Search Results

Search found 27519 results on 1101 pages for 'sql learner'.

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 657/1101 | < Previous Page | 653 654 655 656 657 658 659 660 661 662 663 664  | Next Page >

  • Which MySql line is faster:

    - by Camran
    I have a classified_id variable which matches one document in a MySql table. I am currently fetching the information about that one record like this: SELECT * FROM table WHERE table.classified_id = $classified_id I wonder if there is a faster approach, for example like this: SELECT 1 FROM table WHERE table.classified_id = $classified_id Wont the last one only select 1 record, which is exactly what I need, so that it doesn't have to scan the entire table but instead stops searching for records after 1 is found? Or am I dreaming this? Thanks

    Read the article

  • Query crashes MS Access

    - by user284651
    THE TASK: I am in the process of migrating a DB from MS Access to Maximizer. In order to do this I must take 64 tables in MS ACCESS and merge them into one. The output must be in the form of a TAB or CSV file. Which will then be imported into Maximizer. THE PROBLEM: Access is unable to perform a query that is so complex it seems, as it crashes any time I run the query. ALTERNATIVES: I have thought about a few alternatives, and would like to do the least time-consuming one, out of these, while also taking advantage of any opportunities to learn something new. Export each table into CSVs and import into SQLight and then make a query with it to do the same as what ACCESS fails to do (merge 64 tables). Export each table into CSVs and write a script to access each one and merge the CSVs into a single CSV. Somehow connect to the MS ACCESS DB (API), and write a script to pull data from each table and merge them into a CSV file. QUESTION: What do you recommend?

    Read the article

  • how to find end of quarter given a date in the quarter

    - by Ramy
    If i'm given a date (say @d = '11-25-2010'), how can I determine the end of the quarter from that date. I'd like to use a timestamp one second before midnight. I can get this: select dateadd(qq, datediff(qq, 0, getdate()), 0) as quarterStart which gives me: '10-1-2010' and I use this for one second before midnight of a given day: select DateAdd(second, -1, DateAdd(day, DateDiff(day, 0, @d))+1, 0) ) AS DayEnd in the end, a quarterEnd method would give me '12-31-2010 23:59:00'

    Read the article

  • Postgres: Find table foreign keys (Faster alternative)

    - by Najera
    Is there faster alternative to this: Take almost 1 minute in our server. SELECT tc.constraint_name, tc.table_name, kcu.column_name, ccu.table_name AS foreign_table_name, ccu.column_name AS foreign_column_name FROM information_schema.table_constraints AS tc JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name JOIN information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name WHERE constraint_type = 'FOREIGN KEY' AND tc.table_name='mytable'; Maybe using pg_class metadata?, thanks.

    Read the article

  • hibernate restrictions.in with and, how to use?

    - by cometta
    I have table like below id, employee_no, survey_no, name 1 test 1 test_name 2 test2 1 test_name2 3 test3 1 test_name3 4 test4 2 test_name4 how to query with Restriction.in by combining below AND into one IN statement? IN[ (if(survey_no==1) && employee_no== 'test') , (if(survey_no==1) && employee_no== 'test2') , ... ]

    Read the article

  • FOSS version of SQLCompare or something similar?

    - by Scott
    Actually, free is good enough, it doesn't have to be open source :) I'm currently using the Schema Compare utility of VS2008, but it doesn't have a command line interface and has some other weaknesses as well. I'm wondering what free tools others are using to provide command line schema comparisons/synchronizations? Thanks.

    Read the article

  • Concurrent usage of table causing issues

    - by Sven
    Hello In our current project we are interfacing with a third party data provider. They need to insert data in a table of ours. This inserting can be frequent every 1 min, every 5min, every 30, depends on the amount of new data they need to provide. The use the isolation level read committed. On our end we have an application, windows service, that calls a webservice every 2 minutes to see if there is new data in this table. Our isolation level is repeatable read. We retrieve the records and update a column on these rows. Now the problem is that sometimes this third party provider needs to insert a lot of data, let's say 5000 records. They do this per transaction (5rows per transaction), but they don't close the connection. They do one transaction and then the next untill all records are inserted. This caused issues for our process, we receive a timeout. If this goes on for a long time the database get's completely unstable. For instance, they maybe stopped, but the table somehow still stays unavailable. When I try to do a select on the table, I get several records but at a certain moment I don't get any response anymore. It just says retrieving data but nothing comes anymore until I get a timeout exception. Only solution is to restart the database and then I see the other records. How can we solve this. What is the ideal isolation level setting in this scenario?

