Search Results

Search found 14874 results on 595 pages for 'mysql connector'.

Page 168/595 | < Previous Page | 164 165 166 167 168 169 170 171 172 173 174 175  | Next Page >

  • do's and don'ts for writing mysql queries

    - by nik
    One thing I always wonder while writing query is that am I writing most optimized query or not? I know certain things like: 1) using SELECT field1, filed2 instead of SELECT * 2) Giving proper indexes to the tables but I am sure there are more things that should be kept in mind for writing queries, since most of the database can only grow more and optimal query will help gr8 in execution time, Can u share some tips and tricks on writing queries?

    Read the article

  • MySQL - Finding time overlaps

    - by Jude
    Hi, I have 2 tables in the database with the following attributes: Booking ======= booking_id booking_start booking_end resource_booked =============== booking_id resource_id The second table is an associative entity between "Booking" and "Resource" (i.e., 1 booking can contain many resources). Attributes booking_start and booking_end are timestamps with date and time in it. May I know how I might be able to find out for each resource_id (resource_booked) if the date/time overlaps or clashes with other bookings of similar resource_id? I was doodling the answer on paper, pictorially, to see if it might help me visualize how I could solve this and I got this: Joining the 2 tables (Booking, Booked_resource) into one table with the 4 attributes needed. Follow the answer suggested here : http://stackoverflow.com/questions/689458/find-overlapping-date-time-rows-within-one-table I did step 1 but step 2 is leaving me baffled! I would really appreciate any help on this! Thanks!

    Read the article

  • Mysql InnoDB performance optimization and indexing

    - by Davide C
    Hello everybody, I have 2 databases and I need to link information between two big tables (more than 3M entries each, continuously growing). The 1st database has a table 'pages' that stores various information about web pages, and includes the URL of each one. The column 'URL' is a varchar(512) and has no index. The 2nd database has a table 'urlHops' defined as: CREATE TABLE urlHops ( dest varchar(512) NOT NULL, src varchar(512) DEFAULT NULL, timestamp timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, KEY dest_key (dest), KEY src_key (src) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 Now, I need basically to issue (efficiently) queries like this: select p.id,p.URL from db1.pages p, db2.urlHops u where u.src=p.URL and u.dest=? At first, I thought to add an index on pages(URL). But it's a very long column, and I already issue a lot of INSERTs and UPDATEs on the same table (way more than the number of SELECTs I would do using this index). Other possible solutions I thought are: -adding a column to pages, storing the md5 hash of the URL and indexing it; this way I could do queries using the md5 of the URL, with the advantage of an index on a smaller column. -adding another table that contains only page id and page URL, indexing both columns. But this is maybe a waste of space, having only the advantage of not slowing down the inserts and updates I execute on 'pages'. I don't want to slow down the inserts and updates, but at the same time I would be able to do the queries on the URL efficiently. Any advice? My primary concern is performance; if needed, wasting some disk space is not a problem. Thank you, regards Davide

    Read the article

  • MySQL: Complex Join Statement involving two tables and a third correlation table

    - by Stephen
    I have two tables that were built for two disparate systems. I have records in one table (called "leads") that represent customers, and records in another table (called "manager") that are the exact same customers but "manager" uses different fields (For example, "leads" contains an email address, and "manager" contains two fields for two different emails--either of which might be the email from "leads"). So, I've created a correlation table that contains the lead_id and manager_id. currently this correlation table is empty. I'm trying to query the "leads" table to give me records that match either "manager" email field with the single "leads" email field, while at the same time ignoring fields that have already been added to the "correlated" table. (this way I can see how many leads that match have not yet been correlated.) Here's my current, invalid SQL attempt: SELECT leads.id, manager.id FROM leads, manager LEFT OUTER JOIN correlation ON correlation.lead_id = leads.id WHERE correlation.id IS NULL AND leads.project != "someproject" AND (manager.orig_email = leads.email OR manager.dest_email = leads.email) AND leads.created BETWEEN '1999-01-01 00:00:00' AND '2010-05-10 23:59:59' ORDER BY leads.created ASC; I get the error: Unknown column 'leads.id' in 'on clause' Before you wonder: there are records in the "leads" table where leads.project != "someproject" and leads.created falls between those dates. I've included those additional parameters for completeness.

