Search Results

Search found 31421 results on 1257 pages for 'entity sql'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 716/1257 | < Previous Page | 712 713 714 715 716 717 718 719 720 721 722 723  | Next Page >

  • sql boolean truth test: zero OR null

    - by AK
    Is there way to test for both 0 and NULL with one equality operator? I realize I could do this: WHERE field = 0 OR field IS NULL But my life would be a hundred times easier if this would work: WHERE field IN (0, NULL) (btw, why doesn't that work?) I've also read about converting NULL to 0 in the SELECT statement (with COALESCE). The framework I'm using would also make this unpleasant. Realize this is oddly specific, but is there any way to test for 0 and NULL with one WHERE predicate?

    Read the article

  • mysql: get all rows into 1 column

    - by andufo
    hi, i have 3 tables: post (id_post, title) tag (id_tag, name) post_tag (id_post_tag, id_post, id_tag) Lets suppose that id_post 3 has 4 linked tags 1,2,3,4 (soccer, basket, tennis and golf). Is there a way to return something like this in ONE row? col 1 id_post = 3 col 2 tags = soccer basket tennis golf Thanks

    Read the article

  • Does normalization really hurt performance in high traffic sites?

    - by Luke101
    I am designing a database and I would like to normalize the database. I one query I will joining about 30-40 tables. Will this hurt the website performance if it ever becomes extremely popular? This will be the main query and it will be getting called 50% of the time. The other queries I will be joining about 2 tables. I have a choice right now to normalize or not to normalize but if the normalization becomes a problem in the future i may have to rewrite 40% of the software and it may take me a long time. Does normalization really hurt in this case? Should I denormalize now while I have the time?

    Read the article

  • explain these select statements!

    - by user329820
    Hi, I can not get the difference betwwn these statements? would you please help me,I have read some sample of select statements but I did not get these ones. SELECT 'B' FROM T WHERE A = (SELECT NULL); SELECT 'C' FROM T WHERE A = ANY (SELECT NULL); SELECT 'D' FROM T WHERE A = A; I use MySQL

    Read the article

  • MySQL left outer join is slow

    - by Ryan Doherty
    Hi, hoping to get some help with this query, I've worked at it for a while now and can't get it any faster: SELECT date, count(id) as 'visits' FROM dates LEFT OUTER JOIN visits ON (dates.date = DATE(visits.start) and account_id = 40 ) WHERE date >= '2010-12-13' AND date <= '2011-1-13' GROUP BY date ORDER BY date ASC That query takes about 8 seconds to run. I've added indexes on dates.date, visits.start, visits.account_id and visits.start+visits.account_id and can't get it to run any faster. Table structure (only showing relevant columns in visit table): create table visits ( `id` int(11) NOT NULL AUTO_INCREMENT, `account_id` int(11) NOT NULL, `start` DATETIME NOT NULL, `end` DATETIME NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; CREATE TABLE `dates` ( `date` date NOT NULL, PRIMARY KEY (`date`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; dates table contains all days from 2010-1-1 to 2020-1-1 (~3k rows). visits table contains about 400k rows dating from 2010-6-1 to yesterday. I'm using the date table so the join will return 0 visits for days there were no visits. Results I want for reference: +------------+--------+ | date | visits | +------------+--------+ | 2010-12-13 | 301 | | 2010-12-14 | 356 | | 2010-12-15 | 423 | | 2010-12-16 | 332 | | 2010-12-17 | 346 | | 2010-12-18 | 226 | | 2010-12-19 | 213 | | 2010-12-20 | 311 | | 2010-12-21 | 273 | | 2010-12-22 | 286 | | 2010-12-23 | 241 | | 2010-12-24 | 149 | | 2010-12-25 | 102 | | 2010-12-26 | 174 | | 2010-12-27 | 258 | | 2010-12-28 | 348 | | 2010-12-29 | 392 | | 2010-12-30 | 395 | | 2010-12-31 | 278 | | 2011-01-01 | 241 | | 2011-01-02 | 295 | | 2011-01-03 | 369 | | 2011-01-04 | 438 | | 2011-01-05 | 393 | | 2011-01-06 | 368 | | 2011-01-07 | 435 | | 2011-01-08 | 313 | | 2011-01-09 | 250 | | 2011-01-10 | 345 | | 2011-01-11 | 387 | | 2011-01-12 | 0 | | 2011-01-13 | 0 | +------------+--------+ Thanks in advance for any help!

    Read the article

  • Select 2 Rows from Table when COUNT of another table

    - by Marcus
    Here is the code that I currently have: SELECT `A`.* FROM `A` LEFT JOIN `B` ON `A`.`A_id` = `B`.`value_1` WHERE `B`.`value_2` IS NULL AND `B`.`userid` IS NULL ORDER BY RAND() LIMIT 2 What it currently is supposed to do is select 2 rows from A when the 2 rows A_id being selected are not in value_1 or value_2 in B. And the rows in B are specific to individual users with userid. What I need to do is make it also so that also checks if there are already N rows in B matching a A_id (either in value_1, or value_2) and userid, and if there are more than N rows, it doesn't select the A row.

