Search Results

Search found 36773 results on 1471 pages for 'sql statement syntax'.

Page 758/1471 | < Previous Page | 754 755 756 757 758 759 760 761 762 763 764 765  | Next Page >

  • R equivalent of SELECT DISTINCT on two or more fields/variables

    - by wahalulu
    Say I have a dataframe df with two or more columns, is there an easy way to use unique() or other R function to create a subset of unique combinations of two or more columns? I know I can use sqldf() and write an easy "SELECT DISTINCT var1, var2, ... varN" query, but I am looking for an R way of doing this. It occurred to me to try ftable coerced to a dataframe and use the field names, but I also get the cross tabulations of combinations that don't exist in the dataset: uniques <- as.data.frame(ftable(df$var1, df$var2))

    Read the article

  • need to read data from oracle database with many conditions

    - by randeepsp
    hi! i have 3 tables A,B and C. table A has column employee_name,id table B is the main table and has columns id,os version. table c has the columns id,package id and package version. i want to query the count of employee_name where the id of table a and c are matched with id of table b(which is the main table). i should also get the names of employees grouped by the os version they have and also the package version.

    Read the article

  • wanted to get all dates in mysql result

    - by PankajK
    I have mysql table called user(id, name, join_on) join on is a date field what I want is to show in each day how many uses has been created I can use group by but it will only give me the dates when users get added like if date 4/12/10 5 users added 4/13/10 2 users added 4/15/10 7 users added here date 4/14/10 is missing and I want listing of all dates in one month. I have one solution for it by creating another table only for adding date and that table will left join my users table on join_on and will give total result but I don't want to do that as for creating that I need to create and add entries in date table please suggest the different approach for doing so. Thank you.

    Read the article

  • How does linq decide between inner & outer joins

    - by user287795
    Hi Usually linq is using an left outer join for its queries but on some cases it decides to use inner join instead. I have a situation where that decision results in wrong results since the second table doesn't always have suitable records and that removes the records from the first table. I'm using a linqdatasource over a dbml where the relevant tables are identical but one holds historical records removed from the first. both have the same primary key. and I'm using a dataloadoption to load both tables at once with out round trips. Would you explain why linq decided to use an inner join here? Thanks

    Read the article

  • limiting mysql results by range of a specific key INCLUDING DUPLICATES

    - by aVC
    I have a query SELECT p.*, m.*, (SELECT COUNT(*) FROM newPhotoonAlert n WHERE n.userIDfor='$id' AND n.threadID=p.threadID and n.seen='0') AS unReadCount FROM posts p JOIN myMembers m ON m.id = p.user_id LEFT JOIN following f ON (p.user_id = f.user_id AND f.follower_id='$id' AND f.request='0' AND f.status='1') JOIN myMembers searcher ON searcher.id = '$id' WHERE ((f.follower_id = searcher.id) OR m.id='$id') AND p.flagged <'5' ORDER BY p.threadID DESC,p.positionID It brings result as expected but I want to add Another CLAUSE to limit the results. Say a sample (minimal shown) set of data looks like this with the above query. threadID postID positionID url 564 1254 2 a.com 564 1245 1 a1.com 541 1215 3 b1.com 541 1212 2 b2.com 541 1210 1 b3.com 523 745 1 c1.com 435 689 2 d2.com 435 688 1 a4.com 256 345 1 s3.com 164 316 1 f1.com . . I want to get ROWS corresponding to 2 DISTINCT threadIDs starting from MAX, but I want to include duplicates as well. Something like AND p.threadID IN (Select just Two of all threadIDs currently selected, but include duplicate rows) So my result should be threadID postID positionID url 564 1254 2 a.com 564 1245 1 a1.com 541 1215 3 b1.com 541 1212 2 b2.com 541 1210 1 b3.com

    Read the article

  • Copying Primary key to another field in Access.