    Read the article

  • Problem importing mysql triggers generated from mysqldump

    - by OM The Eternity
    I am using phpmyadmin for using the mysqldump query, but as per my requirement i have to create a new database which is clone of the previous one, now in this case when i import the main DB it contain all the trigger information as well with the DB name mentioned in it.. As i import this DB to new one my triggers get imported as well but the trigger_schema are not changed as per new DB.. What could be done to get resolve this problem?

    Read the article

  • Non distinct Unique ID in MySQL database table.

    - by Geoff
    First of, a simplified version: I am wondering if I can create a trigger to activate during INSERT (it's actually LOAD DATA INFILE) and NOT enter records for an RMA already in my table? I have a table that has no records that are unique. Some may be duplicates but there is one field that I can use to know if the data has been entered or not. For instance RMA Op Days --------------------- 213 Repair 0.10 213 Test 0.20 213 Repair 0.10 So I could do an index on the three columns together but as you see it's possible for an RMA to be in a step for the same amount of time twice so it's possible to have duplicate records. This data comes from a report that I cannot edit and this is all it provides. The key is that an RMA's data is only in the report once so if my database already has that RMA in it's records I want to skip the loading of that RMA's records from the report. By all means please let me know if that didn't make sense, I'll Explain as needed. I'm sure it's not uncommon but I couldn't find anything on the net.

    Read the article

  • getting a date array from a mysql database?

    - by user296516
    Hi guys, I have a database with date field is this format "2010.06.11. | 10:26 13" What is need is a php array that would hold all the different dates, .i.e. array[0] = "2010.06.09." array[1] = "2010.06.10." array[2] = "2010.06.11." Currently I am doing it by selecting the whole table, then looping through the result and adding the date substr to an array if it is not already there. But maybe there is a faster way? Thanks.

    Read the article

  • mysql join Two tables to get records

    - by Saranya
    Hai guys, I have two tables Incharge and property. My property table has three fields 1stIncharge,2ndIncharge and 3rdIncharge. InchargeId is set as foreign key for all the above fields in the property table.. How to write a select statement that joins both the table.. I ve tried a bit but no result select P.Id,P.Name,P.1stIncharge,P.2ndIncharge,P.3rdIncharge,I.Id from Property as P join Incharge as I where (\\How to give condition here \\) Guys 3 fields P.1stIncharge, P.2ndIncharge, P.3rdIncharge has foreign key I.Id Edit: select P.Id,P.Name,P.1stIncharge,P.2ndIncharge,P.3rdIncharge,I1.Id from Property as P inner join Incharge as I1 on I1.Id=P.1stIncharge inner join Incharge as I2 on I2.Id=P.2ndIncharge inner join Incharge as I3 on I3.Id=P.3rdIncharge and this query working

    Read the article

  • MySQL database design question

    - by Greelmo
    I'm trying to weigh the pros and cons of a database design, and would like to get some feedback as to the best approach. Here is the situation: I have users of my system that have only a few required items (username, password). They can then supply a lot of optional information. This optional information continues to grow as the system grows, so I want to do it in such a way that adding new optional information is easy. Currently, I have a separate table for each piece of information. For example, there's a table called 'names' that holds 'user_id', 'first_name', and 'last_name'. There's 'address', 'occupation', etc. You get the drift. In most cases, when I talk to my database, I'm looking only for users with one particular qualifier (name, address, etc.). However, there are instances when I want to see what information a user has set. The 'edit account' page, for example, must run queries for each piece of information it wants. Is this wasteful? Is there a way I can structure my queries or my database to make it so I never have to do one query for each piece of information like that without getting my tables to huge? If i want to add 'marital status', how hard will that be if I don't have a one-table-per-attribute system? Thanks in advance.