    Read the article

  • error in fill datagrid whit query

    - by Amir Tavakoli
    i have a data-gride-view and i add my query to this when write my query i catch this error: The schema returned by the new query differs from the base query and this my query: SELECT B.SettingKey, 'SysSettingsDep' AS TableName, B.SettingValue, B.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettingsDep AS B ON A.SettingKey = B.SettingKey UNION SELECT C.SettingKey, 'SysSettingsMachine' AS TableName, C.SettingValue, C.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettingsMachine AS C ON A.SettingKey = C.SettingKey UNION SELECT D.SettingKey, 'SysSettings' AS TableName, D.SettingValue, D.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettings AS D ON A.SettingKey = D.SettingKey help me to solve this, tnx

    Read the article

  • Count total number of callers?

    - by Kristopher Ives
    I'm currently doing this query to find the guy who makes the most calls: SELECT `commenter_name`, COUNT(*) AS `calls` FROM `comments` GROUP BY `commenter_name` ORDER BY `calls` LIMIT 1 What I want now is to be able to find out how many total unique callers. I tried using DISTINCT but I didn't get anywhere.

    Read the article

  • Clustered index on frequently changing reference table of one or more foreign keys

    - by Ian
    My specific concern is related to the performance of a clustered index on a reference table that has many rapid inserts and deletes. Table 1 "Collection" collection_pk int (among other fields) Table 2 "Item" item_pk int (among other fields) Reference Table "Collection_Items" collection_pk int, item_pk int (combined primary key) Because the primary key is composed of both pks, a clustered index is created and the data physically ordered in the table according to the combined keys. I have many users creating and deleting collections and adding and removing items to those collections very frequently affecting the "Collection_Items" table, and its clustered index. QUESTION PART: Since the "Collection_Items" table is so dynamic, wouldn't there be a big performance hit on constantly resorting the table rows because of the clustered index ? If yes, what should I do to minimize this ?

    Read the article

  • Performing Inner Join for Multiple Columns in the Same Table

    - by frankiefrank
    I have a scenario which I'm a bit stuck on. Let's say I have a survey about colors, and I have one table for the color data, and another for people's answers. tbColors color_code , color_name 1 , 'blue' 2 , 'green' 3 , 'yellow' 4 , 'red' tbAnswers answer_id , favorite_color , least_favorite_color , color_im_allergic_to 1 , 1 , 2 3 2 , 3 , 1 4 3 , 1 , 1 2 4 , 2 , 3 4 For display I want to write a SELECT that presents the answers table but using the color_name column from tbColors. I understand the "most stupid" way to do it naming tbColors three times in the FROM section, using a different alias for each column to replace. How would a non-stupid way look?

    Read the article

  • Embedded Java Databases for Large Data Sets

    - by ExAmerican
    I would like to port a PHP/MySQL-based client/server application to be a standalone desktop application written in Java. The database has grown to be fairly large, with several tables with hundreds of thousands of rows. I expect these could grow to over a million entries for certain tables. What embedded database would best handle this? HSQLDB and Sqlite seem to be the obvious choices, though I'm guessing there are others out there as well. My main priorities are the ability to perform queries on large amounts of data efficiently (this thread seems to confirm Sqlite can handle this) and the ease with which I can import old data from MySQL (I remember HSQLDB being kind of a pain for that). Note: I am aware that similar questions comparing embedded databases have been posted before (for example here and here) but as my priorities differ somewhat from most applications considering the large data migration I thought it justified a new question.