    - by BashLover
    Hey, I'm struggling to copy the Primary Key to another field in Access. This is irrelevant , but clarifying on what I'm comparing. ... WHERE Tunniste=" & [Tarkiste] & "" Tunniste = Primary Key , Autonumber , ID (Generated by Access.) Tarkiste = This is the field I want to copy it to compare it. I'm open to suggestions, I've already try'ed with Form_Load, using the following code. Private Sub Form_Load() DoCmd.RunSQL "UPDATE Korut SET [Tarkiste]=('" & Tunniste & "');" End Sub But this copied the same key to all the entries in "Tarkiste" field. In simplicity I want 1:1 copy of field "Tunniste" to "Tarkiste" , whichever method it takes. Started from this question. File Picker Replaces All Rows With The Same Choice.

    Read the article

  • Most efficient way to Update with Linq2Sql

    - by pranay
    can I update my employee record as given in below function or i have to make query of employee collection first and than i update data public int updateEmployee(App3_EMPLOYEE employee) { DBContextDataContext db = new DBContextDataContext(); db.App3_EMPLOYEEs.Attach(employee); db.SubmitChanges(); return employee.PKEY; } or i have to do this public int updateEmployee(App3_EMPLOYEE employee) { DBContextDataContext db = new DBContextDataContext(); App3_EMPLOYEE emp = db.App3_EMPLOYEEs.Single(e => e.PKEY == employee.PKEY); db.App3_EMPLOYEEs.Attach(employee,emp); db.SubmitChanges(); return employee.PKEY; } But i dont want to use second option is there any efficient way to update data

    Read the article

  • how to select the records whose several fields' combination will equal to a specific value

    - by poiu2000
    Hi all, Assume I have the following style table, col1 col2 and col3 have same value scopes, I want to select the records when two of the 3 columns have a value combination such as ('ab' and 'bc'), in the following example, the first 3 records should be selected. Any good way to do this? I am using Sybase. | id | col1 | col2 | col3 | 1 ab bc null 2 null ab bc 3 ab ab bc 4 de ab xy Thanks.

    Read the article

  • Query to check the consistency of records

    - by orunner
    I have four tables TableA: id1 id2 id3 value TableB: id1 desc TableC: id2 desc TableD: id3 desc What I need to do is to check if all combinations of id1 id2 id3 from table B C and D exist in the TableA. In other words, table A should contain all possible combinations of id1 id2 and id3 which are stored in the other three tables.

    Read the article

  • copy an identity column into another table

    - by slake
    I have 2 tables that are related,both have identity columns for primary keys and i am using a vb form to insert data into them,My problem is that i cannot get the child table to get the primary key of the parent table and use this as its foreign key in my database. the data is inserted fine though no foreign key constraint is made.I am wondering if a trigger will do it and if so how. All my inserting of data is done in vb. The user wont insert any keys. all these are identity columns that are auto generated. If a trigger is my way out please illustrate with an example. If there is another way i can do this in VB itself then please advise and an example will be greatly appreciated Thanks in advance

    Read the article

  • Creating a multi-row "table" as part of a SELECT

    - by Chad Birch
    I'm not really sure how to describe my question (thus the awful title), but it's related to this recent question. The problem would be easily solved if there was some way for me to create a "table" with 4 rows as part of my SELECT (to use with NOT IN or MINUS). What I mean is, I can do this: SELECT 1, 2, 3, 4; And will receive one row from the database: | 1 | 2 | 3 | 4 | But is there any way to receive the following (without using UNION, I don't really want a query that's potentially thousands of lines long with a long list)? | 1 | | 2 | | 3 | | 4 |

    Read the article

  • removing comma from string array

    - by sarah
    Hi, I want to execute a query like select ID from "xyz_DB"."test" where user in ('a','b') so the corresponding code is like String s="("; for(String user:selUsers){ s+= " ' " + user + " ', "; } s+=")"; Select ID from test where userId in s; The following code is forming the value of s as ('a','b',) i want to remove the comma after the end of array how to do this ?