    Read the article

  • Show last 4 table entries mysql php

    - by user272899
    I have a movie database Kind of like a blog and I want to display the last 4 created entries. I have a column in my table for timestamp called 'dateadded'. Using this code how would I only display the 4 most recent entries to table <?php //connect to database mysql_connect($mysql_hostname,$mysql_user,$mysql_password); @mysql_select_db($mysql_database) or die("<b>Unable to connect to specified database</b>"); //query databae $query = "SELECT * FROM movielist"; $result=mysql_query($query) or die('Error, insert query failed'); $row=0; $numrows=mysql_num_rows($result); while($row<$numrows) { $id=mysql_result($result,$row,"id"); $imgurl=mysql_result($result,$row,"imgurl"); $imdburl=mysql_result($result,$row,"imdburl"); ?> <div class="moviebox rounded"><a href="http://<?php echo $domain; ?>/viewmovie?movieid=<?php echo $id; ?>" rel="facebox"> <img src="<?php echo $imgurl; ?>" /> <form method="get" action=""> <input type="text" name="link" class="link" style="display:none" value="http://us.imdb.com/Title?<?php echo $imdburl; ?>"/> </form> </a></div> <?php $row++; } ?>

    Read the article

  • Help with MySQL Query using CASE statement

    - by hairdresser-101
    I am trying to group a number of customers together based on their "Head Office" or "Parent" location. THis works ok except for a flaw which I didn't forsee when I was developing my system... For customers that did not have a "Parent" (standalone business) I defaulted the parent_id to 0. Therefore, my data would look like this: id parent_id customer 1 0 CustName#1 2 4 CustName#2 - Melbourne 3 4 CustName#2 - Sydney 4 0 CustName#2 (Head Office) What I want to do is Group my results together so that I have one row for CustName#1 and one row for CustName#2 BUT my problem is that there is no parent record for parent_id=0 and these rows are being excluded when using an inner join. I've tried using a case statement but that is not working either (parents are still being ignored) Any help would be greatly appreciated. Here is my query (My CASE is basically trying to get the business_name from the customer table based on the parent_id EXCEPT when the parent_id = 0, THEN just use the customer_name that is listed in the job_summary table): SELECT js.month_of_year, (CASE js.parent_id WHEN 0 THEN js.customer_name ELSE c.business_name END) as customer, SUM(js.jobs), SUM(js.total_cost), sum(js.total_sell) FROM JOB_SUMMARY js INNER JOIN customer c on js.parent_id=c.id group by js.month_of_year, (CASE c.parent_id WHEN 0 THEN js.customer_name ELSE c.business_name END) ORDER BY `customer` ASC

    Read the article

  • Newbie question - MySQL index size

    - by Tommy
    I've just started to investigating how I should optimize my database. Indexing seems to be a good idea, so I want to index a VARCHAR column, the engine is MyISAM. From what I've read, I understand that an index is limited to a size of 1000 bytes. A VARCHAR character is 3 bytes in size. Does this mean that if I want to index a VARCHAR column with 50 rows, I need an index prefix of 6 characters? I came to that number by dividing 1000 with the row number 50, then the bytesize per character that is 3. 1000/50/3=6,66. It seems a little complicated, so I'm just wondering if I'm thinking right? It seems weird to me that you'd only be able to index 333 rows in a VARCHAR column, using a prefix of 1 character.

    Read the article

  • MySQL search Chinese characters

    - by Jasie
    Hello, Let's say I have a row: ??????? Someone enters as a query: ?? Should I break up the characters in the query, and individually perform a LIKE % % match on each character against the row, or is there any easier way to get a row that contains one of the two characters? FULLTEXT won't work with CJK characters. Thanks!

    Read the article

  • JDBC with MySQL

    - by Josh K
    I'm working on getting my database to talk to my Java programs. What do I need to get started? Having already read through (and been thoroughly confused, something that does not happen often) with some other turorials I figured I'd best ask here. How do I import a jar file from the local directory? Can someone give me a quick and dirty sample program using the JDBC?

    Read the article

  • MySQL: updating a row and deleting the original in case it becomes a duplicate

    - by Silvio Donnini
    I have a simple table made up of two columns: col_A and col_B. The primary key is defined over both. I need to update some rows and assign to col_A values that may generate duplicates, for example: UPDATE `table` SET `col_A` = 66 WHERE `col_B` = 70 This statement sometimes yields a duplicate key error. I don't want to simply ignore the error with UPDATE IGNORE, because then the rows that generate the error would remain unchanged. Instead, I want them to be deleted when they would conflict with another row after they have been updated I'd like to write something like: UPDATE `table` SET `col_A` = 66 WHERE `col_B` = 70 ON DUPLICATE KEY REPLACE which unfortunately isn't legal in SQL, so I need help finding another way around. Also, I'm using PHP and could consider a hybrid solution (i.e. part query part php code), but keep in mind that I have to perform this updating operation many millions of times. thanks for your attention, Silvio Reminder: UPDATE's syntax has problems with joins with the same table that is being updated