    Read the article

  • Optimize SQL query (Facebook-like application)

    - by fabriciols
    My application is similar to Facebook, and I'm trying to optimize the query that get user records. The user records are that he as src ou dst. The src is in usermuralentry directly, the dst list are in usermuralentry_user. So, a entry can have one src and many dst. I have those tables: mysql> desc usermuralentry ; +-----------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+------------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | user_src_id | int(11) | NO | MUL | NULL | | | private | tinyint(1) | NO | | NULL | | | content | longtext | NO | | NULL | | | date | datetime | NO | | NULL | | | last_update | datetime | NO | | NULL | | +-----------------+------------------+------+-----+---------+----------------+ 10 rows in set (0.10 sec) mysql> desc usermuralentry_user ; +-------------------+---------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------------+---------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | usermuralentry_id | int(11) | NO | MUL | NULL | | | userinfo_id | int(11) | NO | MUL | NULL | | +-------------------+---------+------+-----+---------+----------------+ 3 rows in set (0.00 sec) And the following query to retrieve information from two users. mysql> explain SELECT * FROM usermuralentry AS a , usermuralentry_user AS b WHERE a.user_src_id IN ( 1, 2 ) OR ( a.id = b.usermuralentry_id AND b.userinfo_id IN ( 1, 2 ) ); +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ | 1 | SIMPLE | b | ALL | usermuralentry_id,usermuralentry_user_bcd7114e,usermuralentry_user_6b192ca7 | NULL | NULL | NULL | 147188 | | | 1 | SIMPLE | a | ALL | PRIMARY | NULL | NULL | NULL | 1371289 | Range checked for each record (index map: 0x1) | +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ 2 rows in set (0.00 sec) but it is taking A LOT of time... Some tips to optimize? Can the table schema be better in my application?

    Read the article

  • History tables pros, cons and gotchas - using triggers, sproc or at application level.

    - by Nathan W
    I am currently playing around with the idea of having history tables for some of my tables in my database. Basically I have the main table and a copy of that table with a modified date and an action column to store what action was preformed eg Update,Delete and Insert. So far I can think of three different places that you can do the history table work. Triggers on the main table for update, insert and delete. (Database) Stored procedures. (Database) Application layer. (Application) My main question is, what are the pros, cons and gotchas of doing the work in each of these layers. One advantage I can think of by using the triggers way is that integrity is always maintained no matter what program is implmentated on top of the database.

    Read the article

  • Finding the count of characters and numbers in a string

    - by Aspirant
    Hi I have a table test as below NAME --------- abc1234 XYZ12789 a12X8b78Y9c5Z I try to find out the count of number of numbers and characters in the string as select name,length(replace(translate(lower(name),'abcdefghijklmnopqrstuvwxyz',' '),' ','')) as char_count, length(replace(translate(name,'1234567890',' '),' ','')) as num_count from test6; Its executing fine giving the output NAME CHAR_COUNT NUM_COUNT abc1234 4 3 XYZ12789 5 3 a12X8b78Y9c5Z 7 6 But my question is there any option by not giving the abcdefghijklmnopqrstuvwxyz and 1234567890 manually

    Read the article

  • Monitoring Log Shipped Databases

    - by Registered User
    I need a consistent way to monitor databases that are read-only log shipped copies of production databases. In the past I have relied on the following methods: Set the job that restores logs to the database kick off another job as its last step. Set the job that restores logs to the database to insert a record in a control table as its last step. Query the msdb database to check the status of the job that restores logs to the database. Query a control table inside the database itself that gets a value immediately before transaction logs are backed up. Query MAX values from tables inside the database to see if it has recent changes. Although the above methods work, they can't be implemented for every log shipped database that I query for various reasons. What is the best method for monitoring the "data as of" date for a log shipped database?

    Read the article

  • Help me choose between XML or SQL Lite on android

    - by Ngetha
    I have an android app that periodically, say once a week downloads content from a server in XML. The content is used by the app, different Acitivities use different parts of the content. My question is a design one, should I save the data in SQlite or just keep it as an XML file, which one would be faster to read? The app can only use one content piece at a time, which means subsequent XML content downloads replace the old one.

    Read the article

  • Best way to store a database password in a startup script / config file?

    - by Mark Harrison
    So our web server apps need to connect to the database, and some other apps have startup scripts that execute at boot time. What's the best way to store the name/password for these applications, in terms of security, e.g. perhaps we don't want sysadmins to know the database password maintainability, e.g. making the configuration easy to change when the password changes, etc. both windows and linux solutions appreciated!

