Search Results

Search found 31931 results on 1278 pages for 'sql statement'.

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 624/1278 | < Previous Page | 620 621 622 623 624 625 626 627 628 629 630 631  | Next Page >

  • Which Database to choose?

    - by Sundar
    I have the following criteria Database should be protected with a username and password. It should not be possible to copy the database file and use it else were like MS Access. There will be no central database server. Each machine will run their own database server locally and user will initiate synchronization. Concept is inspired from distributed version control system like Git. So it should have good replication support. Strong consistency is not needed. Users will synchronize each other database when they need. In case of conflicts it should be possible to find the conflict and present it (from application) to the user for fixing it. Revisions of data if available it will be good. e.g. Entire history of change to a invoice. I explored document oriented database and inclined towards the same. But I dont know what to choose. Database is small it will not reach even 1GB in the next few years (say 3 years). Please feel free to suggest any database which you think might be suitable. Any pointers is highly appreciated. Thanks in advance.

    Read the article

  • Isn't INT more efficient than UNIQUEIDENTIFIER?

    - by ck
    I have a parent table and child table where the columns that join them together are the UNIQUEIDENTIFIER type. The child table has a clustered index on the column that joins it to the parent table (its PK, which is also clustered). I have created a copy of both of these tables but changed the relationship columns to be INTs instead, have rebuilt the indexes so that they are essentially the same structure and can be queried in the same way. When I query for a known 20 records from the parent table, pulling in all the related records from the child tables, I get identical query costs across both, i.e. 50/50 cost for the batches. If this is true, then my giant project to change all of the tables like this appears to be pointless, other than speeding up inserts. Can anyone provide any light on the situation?

    Read the article

  • How to ignore blank elements in linq query

    - by Maestro1024
    How to ignore blank elements in linq query I have a linq query var usersInDatabase = from user in licenseUserTable where user.FirstName == first_name && user.LastName == last_name select user; But if I get here and first_name or last_name is blank then I want to still evaluate the other data item.

    Read the article

  • How do You Get a Specific Value From a System.Data.DataTable Object?

    - by Giffyguy
    I'm a low-level algorithm programmer, and databases are not really my thing - so this'll be a n00b question if ever there was one. I'm running a simple SELECT query through our development team's DAO. The DAO returns a System.Data.DataTable object containing the results of the query. This is all working fine so far. The problem I have run into now: I need to pull a value out of one of the fields of the first row in the resulting DataTable - and I have no idea where to even start. Microsoft is so confusing about this! Arrrg! Any advice would be appreciated. I'm not providing any code samples, because I believe that context is unnecessary here. I'm assuming that all DataTable objects work the same way, no matter how you run your queries - and therefore any additional information would just make this more confusing for everyone.

    Read the article

  • 2 large databases - worth merging into 1?

    - by Ardman
    I have 2 large databases that were sharded before. I now have removed the sharding and have created a new database with all of the data except for the tables that were originally sharded. Is it worth importing this data into the new database, or keeping them as seperate entities that I can just scan through? We are talking around 60million records in each sharded table, of which there are 2 tables. Also, whilst I have an empty table, should I be adding indexes which weren't thought of when the database was originally constructed and now too large to add them?

    Read the article

  • tsql getdate conversion

    - by Manjot
    Hi, I know that when i do the following, it converts getdate to int select cast (getdate() as int) Getdate output on my server is "2010-06-11 14:42:20.100" and the int to which the above command is converting to is 40339. What is this integer? Did this int consider minutes and seconds? i am confused. Please help. Regards Manjot

    Read the article

  • Trigger Code on a table in my ERP Database

    - by David Stein
    My ERP Vendor has the following trigger on a table: SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TRIGGER [dbo].[SOItem_DeleteCheck] ON [dbo].[soitem] FOR DELETE AS BEGIN DECLARE @RecCnt int, @LogInfo varchar(256) SET @RecCnt = (SELECT COUNT(*) FROM deleted) IF @RecCnt > 150 BEGIN RAISERROR (54010, 18, 1, 'SOItem') WITH LOG ROLLBACK TRANSACTION END SET @LogInfo = 'Deleting ' + LTRIM(STR(@RecCnt)) + ' Rows From SOItem' EXEC LogDeletes @LogInfo END GO This seems very inefficient to me. Doesn't select count(*) take longer than Count(specific field)?

    Read the article

  • speed up a sql query to mysql?

