Search Results

Search found 27337 results on 1094 pages for 'trv sql'.

Page 661/1094 | < Previous Page | 657 658 659 660 661 662 663 664 665 666 667 668  | Next Page >

  • Which index is used in select and why?

    - by Lukasz Lysik
    I have the table with zip codes with following columns: id - PRIMARY KEY code - NONCLUSTERED INDEX city When I execute query SELECT TOP 10 * FROM ZIPCodes I get the results sorted by id column. But when I change the query to: SELECT TOP 10 id FROM ZIPCodes I get the results sorted by code column. Again, when I change the query to: SELECT TOP 10 code FROM ZIPCodes I get the results sorted by code column again. And finally when I change to: SELECT TOP 10 id,code FROM ZIPCodes I get the results sorted by id column. My question is in the title of the question. I know which indexes are used in the queries, but my question is, why those indexes are used? I the second query (SELECT TOP 10 id FROM ZIPCodes) wouldn't it be faster if the clusteder index was used? How the query engine chooses which index to use?

    Read the article

  • Query with multiple IN-statements but without the cartesian product

    - by Janne
    How could I make this kind of query e.g. in MySQL SELECT * FROM Table t WHERE t.a IN (1,2,3) AND t.b IN (4,5,6) AND t.c IN (7,8,9) ... so that the result would contain only the three rows: t.a|t.b|t.c ---+---+--- 1 | 4 | 7 2 | 5 | 8 3 | 6 | 9 The above query of course returns all the combinations of the values in the IN clauses but I would like to get just the ones where the first elements of each tuple match, second elements of each tuple match and so on. Is there any efficient way to do this? By the way is there some common term for this kind of query or concept? I'm having hard time coming up with the question's title because I can't put this into words..

    Read the article

  • MySQL COUNT() total posts within a specific criteria?

    - by newbtophp
    Hey, I've been losing my hair trying to figure out what I'm doing wrong, let me explain abit about my MySQL structure (so you get a better understanding) before I go straight to the question. I have a simple PHP forum and I have a column in both tables (for posts and topics) named 'deleted' if it equals 0 that means its displayed (considered not deleted/exists) or if it equals 1 it hidden (considered deleted/doesn't exist) - bool/lean. Now, the 'specific criteria' I'm on about...I'm wanting to get a total post count within a specific forum using its id (forum_id), ensuring it only counts posts which are not deleted (deleted = 0) and their parent topics are not deleted either (deleted = 0). The column/table names are self explanatory (see my efforts below for them - if needed). I've tried the following (using a 'simple' JOIN): SELECT COUNT(t1.post_id) FROM forum_posts AS t1, forum_topics AS t2 WHERE t1.forum_id = '{$forum_id}' AND t1.deleted = 0 AND t1.topic_id = t2.topic_id AND t2.deleted = 0 LIMIT 1 I've also tried this (using a Subquery): SELECT COUNT(t1.post_id) FROM forum_posts AS t1 WHERE t1.forum_id = '{$forum_id}' AND t1.deleted = 0 AND (SELECT deleted FROM forum_topics WHERE topic_id = t1.topic_id) = 0 LIMIT 1 But both don't comply with the specific criteria. Appreciate all help! :)

    Read the article

  • SELECT table name that is inside UNION

    - by LexRema
    I have two same tables. I need to union them in such way: SELECT f1,f2, xxx FROM (SELECT * FROM tbl1 UNION ALL SELECT * FROM tbl2) where xxx would query for a table name, where f1 and f2 fields are taken from. Example output: 123 345 'tbl1' -- this rows are from the first table 121 345 'tbl1' 121 345 'tbl1' 123 345 'tbl1' 124 345 'tbl1' 125 345 'tbl2' -- this rows are from the second table 127 345 'tbl2' Thank you in advance.

    Read the article

  • my output parameters are always null when i use BeginExecuteNonQuery

    - by CharlesO
    I have a stored procedure that returns a varchar(160) as an output parameter of a stored procedure. Everything works fine when i use ExecuteNonQuery, i always get back the expected value. However, once i switch to use BeginExecuteNonQuery, i get a null value for the output. I am using connString + "Asynchronous Processing=true;" in both cases. Sadly the BeginExecuteNonQuery is about 1.5 times faster in my case...but i really need the output parameter. Thanks!

    Read the article

  • Oracle: how to "group by" over a range?

