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 648/1101 | < Previous Page | 644 645 646 647 648 649 650 651 652 653 654 655  | Next Page >

  • Collection was modified; enumeration operation may not execute

    - by Rita
    I have the below code. I am trying to remove the record and it is throwing Exception when it is removing the Record. "Collection was modified; enumeration operation may not execute." Any ideas on how to get rid of the message. Appreciate your time. //validClaimControlNo has valid ClaimControl Numbers. List<string> validClaimControlNo = new List<string>(); int count = 0; foreach (List<Field> f in records) { foreach (Field fe in f) { if (i == 0) if (!(validClaimControlNo.Contains(fe.Value))) { //if this claim is not in the Valid list, Remove that Record records.RemoveAt(count); } i++; } i = 0; count++; }

    Read the article

  • Does MySQL allow two primary keys on one table?

    - by Bharanikumar
    CREATE TABLE Orders -> ( -> ID SMALLINT UNSIGNED NOT NULL, -> ModelID SMALLINT UNSIGNED NOT NULL, -> Descrip VARCHAR(40), -> PRIMARY KEY (ID, ModelID) -> ); Basically, this appears to me to be creating two primary key on one table. Is that correct? I thought that we could create a number of unique keys in one table, but only one primary key. How is it that my system is allowing the creation of multiple primary keys? Please advise: what are the rules governing this?

    Read the article

  • Caching stored procedure results in Linq'u

    - by itdebeloper
    In our web application we have a lots of stored procedures look like this one: getSomeData(/* 7 diffrent params */) This stored procedure don't make any updates. We are using Linq'u. I know that the date are changing no often than once per day so the results for the same sets of parameters values will be the same. Does Linqu have cache simple solution? I know how to 'manually' write cache mechanism in .net, but I supposed that in Linqu this problem was solved. I'm a lazy guy :) so I'm looking for something realy simple like: Linqu_global_store_procedure_configuration.CacheDuration="600" Linqu_global_store_procedure_configuration.CacheVaryByParam="*" I'm using .net 3.5 but its not any problem to move for 4.0.

    Read the article

  • Can I concatenate multiple MySQL rows into one field?

    - by Dean
    Using MySQL, I can do something like select hobbies from peoples_hobbies where person_id = 5; and get: shopping fishing coding but instead I just want 1 row, 1 col: shopping, fishing, coding The reason is that I'm selecting multiple values from multiple tables, and after all the joins I've got a lot more rows than I'd like. I've looked for a function on MySQL Doc and it doesn't look like the CONCAT or CONCAT_WS functions accept result sets, so does anyone here know how to do this?

    Read the article

  • Multiple user database design

    - by dieguitoweb
    I have to develop a basic social network for an academic purpose; but I need some tips for the users management.. The users are subdivided into 3 groups with different privilege: admins,analysts and standards users. For every user should be stored into the database the following information: name,lastname,e-mail,age,password. I'm not quite sure how I should design the database between theese two solutions: 1)one table called 'users' with the 'role' attribute that explain what a user can do and what can't do, and the permissions are managed via php 2)every application user is a database user created with the query 'CREATE ROLE' (It's a postgres database) and he has permissions on some tables granted with the 'GRANT' statement You should take into account that the project is for a database exam.. thanks

    Read the article

  • How can I improve the below query?

    - by Newbie
    I have the following input. INPUT: TableA ID Sentences --- ---------- 1 I am a student 2 Have a nice time guys! What I need to do is to extract the words from the sentence(s) and insert each individual word in another table OUTPUT: SentenceID WordOccurance Word ---------- ------------ ----- 1 1 I 1 2 am 1 3 a 1 4 student 2 1 Have 2 2 a 2 3 nice 2 4 time 2 5 guys! I was able to get the answer by using the below query ;With numCTE As ( Select rn = 1 Union all Select rn+1 from numCTE where rn<1000) select SentenceID=id, WordOccurance=row_number()over(partition by TableA.ID order by rn), Word = substring(' '+sentences+' ', rn+1, charindex(' ',' '+sentences+' ', rn+1)-rn-1) from TableA join numCTE on rn <= len(' '+sentences+' ') where substring(' '+sentences+' ', rn,1) = ' ' order by id, rn How can I improve this query of mine.? Basically I am looking for a better solution than the one presented Thanks

    Read the article

  • Mysql query help needed

    - by Me-and-Coding
    Hi, i have two tables category and hotels where category.id should be equal to hotels.catid. Now how do i select 3 rows from each different category from the hotels table. I have this query: select h.* from hotels h inner join category c on h.catid = c.id order by h.catid, h.hid this selects all records, but i want to select three rows per different category so in all it should return 9 rows with 3 rows for each category. If this can not be done in mysql, you could also suggest php code please. Thanks

    Read the article

  • asp:QueryStringParameter and empty query string parameter

    - by abatishchev
    I haveasp:GridView displaying client requests using asp:SqlDataSource. I want to limit displayed information by client: View.aspx has to display everything, View.aspx?client=1 has to display only requests from client ID #1. So I'm using <asp:QueryStringParameter Name="client" QueryStringField="client" /> for query "EXEC getRequests @client". Everything works properly when some client is specified. But don't - if not. I tested my SP using SSMS - it works properly in both cases - when parameter is specified and when it isn't (NULL passed explicitly). What have I do?

    Read the article

  • Password security; Is this safe?