    Read the article

  • Converting delimited string to multiple values in mysql

    - by epo
    I have a mysql legacy table which contains an client identifier and a list of items, the latter as a comma-delimited string. E.g. "xyz001", "foo,bar,baz". This is legacy stuff and the user insists on being able to edit a comma delimited string. They now have a requirement for a report table with the above broken into separate rows, e.g. "xyz001", "foo" "xyz001", "bar" "xyz001", "baz" Breaking the string into substrings is easily doable and I have written a procedure to do this by creating a separate table, but that requires triggers to deal with deletes, updates and inserts. This query is required rarely (say once a month) but has to be absolutely up to date when it is run, so e.g. the overhead of triggers is not warranted and scheduled tasks to create the table might not be timely enough. Is there any way to write a function to return a table or a set so that I can join the identifier with the individual items on demand?

    Read the article

  • Get the first and last posts in a thread

    - by Grampa
    I am trying to code a forum website and I want to display a list of threads. Each thread should be accompanied by info about the first post (the "head" of the thread) as well as the last. My current database structure is the following: threads table: id - int, PK, not NULL, auto-increment name - varchar(255) posts table: id - int, PK, not NULL, auto-increment thread_id - FK for threads The tables have other fields as well, but they are not relevant for the query. I am interested in querying threads and somehow JOINing with posts so that I obtain both the first and last post for each thread in a single query (with no subqueries). So far I am able to do it using multiple queries, and I have defined the first post as being: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id LIMIT 0, 1 The last post is pretty much the same except for ORDER BY id DESC. Now, I could select multiple threads with their first or last posts, by doing: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id GROUP BY t.id But of course I can't get both at once, since I would need to sort both ASC and DESC at the same time. What is the solution here? Is it even possible to use a single query? Is there any way I could change the structure of my tables to facilitate this? If this is not doable, then what tips could you give me to improve the query performance in this particular situation?

    Read the article

  • SQL query INSERT not working inserting values into my DB.

    - by Aiden Ryan
    Hello, I'm trying to insert registration data into a database but my php code isn't inserting the values into the DB although I'm not getting any errors either, can someone help me? this is the code i'm currently using: $connect = mysql_connect("localhost","myusername","mypassword"); mysql_select_db("application"); $queryreg = mysql_query('INSERT INTO users("username","password","email","date") VALUES("$username","$password","$email","$date")'); die ("You Have Been Registered."); I just need to add the username password email and date into the fields i have specified but it won't work, please someone help!

    Read the article

  • SqlException: Login failed for user

    - by Younes
    I use a dbml for my Data Access Layer to provide the data that i need in my app. When i connect from the server explorer everything seems fine. I choose to use my windows authentication and the connection test shows everything works just fine. When i Build my solution and run it on my IIS it says that i'm using a login that is not working. How to solve this issue?

    Read the article

  • Check for active connection in NHibernate

    - by Dofs
    I have a system with a few different databases, and I would like to check if a certain database is down, and if so display a message to the user. Is it possible in NHibernate to check if there is an active connection to the database, without having to request data and then catch the exception?

    Read the article

  • Service Broker not working after database restore

    - by roryok
    Have a working Service Broker set up on a server, we're in the process of moving to a new server but I can't seem to get Service Broker set up on the new box. Have done the obvious (to me) things like Enabling Broker on the DB, dropping the route, services, contract, queues and even message type and re adding them, setting ALTER QUEUE with STATUS ON SELECT * FROM sys.service_queues gives me a list of the queues, including my own two, which show as activation_enabled, receive_enabled etc. Needless to say the queues aren't working. When I drop messages into them nothing goes in and nothing comes out. Any ideas? I'm sure there's something really obvious I've missed...

    Read the article

  • Nested and complicated select statement

    - by Selase
    What i want to do here is simple...display an ivestigators ID and him corresponding name... That can be easily done from the users table by selecting based on the user type. However i want to select only some type of investigators. The analogy here is investigators are assigned to an exhibit for them to investigate. One investigator can be assigned to a maximum of 3 cases only. Now during the assigning of investigators, i want to write a select statement that would retrieve only investigatorID's that have been assigned to less than or equal to 2 cases. I have included exhibit and users table that shows sample data below. Now i sort of have an idea that i will have to first of all pick out all the investigators by their ID from the users list and then filter them through the exhibit table by dropping those assigned to 3 cases and leaving just those with two cases. then afterwards i use this IDs to select the Investigators name. the big questions is how do i write the statement??

    Read the article

  • Does Table.InsertOnSubmit create a copy of the original table?

    - by Bryan
    Using InsertOnSubmit seems to have some memory overhead. I have a System.Data.Linq.Table<User> table. When I do table.InsertOnSubmit(user) and then int count = table.Count(), the memory usage of my application increases by roughly the size of the User table, but the count is the number of items before user was inserted. So I'm guess an enumeration after InsertOnSubmit will create a copy of the table. Is that true?

