @Entity @Table(name = "cm_blockList", uniqueConstraints = @UniqueConstraint(columnNames = {"terminal", "blockType"})) public class BlockList { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; @ManyToOne(cascade = CascadeType.PERSIST) @JoinColumn(name="terminal") private Terminal terminal; @Enumerated(EnumType.STRING) private BlockType blockType; private String regEx; }

    Read the article

  • Retrieve rows where a value exists within a comma separated list

    - by Klaaz
    I like to reverse this query: SELECT * FROM table WHERE status IN ( option,option1,option2 ); in a query like SELECT * FROM table WHERE status contains ( 'option' ); Where field 'status' column contains (by example): 'option,option1'. When I use SELECT * FROM table WHERE status LIKE '%option%' ); It also selects the rows with a 'status' column that only contains 'option1' Is this possible? example data: id,name,status 1,'test1','option,option1' 2,'test2','option,option2' 3,'test3','option2' 4,'test4','option2,option3' 5,'test5','option' SELECT * FROM table WHERE status contains ( 'option' ); This query should select select record 1,2 and 5. 'status' field type is varchar. The problem is that the status fields contains data that is almost alike, exept from the added number to option. Off course this is a made up example but the real thing has this kind of parameters

    Read the article

  • Calculate distances and sort them

    - by Emir
    Hi guys, I wrote a function that can calculate the distance between two addresses using the Google Maps API. The addresses are obtained from the database. What I want to do is calculate the distance using the function I wrote and sort the places according to the distance. Just like "Locate Store Near You" feature in online stores. I'm going to specify what I want to do with an example: So, lets say we have 10 addresses in database. And we have a variable $currentlocation. And I have a function called calcdist(), so that I can calculate the distances between 10 addresses and $currentlocation, and sort them. Here is how I do it: $query = mysql_query("SELECT name, address FROM table"); while ($write = mysql_fetch_array($query)) { $distance = array(calcdist($currentlocation, $write["address"])); sort($distance); for ($i=0; $i<1; $i++) { echo "<tr><td><strong>".$distance[$i]." kms</strong></td><td>".$write['name']."</td></tr>"; } } But this doesn't work very well. It doesn't sort the numbers. Another challenge: How can I do this in an efficient way? Imagine there are infinite numbers of addresses; how can I sort these addresses and page them?

    Read the article

  • Doctrine 1.2 Column Naming Conventions for Many To Many Relationships

    - by Alan Storm
    I'm working with an existing database schema, and trying to setup two Doctrine models with a Many to Many relationship, as described in this document When creating tables from scratch, I have no trouble getting this working. However, the existing join tables use a different naming convention that what's described in the Doctrine document. Specifically Table 1 -------------------------------------------------- table_1_id ....other columns.... Table 2 -------------------------------------------------- table_2_id ....other columns.... Join Table -------------------------------------------------- fktable1_id fktable_2_id Basically, the previous developers prefaced all forign keys with an fk. From the examples I've seen and some brief experimenting with code, it appears that Doctrine 1.2 requires that the join table use the same column names as the tables it's joining in Is my assumption correct? If so, has the situation changed in Doctrine 2? If the answers to either of the above are true, how do you configure the models so that all the columns "line up"

    Read the article

  • Getting highest results in a JOIN

    - by Keithamus
    I've got three tables; Auctions, Auction Bids and Users. The table structure looks something like this: Auctions: id title -- ----- 1 Auction 1 2 Auction 2 Auction Bids: id user_id auction_id bid_amt -- ------- ---------- ------- 1 1 1 200.00 2 2 1 202.00 3 1 2 100.00 Users is just a standard table, with id and user name. My aim is to join these tables so I can get the highest values of these bids, as well as get the usernames related to those bids; so I have a result set like so: auction_id auction_title auctionbid_amt user_username ---------- ------------- -------------- ------------- 1 Auction 1 202.00 Bidder2 2 Auction 2 100.00 Bidder1 So far my query is as follows: SELECT a.id, a.title, ab.bid_points, u.display_name FROM auction a LEFT JOIN auctionbid ab ON a.id = ab.auction_id LEFT JOIN users u ON u.id = ab.user_id GROUP BY a.id This gets the single rows I am after, but it seems to display the lowest bid_amt, not the highest.