    - by fayer
    in my mysql database i've got the geonames database, containing all countries, states and cities. i am using this to create a cascading menu so the user could select where he is from: country - state - county - city. but the main problem is that the query will search through all the 7 millions rows in that table each time i want to get the list of children rows, and that is taking a while 10-15 seconds. i wonder how i could speed this up: caching? table views? reorganizing table structure somehow? and most important, how do i do these things? are there good tutorials you could link to me? i appreciate all help and feedback discussing smart ways of handling this issue!

    Read the article

  • MYSQL TRIGGER LOOP

    - by Lee
    Hey all I am going through the pain stacking process of sorting out someone else code. So I am decided to recreate a new database to sit alongside the old one then to use triggers to transfer data between both tables. Now I have an issue with a it looping IE A trigger on each table to update the other. Once one updates it should update the other but as both tables have triggers it just will loop which will cause an issue. Is their a way to stop this from happening ? Hope this makes sense and hope you can advise.

    Read the article

  • performance issue in a select query from a single table

    - by daedlus
    Hi , I have a table as below dbo.UserLogs ------------------------------------- Id | UserId |Date | Name| P1 | Dirty ------------------------------------- There can be several records per userId[even in millions] I have clustered index on Date column and query this table very frequently in time ranges. The column 'Dirty' is non-nullable and can take either 0 or 1 only so I have no indexes on 'Dirty' I have several millions of records in this table and in one particular case in my application i need to query this table to get all UserId that have at least one record that is marked dirty. I tried this query - select distinct(UserId) from UserLogs where Dirty=1 I have 10 million records in total and this takes like 10min to run and i want this to run much faster than this. [i am able to query this table on date column in less than a minute.] Any comments/suggestion are welcome. my env 64bit,sybase15.0.3,Linux

    Read the article

  • Database with users design

    - by 1110
    I am in database design development phase. Application will work with large number of users (LARGE :)) I designed 80% of database but I have one Users table which is connected to everything else: Users {UserId, FirstName, LastName, Username, Password, PasswordQuestion, PasswordAnswer, Gender, RoleId, LastLoginDate etc etc} I saw asp.net membership database structure where Users and Membership are two tables. My questions are: Should I use one users table with all users data in it or more tables? If answer is 'more tables', what tables to use? Any advice on how to structure relation between those tables? This is sample relation that I have, and trying to improve. I don't understand why user and userChild are separated tables?

    Read the article

  • What is C# equivalent of PHP's mysql_fetch_array function?

    - by Mike Biff
    I am learning C#/ASP.NET and I am wondering what the C# equivalent of the following PHP code is? I know the userid, and I want to fetch the rows from this table into the array of the variable "row", so I then can use it as "row['name']" and "row['email']. $result = mysql_query("SELECT email, name FROM mytable WHERE id=7"); while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { printf("Email: %s Name: %s", $row["email"], $row["name"]); } Thanks.