    Read the article

  • Php fetch rows from multiple MySQL tables

    - by Jon McIntosh
    Right now I am fetching all of the rows from one of my tables: query = "SELECT * FROM thread WHERE threadid = 2 ORDER BY threadid DESC"; $result = mysql_query($query); $num_rows = mysql_num_rows($result); if((!is_bool($result) || $result) && $num_rows) { while($row = mysql_fetch_array($result)) { $thread = $row['title']; $threadID = $row['threadid']; $poster = $row['postusername']; } What I want to do is go to another table on my database: "post_display", and get the row 'text' where the threadid = 2.

    Read the article

  • compare string to date on mysql

    - by Mercer
    hello, i have a table with a date, this date is a string i want to compare this string with a date in my request. SELECT FE_CLIENT.* FROM FE_CLIENT WHERE D_DATFINPUBLI < '2010/06/03' How can i cast my column date_deb to a date for compare ..?

    Read the article

  • double left MYSQL join?

    - by Haroldo
    I've been trying left joins but as there are 2 joins, i think the problem is the 2nd join roots from table_B not table_A. i am not getting any results where there is the required data in the db. I am not getting a query error the query (simplified) SELECT events.*, ven.*, events_genres.* FROM events LEFT JOIN ven //OPTIONAL JOIN ON events.ven_id = ven.ven_id //OPTIONAL JOIN LEFT JOIN events_genres //REQUIRED JOIN ON events.event_id = events_genres.event_id //REQUIRED JOIN WHERE events.date >= '$this->now' AND WHERE events_genres.g_id = $g_id //REQUIRED MATCH ORDER BY date ven = optional, i'll have the info if its there. events_genres = required, i dont want any results that do not have a genre

    Read the article

  • Use of HAVING in MySQL

    - by KBrian
    I have a table from which I need to select all persons that have a first name that is not unique and that that set should be selected only if among the persons with a similar first name, all have a different last name. Example: FirstN LastN Bill Clinton Bill Cosby Bill Maher Elvis Presley Elvis Presley Largo Winch I want to obtain FirstN LastN Bill Clinton or FirstN LastN Bill Clinton Bill Cosby Bill Maher I tried this but it does not return what I want. SELECT * FROM Ids GROUP BY FirstN, LastN HAVING (COUNT(FirstN)>1 AND COUNT(LastN)=1)) [Edited my post after Aleandre P. Lavasseur remark]

    Read the article

  • MySQL - display rows of names and addresses grouped by name, where name occures more than once

    - by Stoob
    I have two tables, "name" and "address". I would like to list the last_name and joined address.street_address of all last_name in table "name" that occur more than once in table "name". The two tables are joined on the column "name_id". The desired output would appear like so: 213 | smith | 123 bluebird | 14 | smith | 456 first ave | 718 | smith | 12 san antonia st. | 244 | jones | 78 third ave # 45 | 98 | jones | 18177 toronto place | Note that if the last_name "abernathy" appears only once in table "name", then "abernathy" should not be included in the result. This is what I came up with so far: SELECT name.name_id, name.last_name, address.street_address, count(*) FROM `name` JOIN `address` ON name.name_id = address.name_id GROUP BY `last_name` HAVING count(*) > 1 However, this produces only one row per last name. I'd like all the last names listed. I know I am missing something simple. Any help is appreciated, thanks!

    Read the article

  • Getting mysql row that doesn't conflict with another row

    - by user939951
    I have two tables that link together through an id one is "submit_moderate" and one is "submit_post" The "submit_moderate" table looks like this id moderated_by post 1 James 60 2 Alice 32 3 Tim 18 4 Michael 60 Im using a simple query to get data from the "submit_post" table according to the "submit_moderate" table. $get_posts = mysql_query("SELECT * FROM submit_moderate WHERE moderated_by!='$user'"); $user is the person who is signed in. Now my problem is when I run this query, with the user 'Michael' it will retrieve this 1 James 60 2 Alice 32 3 Tim 18 Now technically this is correct however I don't want to retrieve the first row because 60 is associated with Michael as well as James. Basically I don't want to retrieve that value '60'. I know why this is happening however I can't figure out how to do this. I appreciate any hints or advice I can get.