    Read the article

  • self join to select consecutive numbers

    - by shantanuo
    CREATE TABLE `mybug` ( `SEAT_NO` decimal(2,0) NOT NULL, `ROW_NO` decimal(2,0) NOT NULL, `COL_NO` decimal(2,0) NOT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1; INSERT INTO `mybug` VALUES ('1','1','1'),('26','7','2'),('31','8','2'),('32','8','1'),('33','9','1'),('34','9','2'),('35','9','5'),('36','9','6'),('37','10','6'),('38','10','5'),('39','10','2'),('40','10','1'),('41','11','1'),('42','11','2'),('43','11','4'),('44','11','5'); +---------+--------+--------+ | SEAT_NO | ROW_NO | COL_NO | +---------+--------+--------+ | 1 | 1 | 1 | | 26 | 7 | 2 | | 31 | 8 | 2 | | 32 | 8 | 1 | | 33 | 9 | 1 | | 34 | 9 | 2 | | 35 | 9 | 5 | | 36 | 9 | 6 | | 37 | 10 | 6 | | 38 | 10 | 5 | | 39 | 10 | 2 | | 40 | 10 | 1 | | 41 | 11 | 1 | | 42 | 11 | 2 | | 43 | 11 | 4 | | 44 | 11 | 5 | +---------+--------+--------+ 16 rows in set (0.00 sec) In the above chart, I need to select 2 seats those are in the same row AND column numbers are next to each other. For e.g. Seat Numbers 38 & 39 can not be issued even if both the seats are from the same row because the column numbers 2 & 5 are not adjacent. The expected results are as follows: 31 33 35 37 39 41 43 These are the starting numbers and the next seat will be automatically booked as well. for e.g. 31 & 32

    Read the article

  • How much does an InnoDB table benefit from having fixed-length rows?

    - by Philip Eve
    I know that dependent on the database storage engine in use, a performance benefit can be found if all of the rows in the table can be guaranteed to be the same length (by avoiding nullable columns and not using any VARCHAR, TEXT or BLOB columns). I'm not clear on how far this applies to InnoDB, with its funny table arrangements. Let's give an example: I have the following table CREATE TABLE `PlayerGameRcd` ( `User` SMALLINT UNSIGNED NOT NULL, `Game` MEDIUMINT UNSIGNED NOT NULL, `GameResult` ENUM('Quit', 'Kicked by Vote', 'Kicked by Admin', 'Kicked by System', 'Finished 5th', 'Finished 4th', 'Finished 3rd', 'Finished 2nd', 'Finished 1st', 'Game Aborted', 'Playing', 'Hide' ) NOT NULL DEFAULT 'Playing', `Inherited` TINYINT NOT NULL, `GameCounts` TINYINT NOT NULL, `Colour` TINYINT UNSIGNED NOT NULL, `Score` SMALLINT UNSIGNED NOT NULL DEFAULT 0, `NumLongTurns` TINYINT UNSIGNED NOT NULL DEFAULT 0, `Notes` MEDIUMTEXT, `CurrentOccupant` TINYINT UNSIGNED NOT NULL DEFAULT 0, PRIMARY KEY (`Game`, `User`), UNIQUE KEY `PGR_multi_uk` (`Game`, `CurrentOccupant`, `Colour`), INDEX `Stats_ind_PGR` (`GameCounts`, `GameResult`, `Score`, `User`), INDEX `GameList_ind_PGR` (`User`, `CurrentOccupant`, `Game`, `Colour`), CONSTRAINT `Constr_PlayerGameRcd_User_fk` FOREIGN KEY `User_fk` (`User`) REFERENCES `User` (`UserID`) ON DELETE CASCADE ON UPDATE CASCADE, CONSTRAINT `Constr_PlayerGameRcd_Game_fk` FOREIGN KEY `Game_fk` (`Game`) REFERENCES `Game` (`GameID`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=INNODB CHARACTER SET utf8 COLLATE utf8_general_ci The only column that is nullable is Notes, which is MEDIUMTEXT. This table presently has 33097 rows (which I appreciate is small as yet). Of these rows, only 61 have values in Notes. How much of an improvement might I see from, say, adding a new table to store the Notes column in and performing LEFT JOINs when necessary?

    Read the article

  • How can I use cURL to open multiple URLs simultaneously with PHP?

    - by Rob
    Here is my current code: $SQL = mysql_query("SELECT url FROM urls") or die(mysql_error()); //Query the urls table while($resultSet = mysql_fetch_array($SQL)){ //Put all the urls into one variable // Now for some cURL to run it. $ch = curl_init($resultSet['url']); //load the urls curl_setopt($ch, CURLOPT_TIMEOUT, 2); //No need to wait for it to load. Execute it and go. curl_exec($ch); //Execute curl_close($ch); //Close it off } //While loop I'm relatively new to cURL. By relatively new, I mean this is my first time using cURL. Currently it loads one for two seconds, then loads the next one for 2 seconds, then the next. however, I want to make it load ALL of them at the same time. I'm sure its possible, I'm just unsure as to how. If someone could point me in the right direction, I'd appreciate it.

    Read the article

  • how do i release the auto increment serial nos that are missing

    - by mmdel
    i have a table with auto increment field and i am using transactions when inserting new data. now i find there are a few serial nos that are missing. suppose the last serial no was 475, now when i insert new row, the serial allotted to it is 481. how do i correct this. table_A fields ID(Auto increment),Name,Address table_B fields ID(Auto increment FK TO table_A ID),Tel,Fax,Email,Salesman table_C fields ID(Auto increment FK TO table_A ID),monthly_commitment mysql_query(BEGIN); $a = mysql_query("INSERT INTO table_A VALUES('','name','address')"); $b = mysql_query("INSERT INTO table_B VALUES('','tel','fax','email','salesman')"); $b = mysql_query("INSERT INTO table_C VALUES('','monthly commitment')"); if(($a) && ($b) && ($c)){mysql_query("COMMIT");} else {mysql_query("ROLLBACK");}