    Read the article

  • Union Distinct rows but order them by number of occurrences in mysql

    - by Baversjo
    Hi I have the following query: SELECT o.id,o.name FROM object o WHERE ( o.description LIKE '%Black%' OR o.name LIKE '%Black%' ) UNION ALL SELECT o2.id,o2.name FROM object o2 WHERE ( o2.description LIKE '%iPhone%' OR o2.name LIKE '%iPhone%' ) Which procude the following: id name 2 New Black iPhone 1 New White iPhone 2 New Black iPhone I would like to UNION DISTINCT, but I would also like the result ordered by the number of occurrences of each identical row (primary: id).

    Read the article

  • Strange use of the index in Mysql

    - by user309067
    explain SELECT feed_objects.* FROM feed_objects WHERE (feed_objects.feed_id IN (165,160,159,158,157,153,152,151,150,149,148,147,129,128,127,126,125,124,122,121,120,119,118,117,116,115,114,113,111,110)) ; +----+-------------+--------------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | feed_objects | ALL | by_feed_id | NULL | NULL | NULL | 188 | Using where | +----+-------------+--------------+------+---------------+------+---------+------+------+-------------+ Not used index 'by_feed_id' But when I point less than the values in the "WHERE" - everything is working right explain SELECT feed_objects.* FROM feed_objects WHERE (feed_objects.feed_id IN (165,160,159,158,157,153,152,151,150,149,148,147,129,128,127,125,124)) ; +----+-------------+--------------+-------+---------------+------------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------+-------+---------------+------------+---------+------+------+-------------+ | 1 | SIMPLE | feed_objects | range | by_feed_id | by_feed_id | 9 | NULL | 18 | Using where | +----+-------------+--------------+-------+---------------+------------+---------+------+------+-------------+ Used index 'by_feed_id' What is the problem?

    Read the article

  • sqlite3.OperationalError: database is locked - non-threaded application

    - by James C
    Hi, I have a Python application which throws the standard sqlite3.OperationalError: database is locked error. I have looked around the internet and could not find any solution which worked (please note that there is no multiprocesses/threading going on, and as you can see I have tried raising the timeout parameter). The sqlite file is stored on the local hard drive. The following function is one of many which accesses the sqlite database, and runs fine the first time it is called, but throws the above error the second time it is called (it is called as part of a for loop in another function): def update_index(filepath): path = get_setting('Local', 'web') stat = os.stat(filepath) modified = stat.st_mtime index_file = get_setting('Local', 'index') connection = sqlite3.connect(index_file, 30) cursor = connection.cursor() head, tail = os.path.split(filepath) cursor.execute('UPDATE hwlive SET date=? WHERE path=? AND name=?;', (modified, head, tail)) connection.commit() connection.close() Many thanks.

    Read the article

  • Round date to 10 minutes interval

    - by Peter Lang
    I have a DATE column that I want to round to the next-lower 10 minute interval in a query (see example below). I managed to do it by truncating the seconds and then subtracting the last digit of minutes. WITH test_data AS ( SELECT TO_DATE('2010-01-01 10:00:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:05:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:09:59', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:10:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2099-01-01 10:00:33', 'YYYY-MM-DD HH24:MI:SS') d FROM dual ) -- #end of test-data SELECT d, TRUNC(d, 'MI') - MOD(TO_CHAR(d, 'MI'), 10) / (24 * 60) FROM test_data And here is the result: 01.01.2010 10:00:00    01.01.2010 10:00:00 01.01.2010 10:05:00    01.01.2010 10:00:00 01.01.2010 10:09:59    01.01.2010 10:00:00 01.01.2010 10:10:00    01.01.2010 10:10:00 01.01.2099 10:00:33    01.01.2099 10:00:00 Works as expected, but is there a better way? EDIT: I was curious about performance, so I did the following test with 500.000 rows and (not really) random dates. I am going to add the results as comments to the provided solutions. DECLARE t TIMESTAMP := SYSTIMESTAMP; BEGIN FOR i IN ( WITH test_data AS ( SELECT SYSDATE + ROWNUM / 5000 d FROM dual CONNECT BY ROWNUM <= 500000 ) SELECT TRUNC(d, 'MI') - MOD(TO_CHAR(d, 'MI'), 10) / (24 * 60) FROM test_data ) LOOP NULL; END LOOP; dbms_output.put_line( SYSTIMESTAMP - t ); END; This approach took 03.24 s.

    Read the article

  • Amazon EC2 prices for Windows Instance?

    - by Abhishek Gupta
    Hello Guys , I want to ask from some Amazon cloud technology Experts , that is it profitable to deploy our web application on amazon cloud as compared to normal server? Currently there are micro,small, large and other types of instances available , if we start from micro instance then we realize that our app needs some more CPU cycle and Ram then how can we dynamically move to next more powerful instance automatically at runtime. What is the approx minimum yearly cost for a single EC2 windows small instance? I wnat to deploy a simple Online quiz application (ASP.net based) on Amazon Cloud which at a time can have maximum of 500 users only. Please suggest me as I m very new to Cloud .Should I go for Azure or Amazon?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 712 713 714 715 716 717 718 719 720 721 722 723  | Next Page >