    Read the article

  • How to differentiate two tables

    - by Nemat
    I have two tables and I want to get all records from one table that are different from the records in second table. Eg.: if we have four records in the first table like A,B,C,D and three records in the second table thats A,B,C then the answer of query should be D. I have tried "EXCEPT" operator but it doesn't work fine. Kindly help me in writing correct query for the given problem.

    Read the article

  • Best way to get distinct values from large table

    - by derivation
    I have a db table with about 10 or so columns, two of which are month and year. The table has about 250k rows now, and we expect it to grow by about 100-150k records a month. A lot of queries involve the month and year column (ex, all records from march 2010), and so we frequently need to get the available month and year combinations (ie do we have records for april 2010?). A coworker thinks that we should have a separate table from our main one that only contains the months and years we have data for. We only add records to our main table once a month, so it would just be a small update on the end of our scripts to add the new entry to this second table. This second table would be queried whenever we need to find the available month/year entries on the first table. This solution feels kludgy to me and a violation of DRY. What do you think is the correct way of solving this problem? Is there a better way than having two tables?

    Read the article

  • Help with sql query

    - by user225269
    I have two tables: subject and student. I'm trying to count the number of subjects enrolled by each student. How do I do that?I'm trying the code below but it doesn't give the answer I need. Please help. SELECT COUNT( subject.SUBJECT ) , student.IDNO, student.FIRSTNAME, subject.SUBJECT FROM student, subject GROUP BY subject.SUBJECT LIMIT 0 , 30

    Read the article

  • Entity diagram with tables that have foreign keys that point to a non-PK column do not show relation

    - by Jason Coyne
    I have two tables parent and child. If I make a foreign key on child that points to the primary key of parent, and then make an entity diagram, the relationship is shown correctly. If I make the foreign key point to a different column, the relationship is not shown. I have tried adding indexes to the column, but it does not have an effect. The database is sqlite, but I am not sure if that has an effect since its all hidden behind ADO.net. How do I get the relationship to work correctly?

    Read the article

  • Problem with MySQL query

    - by Psyche
    This time my setup looks like this: one table with galleries names (gallery_id, gallery_name) and another table with galleries photos (photo_id, photo_gallery_id, photo_name). What I need is to get all the galleries with one random picture for each gallery. Is it possible to do this with a single query?

    Read the article

  • Firebird 2.1 + EXISTS = query bug?

    - by Atlas
    Using Delphi 2009 + Firebird 2.1.3. Database is ODS 11.1, default char set is UTF8. My prepared query is as follows: SELECT a.po_id, a.po_no FROM purchase_order a WHERE EXISTS (SELECT 1 FROM sales_order_item z1 JOIN purchase_order_item z2 ON z2.so_item_id = z1.so_item_id AND z2.po_id = a.po_id WHERE z1.so_id = :soid) ORDER BY a.po_no Now when I loop this say 1000 times because I have 1000 x so_id, the CPU usage get at 100% for FBSERVER.EXE Anyone encountered this problem?

    Read the article

  • Is an index required for columns in ON clause?

    - by newbie
    Do I have to create an index on columns referenced in Joins? E.g. SELECT * FROM left_table INNER JOIN right_table ON left_table.foo = right_table.bar WHERE ... Should I create indexes on left_table(foo), right_table(bar), or both? I noticed different results when I used EXPLAIN (Postgresql) with and without indexes and switching around the order of the comparison (right_table.bar = left_table.foo) I know for sure that indexes are used for the left of the WHERE clause but I am wondering whether I need indexes for columns listed in ON clauses.

    Read the article

  • Counting the instances of customers

    - by Mikae Combarado
    Say that I have a table with one column named CustomerId. The example of the instance of this table is : CustomerId 14 12 11 204 14 204 I want to write a query that counts the number of occurences of customer IDs. At the end, I would like to have a result like this : CustomerId NumberOfOccurences 14 2 12 1 11 1 204 2 14 1 I cannot think of a way to do this.

    Read the article

< Previous Page | 754 755 756 757 758 759 760 761 762 763 764 765  | Next Page >