    Read the article

  • Random Page Cost and Planning

    - by Dave Jarvis
    A query (see below) that extracts climate data from weather stations within a given radius of a city using the dates for which those weather stations actually have data. The query uses the table's only index, rather effectively: CREATE UNIQUE INDEX measurement_001_stc_idx ON climate.measurement_001 USING btree (station_id, taken, category_id); Reducing the server's configuration value for random_page_cost from 2.0 to 1.1 had a massive performance improvement for the given range (nearly an order of magnitude) because it suggested to PostgreSQL that it should use the index. While the results now return in 5 seconds (down from ~85 seconds), problematic lines remain. Bumping the query's end date by a single year causes a full table scan: sc.taken_start >= '1900-01-01'::date AND sc.taken_end <= '1997-12-31'::date AND How do I persuade PostgreSQL to use the indexes regardless of years between the two dates? (A full table scan against 43 million rows is probably not the best plan.) Find the EXPLAIN ANALYSE results below the query. Thank you! Query SELECT extract(YEAR FROM m.taken) AS year, avg(m.amount) AS amount FROM climate.city c, climate.station s, climate.station_category sc, climate.measurement m WHERE c.id = 5182 AND earth_distance( ll_to_earth(c.latitude_decimal,c.longitude_decimal), ll_to_earth(s.latitude_decimal,s.longitude_decimal)) / 1000 <= 30 AND s.elevation BETWEEN 0 AND 3000 AND s.applicable = TRUE AND sc.station_id = s.id AND sc.category_id = 1 AND sc.taken_start >= '1900-01-01'::date AND sc.taken_end <= '1996-12-31'::date AND m.station_id = s.id AND m.taken BETWEEN sc.taken_start AND sc.taken_end AND m.category_id = sc.category_id GROUP BY extract(YEAR FROM m.taken) ORDER BY extract(YEAR FROM m.taken) 1900 to 1996: Index "Sort (cost=1348597.71..1348598.21 rows=200 width=12) (actual time=2268.929..2268.935 rows=92 loops=1)" " Sort Key: (date_part('year'::text, (m.taken)::timestamp without time zone))" " Sort Method: quicksort Memory: 32kB" " -> HashAggregate (cost=1348586.56..1348590.06 rows=200 width=12) (actual time=2268.829..2268.886 rows=92 loops=1)" " -> Nested Loop (cost=0.00..1344864.01 rows=744510 width=12) (actual time=0.807..2084.206 rows=134893 loops=1)" " Join Filter: ((m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (sc.station_id = m.station_id))" " -> Nested Loop (cost=0.00..12755.07 rows=1220 width=18) (actual time=0.502..521.937 rows=23 loops=1)" " Join Filter: ((sec_to_gc(cube_distance((ll_to_earth((c.latitude_decimal)::double precision, (c.longitude_decimal)::double precision))::cube, (ll_to_earth((s.latitude_decimal)::double precision, (s.longitude_decimal)::double precision))::cube)) / 1000::double precision) <= 30::double precision)" " -> Index Scan using city_pkey1 on city c (cost=0.00..2.47 rows=1 width=16) (actual time=0.014..0.015 rows=1 loops=1)" " Index Cond: (id = 5182)" " -> Nested Loop (cost=0.00..9907.73 rows=3659 width=34) (actual time=0.014..28.937 rows=3458 loops=1)" " -> Seq Scan on station_category sc (cost=0.00..970.20 rows=3659 width=14) (actual time=0.008..10.947 rows=3458 loops=1)" " Filter: ((taken_start >= '1900-01-01'::date) AND (taken_end <= '1996-12-31'::date) AND (category_id = 1))" " -> Index Scan using station_pkey1 on station s (cost=0.00..2.43 rows=1 width=20) (actual time=0.004..0.004 rows=1 loops=3458)" " Index Cond: (s.id = sc.station_id)" " Filter: (s.applicable AND (s.elevation >= 0) AND (s.elevation <= 3000))" " -> Append (cost=0.00..1072.27 rows=947 width=18) (actual time=6.996..63.199 rows=5865 loops=23)" " -> Seq Scan on measurement m (cost=0.00..25.00 rows=6 width=22) (actual time=0.000..0.000 rows=0 loops=23)" " Filter: (m.category_id = 1)" " -> Bitmap Heap Scan on measurement_001 m (cost=20.79..1047.27 rows=941 width=18) (actual time=6.995..62.390 rows=5865 loops=23)" " Recheck Cond: ((m.station_id = sc.station_id) AND (m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (m.category_id = 1))" " -> Bitmap Index Scan on measurement_001_stc_idx (cost=0.00..20.55 rows=941 width=0) (actual time=5.775..5.775 rows=5865 loops=23)" " Index Cond: ((m.station_id = sc.station_id) AND (m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end) AND (m.category_id = 1))" "Total runtime: 2269.264 ms" 1900 to 1997: Full Table Scan "Sort (cost=1370192.26..1370192.76 rows=200 width=12) (actual time=86165.797..86165.809 rows=94 loops=1)" " Sort Key: (date_part('year'::text, (m.taken)::timestamp without time zone))" " Sort Method: quicksort Memory: 32kB" " -> HashAggregate (cost=1370181.12..1370184.62 rows=200 width=12) (actual time=86165.654..86165.736 rows=94 loops=1)" " -> Hash Join (cost=4293.60..1366355.81 rows=765061 width=12) (actual time=534.786..85920.007 rows=139721 loops=1)" " Hash Cond: (m.station_id = sc.station_id)" " Join Filter: ((m.taken >= sc.taken_start) AND (m.taken <= sc.taken_end))" " -> Append (cost=0.00..867005.80 rows=43670150 width=18) (actual time=0.009..79202.329 rows=43670079 loops=1)" " -> Seq Scan on measurement m (cost=0.00..25.00 rows=6 width=22) (actual time=0.001..0.001 rows=0 loops=1)" " Filter: (category_id = 1)" " -> Seq Scan on measurement_001 m (cost=0.00..866980.80 rows=43670144 width=18) (actual time=0.008..73312.008 rows=43670079 loops=1)" " Filter: (category_id = 1)" " -> Hash (cost=4277.93..4277.93 rows=1253 width=18) (actual time=534.704..534.704 rows=25 loops=1)" " -> Nested Loop (cost=847.87..4277.93 rows=1253 width=18) (actual time=415.837..534.682 rows=25 loops=1)" " Join Filter: ((sec_to_gc(cube_distance((ll_to_earth((c.latitude_decimal)::double precision, (c.longitude_decimal)::double precision))::cube, (ll_to_earth((s.latitude_decimal)::double precision, (s.longitude_decimal)::double precision))::cube)) / 1000::double precision) <= 30::double precision)" " -> Index Scan using city_pkey1 on city c (cost=0.00..2.47 rows=1 width=16) (actual time=0.012..0.014 rows=1 loops=1)" " Index Cond: (id = 5182)" " -> Hash Join (cost=847.87..1352.07 rows=3760 width=34) (actual time=6.427..35.107 rows=3552 loops=1)" " Hash Cond: (s.id = sc.station_id)" " -> Seq Scan on station s (cost=0.00..367.25 rows=7948 width=20) (actual time=0.004..23.529 rows=7949 loops=1)" " Filter: (applicable AND (elevation >= 0) AND (elevation <= 3000))" " -> Hash (cost=800.87..800.87 rows=3760 width=14) (actual time=6.416..6.416 rows=3552 loops=1)" " -> Bitmap Heap Scan on station_category sc (cost=430.29..800.87 rows=3760 width=14) (actual time=2.316..5.353 rows=3552 loops=1)" " Recheck Cond: (category_id = 1)" " Filter: ((taken_start >= '1900-01-01'::date) AND (taken_end <= '1997-12-31'::date))" " -> Bitmap Index Scan on station_category_station_category_idx (cost=0.00..429.35 rows=6376 width=0) (actual time=2.268..2.268 rows=6339 loops=1)" " Index Cond: (category_id = 1)" "Total runtime: 86165.936 ms"