    Read the article

  • mysql concat all field table

    - by hafizan
    Is there a way we can concat all field in the table(1 sql statement)(automatic) ? The reason was before user updated or delete a record,the record will push to another table for future reference.

    Read the article

  • mySQL not saving data?

    - by tony noriega
    i have a PHP contact form that submits data, and an email...: <?php $dbh=mysql_connect ("localhost", "username", "password") or die ('I cannot connect to the database because: ' . mysql_error()); mysql_select_db ("guest"); if (isset($_POST['submit'])) { if (!$_POST['name'] | !$_POST['email']) { echo"<div class='error'>Error<br />Please provide your Name and Email Address so we may properly contact you.</div>"; } else { $age = $_POST['age']; $name = $_POST['name']; $gender = $_POST['gender']; $email = $_POST['email']; $phone = $_POST['phone']; $comments = $_POST['comments']; $query = "INSERT INTO contact_us (age,name,gender,email,phone,comments) VALUES ('$age','$name','$gender','$email','$phone','$comments')"; mysql_query($query); mysql_close(); $yoursite = "Mysite "; $youremail = $email; $subject = "Website Guest Contact Us Form"; $message = "$name would like you to contact them Contact PH: $phone Email: $email Age: $age Gender: $gender Comments: $comments"; $email2 = "[email protected]"; mail($email2, $subject, $message, "From: $email"); echo"<div class='thankyou'>Thank you for contacting us,<br /> we will respond as soon as we can.</div>"; } } ?> The email is coming through fine, but the data is not storing the dbase... am i missing something? Its the same script as i use on another contact us page, only difference is instead of parsing the data on teh same page, i now send this data to a "thankyou.php" page... i tried changing $_POST to $_GET but that killed the page... what am i doing wrong?

    Read the article

  • Mysql - What's wrong with the query...?

    - by SpikETidE
    Hi everybody.... I am trying to query a database to find the following If a customer searches for a hotel in a city between dates A and B, find and return the hotels in which rooms are free between the two dates. There will be more than one room in each room type(i.e. 5 Rooms in type A, 10 rooms in Type B etc) and we have to query the db to find only those hotels in which there is atleast one room free in atleast one type. This is my table structure.... **Structure for table 'reservations'** reservation_id hotel_id room_id customer_id payment_id no_of_rooms check_in_date check_out_date reservation_date **Structure for table 'hotels'** hotel_id hotel_name hotel_description hotel_address hotel_location hotel_country hotel_city hotel_type hotel_stars hotel_image hotel_deleted **Structure for table 'rooms'** room_id hotel_id room_name max_persons total_rooms room_price room_image agent_commision room_facilities service_tax vat city_tax room_description room_deleted And this is my query $city_search = '15'; $check_in_date = '29-03-2010'; $check_out_date = '31-03-2010'; $dateFormat_check_in = "DATE_FORMAT('$reservations.check_in_date','%d-%m-%Y')"; $dateFormat_check_out = "DATE_FORMAT('$reservations.check_out_date','%d-%m-%Y')"; $dateCheck = "$dateFormat_check_in >= '$check_in_date' AND $dateFormat_check_out <= '$check_out_date'"; $query = "SELECT $rooms.room_id, $rooms.room_name, $rooms.max_persons, $rooms.room_price, $hotels.hotel_id, $hotels.hotel_name, $hotels.hotel_stars, $hotels.hotel_type FROM $hotels,$rooms,$reservations WHERE $hotels.hotel_city = '$city_search' AND $hotels.hotel_id = $rooms.hotel_id AND $hotels.hotel_deleted = '0' AND $rooms.room_deleted = '0' AND $rooms.total_rooms - (SELECT SUM($reservations.no_of_rooms) as tot FROM $reservations WHERE $dateCheck GROUP BY $reservations.room_id) > '0'"; The number of rooms already reserved in each room type in each hotel will be stored in the reservations table... The thing is the query doesn't return any result at all...even though it should if i calculate it myself manually... I tried running the sub-query alone and i don't get any result... And i have lost quite some amount of hair trying to de-bug this query from yesterday... What's wrong with this...? Or is there a better way to do what i mentioned above...? Thanks for your time... Edit : Code edited to remove an bud... thanks to

    Read the article

< Previous Page | 164 165 166 167 168 169 170 171 172 173 174 175  | Next Page >