    Read the article

  • create tree/XML structure from SQL query c#

    - by Tim Bassett
    Here is my current issue. I need to display a tree like structure displaying a recall roster. Our DBA created a stored procedure that returns [level],[name],[contact_info]. Example looks like: [1] [test name1] [contact info] [2] [sub to1] [contact info] [3] [sub to2] [contact info] [4] [sub to3] [contact info] [3] [sub to2] [contact info] [2] [sub to1] [contact info] etc... It's sorted in the order of the hierarchy I haven't really worked with XML much but is that the way to go in loading/presenting this data. Currently when I retrieving the data I'm returning it in a datatable. There may also be a need to export this data to Excel. Can anyone point me a good direction to go with this?

    Read the article

  • running a stored procedure inside a sql trigger

    - by Ying
    Hi all, the business logic in my application requires me to insert a row in table X when a row is inserted in table Y. Furthermore, it should only do it between specific times(which I have to query another table for). I have considered running a script every 5 minutes or so to check this, but I stumbled upon triggers and figured this might be a better way to do it. But I find the syntax for procedures a little bewildering and I keep getting an error I have no idea how to fix. Here is where I start: CREATE TRIGGER reservation_auto_reply AFTER INSERT ON reservation FOR EACH ROW BEGIN IF NEW.sent_type = 1 /* In-App */ THEN INSERT INTO `messagehistory` (`trip`, `fk`, `sent_time`, `status`, `message_type`, `message`) VALUES (NEW.trip, NEW.psk, 'NOW()', 'submitted', 4, 'This is an automated reply to reservation'); END; I get an error in the VALUES part of the statmenet but im not sure where. I still have to query the other table for the information I need, but I can't even get past this part. Any help is appreciated, including links to many examples..Thanks

    Read the article

  • Help converting subquery to query with joins

    - by Tim
    I'm stuck on a query with a join. The client's site is running mysql4, so a subquery isn't an option. My attempts to rewrite using a join aren't going too well. I need to select all of the contractors listed in the contractors table who are not in the contractors2label table with a given label ID & county ID. Yet, they might be listed in contractors2label with other label and county IDs. Table: contractors cID (primary, autonumber) company (varchar) ...etc... Table: contractors2label cID labelID countyID psID This query with a subquery works: SELECT company, contractors.cID FROM contractors WHERE contractors.complete = 1 AND contractors.archived = 0 AND contractors.cID NOT IN ( SELECT contractors2label.cID FROM contractors2label WHERE labelID <> 1 AND countyID <> 1 ) I thought this query with a join would be the equivalent, but it returns no results. A manual scan of the data shows I should get 34 rows, which is what the subquery above returns. SELECT company, contractors.cID FROM contractors LEFT OUTER JOIN contractors2label ON contractors.cID = contractors2label.cID WHERE contractors.complete = 1 AND contractors.archived = 0 AND contractors2label.labelID <> 1 AND contractors2label.countyID <> 1 AND contractors2label.cID IS NULL

    Read the article

  • How to check if a child-object is populated

    - by TheQ
    How can i check if a child-object of a linq-object is populated or not? Example code below. My model have two methods, one joins data, and the other does not: public static Member GetMemberWithPhoto(Guid memberId) { using (DataContext db = new DataContext()) { DataLoadOptions dataLoadOptions = new DataLoadOptions(); dataLoadOptions.LoadWith<Member>(x => x.UserPhoto); db.LoadOptions = dataLoadOptions; var query = from x in db.Members where x.MemberId == memberId select x; return query.FirstOrDefault(); } } public static Member GetMember(Guid memberId) { using (DataContext db = new DataContext()) { var query = from x in db.Members where x.MemberId == memberId select x; return query.FirstOrDefault(); } } Then my control have the following code: Member member1 = Member.GetMemberWithPhoto(memberId); Member member2 = Member.GetMember(memberId); Debug.WriteLine(member1.UserPhoto.ToString()); Debug.WriteLine(member2.UserPhoto.ToString()); The last line will generate a "Cannot access a disposed object" exception. I know that i can get rid of that exception just by not disposing the datacontext, but then the last line will generate a new query to the database, and i don't want that. What i would like is something like: Debug.WriteLine((member1.UserPhoto.IsPopulated()) ? member1.UserPhoto.ToString() : "none"); Debug.WriteLine((member2.UserPhoto.IsPopulated()) ? member2.UserPhoto.ToString() : "none"); Is it possible?

    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 | 653 654 655 656 657 658 659 660 661 662 663 664  | Next Page >