    Read the article

  • Where is the future of databases?

    - by Danny
    I'm a bit frustrated with my MySQL database at the moment, so I've been thinking about all the things I'd like to see in the database of the future. But I thought it would be fun to hear other people's thoughts too--I'm not a pro by any means.

    Read the article

  • Normalization in plain English

    - by Yada
    I sort of understand the concept of database normalization but always have a hard time explaining it in plain English especially for a job interview. I have read the wikipedia post, but still find it hard to explain the concept to none developers. "Design a database in a way not to get duplicated data" is the first thing that comes to mind. Does anyone was a nice way to explain the concept of database normalization in plain English. And what are some nice examples to show the differences between first, second and third normal forms. Say you go to a job interview and the person asks: Explain the concept of normalization and how would go about designing a normalized database. What key points are the interviewer looking for?

    Read the article

  • view to select specific period or latest when null

    - by edosoft
    Hi I have a product table which simplifies to this: create table product(id int primary key identity, productid int, year int, quarter int, price money) and some sample data: insert into product select 11, 2010, 1, 1.11 insert into product select 11, 2010, 2, 2.11 insert into product select 11, 2010, 3, 3.11 insert into product select 12, 2010, 1, 1.12 insert into product select 12, 2010, 2, 2.12 insert into product select 13, 2010, 1, 1.13 Prices are can be changed each quarter, but not all products get a new price each quarter. Now I could duplicate the data each quarter, keeping the price the same, but I'd rather use a view. How can I create a view that can be used to return prices for (for example) quarter 2? I've written this to return the current (=latest) price: CREATE VIEW vwCurrentPrices AS SELECT * FROM ( SELECT *, ROW_NUMBER() OVER (PARTITION BY productid ORDER BY year DESC, quarter DESC) AS Ranking FROM product ) p WHERE p.Ranking = 1 I'd like to create a view so I can use queries like select * from vwProduct where quarter = 2