    - by Mark Harrison
    If I have a table like this: pkey age ---- --- 1 8 2 5 3 12 4 12 5 22 I can "group by" to get a count of each age. select age,count(*) n from tbl group by age; age n --- - 5 1 8 1 12 2 22 1 What query can I use to group by age ranges? age n ----- - 1-10 2 11-20 2 20+ 1

    Read the article

  • The best practice to setup hierarchy data

    - by eski
    I'm trying to figure out the best practice to setup hierarchy data that i take from a database into some contoller that would show the hierachy. Basicly this would look like a normal tree but when you press the items that are under "chapters" you get a link to another page. I have these tables and this is the way they are connected Period Courses Subjects Chapters I select Period from a DropDownBox and then i want all the courses in that period to line up. Under each course would be the subject and under them are the chapers, typical hierarchy. The tables are linked together with refrences to each other in linear way. I have tried to use treeview to show this, but dont understand how to do it. I though i could use <ul><il> tags and do it at runtime. Reapeter or datalist, possible ? Is it better to do this with databinding in XAML or in code ?

    Read the article

  • Solr autocommit and autooptimize?

    - by Camran
    I will be uploading my website to a VPS soon. It is a classifieds website which uses Solr integrated with MySql. Solr is updated whenever a new classified is put or deleted. I need a way to make the commit() and optimize() be automated, for example once every 3 hours or so. How can I do this? (Details Please) When is it ideal to optimize? Thanks

    Read the article

  • Filter on count(*) in oracle

    - by chris
    I have a grouped query, and would like to filter it based on count(*) Can I do this without a subquery? This is what I have currently: select * from (select ID, count(*) cnt from name group by ID) where cnt > 1;

    Read the article

  • How can i design a DB where the user can define the fields and types of a detail table in a M-D rela

    - by Simon
    My application has one table called 'events' and each event has approx 30 standard fields, but also user defined fields that could be any name or type, in an 'eventdata' table. Users can define these event data tables, by specifying x number of fields (either text/double/datetime/boolean) and the names of these fields. This 'eventdata' (table) can be different for each 'event'. My current approach is to create a lookup table for the definitions. So if i need to query all 'event' and 'eventdata' per record, i do so in a M-D relaitionship using two queries (i.e. select * from events, then for each record in 'events', select * from 'some table'). Is there a better approach to doing this? I have implemented this so far, but most of my queries require two distinct calls to the DB - i cannot simply join my master 'events' table with different 'eventdata' tables for each record in in 'events'. I guess my main question is: can i join my master table with different detail tables for each record? E.g. SELECT E.*, E.Tablename FROM events E LEFT JOIN 'E.tablename' T ON E._ID = T.ID If not, is there a better way to design my database considering i have no idea on how many user defined fields there may be and what type they will be.

    Read the article

  • Creating temporary tables in MySQL Stored Procedure

    - by burntblark
    The following procedure gives me an error when I invoke it using the CALL statement: CREATE DEFINER=`user`@`localhost` PROCEDURE `emp_performance`(id VARCHAR(10)) BEGIN DROP TABLE IF EXISTS performance; CREATE TABLE performance AS SELECT time_in, time_out, day FROM attendance WHERE employee_id = id; END The error says "Unknown table 'performance' ". This is my first time actually using stored procedures and I got my sources from Google. I just cant figure out what I am doing wrong.

    Read the article

  • Replace always replacing null values

    - by Mike
    Why does left(FIELD, replace(nullif(charindex('-', FIELD), 0), null, len(FIELD))) always return null? The idea behind the query is that if charindex() returns 0, then convert the results into null, then convert the null into the length of the field. So if '-' does not exist, show the whole string. For some reason it makes every row equal null. Thank you.

    Read the article

  • “Function” calling inside store procedure

    - by idimba
    Hi, I have a big store procedure, that contains a lot of INSERTs. There're many INSERTS that almost identical - they're different by some parameter(s) (all INSERTs to the same table) Is there a way to create a function/method, to which I'll pass the above parameter(s) and the function/method will generate concrete INSERT's? Thanks

    Read the article

  • How do I get every nth row in a table, or how do I break up a subset of a table into sets or rows of

    - by Jherico
    I have a table of heterogeneous pieces of data identified by a primary key (ID) and a type identifier (TYPE_ID). I would like to be able to perform a query that returns me a set of ranges for a given type broken into even page sizes. For instance, if there are 10,000 records of type '1' and I specify a page size of 1000, I want 10 pairs of numbers back representing values I can use in a BETWEEN clause in subsequent queries to query the DB 1000 records at a time. My initial attempt was something like this select id, rownum from CONTENT_TABLE where type_id = ? and mod(rownum, ?) = 0 But this doesn't work.

    Read the article

< Previous Page | 657 658 659 660 661 662 663 664 665 666 667 668  | Next Page >