    - by Camran
    I asked a question yesterday about password safety... I am new at security... I am using a mysql db, and need to store users passwords there. I have been told in answers that hashing and THEN saving the HASHED value of the password is the correct way of doing this. So basically I want to verify with you guys this is correct now. It is a classifieds website, and for each classified the user puts, he has to enter a password so that he/she can remove the classified using that password later on (when product is sold for example). In a file called "put_ad.php" I use the $_POST method to fetch the pass from a form. Then I hash it and put it into a mysql table. Then whenever the users wants to delete the ad, I check the entered password by hashing it and comparing the hashed value of the entered passw against the hashed value in the mysql db, right? BUT, what if I as an admin want to delete a classified, is there a method to "Unhash" the password easily? sha1 is used currently btw. some code is very much appreciated. Thanks

    Read the article

  • Group by query design help

    - by Midhat
    Consider this data PK field1 field2 1 a b 2 a (null) 3 x y 4 x z 5 q w I need to get this data select all columns from all rows where field1 has count 1 i tried and finally settled for select * from mytable where field1 in (select field1 from mytable group by field1 having count(field1)>1 ) order by field1 but there has to be a better way than this

    Read the article

  • How to check if an entityset is populated

    - by TheQ
    How can i check if an entityset 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 GetMemberWithSettings(Guid memberId) { using (DataContext db = new DataContext()) { DataLoadOptions dataLoadOptions = new DataLoadOptions(); dataLoadOptions.LoadWith<Member>(x => x.Settings); 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.GetMemberWithSettings(memberId); Member member2 = Member.GetMember(memberId); Debug.WriteLine(member1.Settings.Count); Debug.WriteLine(member2.Settings.Count); 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.Settings.IsPopulated()) ? member1.Settings.Count : -1); Debug.WriteLine((member2.Settings.IsPopulated()) ? member2.Settings.Count : -1); Is it possible?

    Read the article

  • best database design for city zip & state tables

    - by ryan a
    My application will need to reference addresses. Street info will be stored with my main objects but the rest needs to be stored seperately to reduce redundancy. How should I store/retrieve ZIPs, cities and states? Here are some of my ideas. single table solution (cant do relationships) [locations] locationID locationParent (FK for locationID - 0 for state entries) locationName (city, state) locationZIP two tables (with relationships, FK constraints, ref integrity) [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName zipCode three tables [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName [zip] zipID cityID (FK for city.cityID) zipName Then I read into ZIP codes amd how they are assigned. They aren't specifically related to cities. Some cities have more than one ZIP (ok will still work) but some ZIPs are in more than one city (oh snap) and some other ZIPs (very few) are in more than one state! Also some ZIPs are not even in the same state as the address they belong to at all. Seems ZIPs are made for carrier route identification and some remote places are best served by post offices in neighboring cities or states. Does anybody know of a good (not perfect) solution that takes this into consideration to minimize discrepencies as the database grows?

    Read the article

  • How do I use on delete cascade in mysql?

    - by Marius
    I have a database of components. Each component is of a specific type. That means there is a many-to-one relationship between a component and a type. When I delete a type, I would like to delete all the components which has a foreign key of that type. But if I'm not mistaken, cascade delete will delete the type when the component is deleted. Is there any way to do what I described?

    Read the article

  • mysql reference result from subquery

    - by iamrohitbanga
    this is what i am doing update t1 set x=a,y=b where a and b are obtained from (select query here) i know the select query the select query returns multiple results which are the same when i use group by or distinct query execution slows down considerably a and b are forward references so mysql reports an error i want to set a equal to the value obtained in the first row and b equal to the value obtained in the first row for the respective columns, to avoid group by. i don't know how to refer to the first result from the select query. how can i achieve all this?

    Read the article

  • How can I count existing and non-existing values with MySQL?

    - by jaya malladi
    I am new to MySQL. I have a table with answer ids. Answers can look like this:a1, a2, a3 ..., but due to some problems some are NULL, some are blank, and some are others like 1 a etc. Now I want to calculate the count of ids with a1 a2 a3 distinctly. But how is it possible to do this leaving others like NULL, blanks and garbage. The output should look like this atype count a1 45 a2 0 a3 56 If there is no row entry for a particular answer, the count should be 0.

    Read the article

  • Access is re-writing - and breaking - my query!

    - by FrustratedWithFormsDesigner
    I have a query in MS Access (2003) that makes use of a subquery. The subquery part looks like this: ...FROM (SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123") AS q1,... And when I switch to Table View to verify the results, all is OK. Then, I wanted the result of this query to be printed on the page header for a report (the query returns a single row that is page-header stuff). I get an error because the query is suddenly re-written as: ...FROM [SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123"; ] AS q1,... So it's Ok that the round brackets are automatically replaced by square brackets, Access feels it needs to do that, fine! But why is it adding the ; into the subquery, which causes it to fail? I suppose I could just create new query objects for these subqueries, but it seems a little silly that I should have to do that.

    Read the article

  • postgres subquery w/ derived column

    - by Wells
    The following query won't work, but it should be clear what I'm trying to do: split the value of 't' on space and use the last element in that array in the subquery (as it will match tl). Any ideas how to do this? Thanks! SELECT t, y, "type", regexp_split_to_array(t, ' ') as t_array, sum(dr), ( select uz from f.tfa where tl = t_array[-1] ) as uz, sc FROM padres.yd_fld WHERE y = 2010 AND pos <> 0 GROUP BY t, y, "type", sc;

    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 | 644 645 646 647 648 649 650 651 652 653 654 655  | Next Page >