    Read the article

  • [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified - works

    - by Matt
    Hello, I am developing a java app (with odbc bridge - forgive me - the only paradox driver I have been able to obtain is the microsoft odbc driver) - which works fine while in eclipse, (and netbeans) - connecting and obtaining data from an ancient paradox 5.x database. So long as it is run from inside my IDE - it compiles and runs flawlessly. When I export it to a runable jar, suddenly [code][Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified[/code] occurs. The jar is being run on the same box as my developing IDE - so I am confused about the cause. It is being run via console from a user account, as per the IDE. My connection string is "jdbc:odbc:Driver={Microsoft Paradox Driver (*.db )};DriverID=538; Fil=Paradox 5.X; DefaultDir=C:\paradox\database\location\" - obtained from connectionstrings.com - and as mentioned before, working fine while run from the IDE. The above seems to 'magically' create its own connection, avoiding the setup of a dsn - I am unsure quite how it does - but it works. The only other thing I can think that might be pertinent is that my PC is a 64bit o/s (windows server 2008). Please help, any suggestions or comments will be greatly appreciated. Thanks, Matt

    Read the article

  • SqlCeResultSet re-use

    - by pdiddy
    Can I reuse an existing result set to filter? Lets say I have a result set that contains all data. Then I want to filter that resultset. Can I just execute the sqlcommand on the same resultset? I tried and it didn't seem to work. Does someone know the reason? So the only way to make it work was to create a new resultset and execute the command on that one. So this way I'm always creating a new resulset, can this have some issue?

    Read the article

  • Strategy Design Pattern -- *dynamic* !!!

    - by alexeypro
    My application will have different strategies for my objects. What's the best way of implementing that? I would really love the case when we can make strategy classes implementation dynamically loaded from, say, some relational database. Not sure how do that better, though. What's the best approach? Idea is that say we want to apply to object MyObj strategy Strategy123 then we just load from database by ID 123 the object, deserialize it, get the Strategy class, and use it with MyObj. The maintenance while sounds easier from the first look can be a pain in the long run if Strategy interfaces changes, etc. What can I do also? I want to find solution when I should be keeping Strategy classes in codebase -- just for the sake that I don't need code change and re-deployment of the application if my Strategy changes, or I add new strategy. Please advise!

    Read the article

  • Filter entities that match all pairs

    - by Jon
    I have an entity (let's say Person) with a set of arbitrary attributes with a known subset of values. I need to search for all of these entities that match all my filter conditions. For example, my table structures look like this: Person: id | name 1 | John Doe 2 | Jane Roe 3 | John Smith Attribute: id | attr_name 1 | Sex 2 | Eye Color ValidValue: id | attr_id | value_name 1 | 1 | Male 2 | 1 | Female 3 | 2 | Blue 4 | 2 | Green 5 | 2 | Brown PersonAttributes id | person_id | attr_id | value_id 1 | 1 | 1 | 1 2 | 1 | 2 | 3 3 | 2 | 1 | 2 4 | 2 | 2 | 4 5 | 3 | 1 | 1 6 | 3 | 2 | 4 In JPA, I have entities built for all of these tables. What I'd like to do is perform a search for all entities matching a given set of attribute-value pairs. For instance, I'd like to be able to find all males (John Doe and John Smith), all people with green eyes (Jane Roe or John Smith), or all females with green eyes (Jane Roe). I see that I can already take advantage of the fact that I only really need to match on value_id, since that's already unique and tied to the attr_id. But where can I go from there?

    Read the article

  • Newbie database index question

    - by RenderIn
    I have a table with multiple indexes, several of which duplicate the same columns: Index 1 columns: X, B, C, D Index 2 columns: Y, B, C, D Index 3 columns: Z, B, C, D I'm not very knowledgeable on indexing in practice, so I'm wondering if somebody can explain why X, Y and Z were paired with these same columns. B is an effective date. C is a semi-unique key ID for this table for a specific effective date B. D is a sequence that identifies the priority of this record for the identifier C. Why not just create 6 indexes, one for each X, Y, Z, B, C, D? I want to add an index to another column T, but in some contexts I'll only be querying on T alone while in others I will also be specifying the B, C and D columns... so should I create just one index like above or should I create one for T and one for (T, B, C, D)? I've not had as much luck as expected when googling for comprehensive coverage of indexing. Any resources where I can get a through explanation and lots of examples of B-tree indexing?

    Read the article

  • What is a columnar database?

    - by Raj More
    I have been working with warehousing for a while now. I am intrigued by Columnar Databases and the speed that they have to offer for data retrievals. I have multi-part question: How do Columnar Databases work? How do they differ from relational databases? Is there a trial version of a columnar database I can install to play around? (I am on Windows 7)

    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 | 620 621 622 623 624 625 626 627 628 629 630 631  | Next Page >