    Read the article

  • Unique constraint with nullable column

    - by Álvaro G. Vicario
    I have a table that holds nested categories. I want to avoid duplicate names on same-level items (i.e., categories with same parent). I've come with this: CREATE TABLE `category` ( `category_id` int(10) unsigned NOT NULL AUTO_INCREMENT, `category_name` varchar(100) NOT NULL, `parent_id` int(10) unsigned DEFAULT NULL, PRIMARY KEY (`category_id`), UNIQUE KEY `category_name_UNIQUE` (`category_name`,`parent_id`), KEY `fk_category_category1` (`parent_id`,`category_id`), CONSTRAINT `fk_category_category1` FOREIGN KEY (`parent_id`) REFERENCES `category` (`category_id`) ON DELETE SET NULL ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_spanish_ci Unluckily, category_name_UNIQUE does not enforce my rule for root level categories (those where parent_id is NULL). Is there a reasonable workaround?

    Read the article

  • How many indexes will actually get used?

    - by Ender
    I'm writing a page that does very simple search queries, resulting in something like: SELECT * FROM my_table WHERE A in (a1, a2, a3) AND B in (b1, b2) AND C in (c1, c2, c3, c4) AND And so on for a variable number of columns, usually ~5. If I create a separate index for each column (one for A, one for B, one for C, not (A,B,C)), will all of them be used in the above query?

    Read the article

  • How to create a better tables Structure.

    - by user160820
    For my website i have tables Category :: id | name Product :: id | name | categoryid Now each category may have different sizes, for that I have also created a table Size :: id | name | categoryid | price Now the problem is that each category has also different ingredients that customer can choose to add to his purchased product. And these ingredients have different prices for different sizes. For that I also have a table like Ingredient :: id | name | sizeid | categoryid | price I am not sure if this Structure really normalized is. Can someone please help me to optimize this structure and which indexed do i need for this Structure?

    Read the article

  • What is the best way to reduce code and loop through a hierarchial commission script?

    - by JM4
    I have a script which currently "works" but is nearly 3600 lines of code and makes well over 50 database calls within a single script. From my experience, there is no way to really "loop" the script and minimize it because each call to the database is a subquery of the ones before based on referral ids. Perhaps I can give a very simple example of what I am trying to accomplish and see if anybody has experience with something similar. In my example, there are three tables: Table 1 - Sellers ID | Comm_level | Parent ----------------------------------- 1 | 4 | NULL 2 | 3 | 1 3 | 2 | 1 4 | 2 | 2 5 | 2 | 2 6 | 1 | 3 Where ID is the id of one of our sales agents, comm_level will determine what his commission percentage is for each product he sells, parent indicates the ID for whom recruited that particular agent. In the example above, 1 is the top agent, he recruited two agents, 2 and 3. 2 recruited two agents, 4 and 5. 3 recruited one agent, 6. NOTE: An agent can NEVER recruit anybody equal to or higher than their own level. Table 2 - Commissions Level | Item 1 | Item 2 | Item 3 ----------------------------------------------------- 4 | .5 | .4 | .3 3 | .45 | .35 | .25 2 | .4 | .3 | .2 1 | .35 | .25 | .15 This table lays out the commission percentages for each agent based on their actual comm_level (if an agent is at a level 4, he will receive 50% on every item 1 sold, 40% on every item 2, 30% on every item 3 and so on. Table 3 - Items Sold ID | Item --------------------- 4 | item_1 4 | item_2 1 | item_1 2 | item_3 6 | item_2 1 | item_3 This table pairs the actual item sold with the seller who sold the item. When generating the commission report, calculating individual values is very simple. Calculating their commission based on their sub_sellers however is very difficult. In this example, Seller ID 1 gets a piece of every single item sold. The commission percentages indicate individual sales or the height of their commission. For example: When seller ID 6 sold one of item_2 above, the tree for commissions will look like the following: -ID 6 - 25% of cost(item_1) -ID 3 - 5% of cost(item_1) - (30% is his comm - 25% comm of seller id 6) -ID 1 - 10% of cost(item_1) - (40% is his comm - 30% of seller id 3) This must be calculated for every agent in the system from the top down (hence the DB calls within while loops throughout my enormous script). Anybody have a good suggestion or samples they may have used in the past?

    Read the article

  • group by with 3 diffrent

    - by NN
    I have 2 table and I wanna a query with 3 column result in on of them 2 column with view count and title name and in the other 1 column with type_ and i wanna to grouping type_ with max(view count) and show the them title but i didn't have any idea about grouping expression. i think we can solve in by using sub query but i don't know which column use in group by. 2 table join with this expression class pk=resource key i exam this query: SELECT t.title,j.type_ FROM tags asset t,journal article j where type_ in (select type_ from journal article,tags asset where class pk=resource key group by type_) but the answer was wrong

    Read the article

< Previous Page | 411 412 413 414 415 416 417 418 419 420 421 422  | Next Page >