Search Results

Search found 4815 results on 193 pages for 'parameterized queries'.

Page 125/193 | < Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >

• How to efficiently handle Where and OrderBy clauses

  - by Goran

  My business layer passes all the required information to UI layer. From what I have read, in general, best practice is to send fetched data to UI layer, and to avoid passing queries like ObjectQuery. My problem with this approach is next: If I am to make a flexible business layer, then I should allow UI to sort the data anyway it requires. Fetching sorted data from database, and then resorting them in UI is kind of bad practice for me, so the only way is to somehow So what are my options? Is there a way to make it like this: public void OrderByMethod(params ...) { .... } so I can call it like this: OrderByMethod(MyEntity.Property1, MyEntity.Property2 descending....); Thanks, Goran

  Read the article

• Writing my own iostream utility class: Is this a good idea?

  - by Alex

  I have an application that wants to read word by word, delimited by whitespace, from a file. I am using code along these lines: std::istream in; string word; while (in.good()) { in>>word; // Processing, etc. ... } My issue is that the processing on the words themselves is actually rather light. The major time consumer is a set of mySQL queries I run. What I was thinking is writing a buffered class that reads something like a kilobyte from the file, initializes a stringstream as a buffer, and performs extraction from that transparently to avoid a great many IO operations. Thoughts and advice?

  Read the article

• Android: making a custom ListView independent of adapters ?

  - by wei

  I am adding a local database as a cache to a remote web service in my android application to answer queries. I used ArrayAdapters before for list views to display the results from the web service. Now with a database cache, the result could be either a Cursor(from database) or a List(from web), which means the adapter can be CursorAdapter or ArrayAdapter too. Creating two adapters for one query doesn't seem to be a good idea. So I am wondering what would be the best way to refactor my current code to add this database feature? Thanks,

  Read the article

• Which SQL query is faster? Filter on Join criteria or Where clause?

  - by Jon Erickson

  Compare these 2 queries. Is it faster to put the filter on the join criteria or in the were clause. I have always felt that it is faster on the join criteria because it reduces the result set at the soonest possible moment, but I don't know for sure. I'm going to build some tests to see, but I also wanted to get opinions on which would is clearer to read as well. Query 1 SELECT * FROM TableA a INNER JOIN TableXRef x ON a.ID = x.TableAID INNER JOIN TableB b ON x.TableBID = b.ID WHERE a.ID = 1 /* <-- Filter here? */ Query 2 SELECT * FROM TableA a INNER JOIN TableXRef x ON a.ID = x.TableAID AND a.ID = 1 /* <-- Or filter here? */ INNER JOIN TableB b ON x.TableBID = b.ID

  Read the article

• Connection to DB2 in Python

  - by Mestika

  Hi, I'm trying to create a database connection in a python script to my DB2 database. When the connection is done I've to run some different SQL statements. I googled the problem and has read the ibm_db API (http://code.google.com/p/ibm-db/wiki/APIs) but just can't seem to get it right. Here is what I got so far: import sys import getopt import timeit import multiprocessing import random import os import re import ibm_db import time from string import maketrans query_str = None conn = ibm_db.pconnect("dsn=write","usrname","secret") query_stmt = ibm_db.prepare(conn, query_str) ibm_db.execute(query_stmt, "SELECT COUNT(*) FROM accounts") result = ibm_db.fetch_assoc() print result status = ibm_db.close(conn) but I get an error. I really tried everything (or, not everything but pretty damn close) and I can't get it to work. I just need to make a automatic test python script that can test different queries with different indexes and so on and for that I need to create and remove indexes a long the way. Hope someone has a solutions or maybe knows about some example codes out there I can download and study. Thanks Mestika

  Read the article

• mysql: select ... where id = any value. is it possible?

  - by Syom

  look at this table please table |id| |name| |order| i must get the rows, where name = something and order = somevalue so i write select `id` from `table` where `name` = 'something' and `order` = 'somevalue' but depend on php logic, sometimes i need to get all rows, where name = somethimg, independently of order value. i don't want to change the query structure, because in practise there are many number of fields, and possible count of queries will became very big. so i want to save the structure of query, and when i need to select just by name, i want to write something like this select `id` from `table` where `name` = 'something' and `order` = any value is it possible? maybe the question is incomprehensible, at least i tried;) sorry for bad english thanks

  Read the article

• Recursive query question - break rows into columns?

  - by Stew

  I have a table "Families", like so FamilyID PersonID Relationship ----------------------------------------------- F001 P001 Son F001 P002 Daughter F001 P003 Father F001 P004 Mother F002 P005 Daughter F002 P006 Mother F003 P007 Son F003 P008 Mother and I need output like FamilyID PersonID Father Mother ------------------------------------------------- F001 P001 P003 P004 F001 P002 P003 P004 F001 P003 F001 P004 F002 P005 P006 F002 P006 F003 P007 P008 F003 P008 In which the PersonID of the Father and Mother for a given PersonID are listed (if applicable) in separate columns. I know this must be a relatively trivial query to write (and therefore to find instructions for), but I can't seem to come up with the right search terms. Searching "SQL recursive queries" has gotten me closest, but I can't quite translate those methods to what I'm trying to do here. I'm trying to learn, so multiple methods are welcome, as is vocabulary I should read up on. Thanks!

  Read the article

• Question about mysql indexes on low to medium cardinality columns

  - by Kevin J

  I have a general question about the way that database indexing works, particularly in mysql. Let's say I have a table with a million rows with a column "ClientID" that is distributed relatively equally among 30 values. Thus, this column is very low cardinality (30) relative to the primary key (1 million). Now, I understand that you shouldn't create indexes on low cardinality fields. However, in this case, queries are only ever done with one of the 30 clientIDs. Thus, wouldn't creating an index on ClientID be helpful, as the search space is automatically reduced to 1/30th what it normally would be? Or is my understanding of how the index works flawed? Thanks

  Read the article

• Management Studio default file save location

  - by jayrdub

  Open a new query window. Write some SQL. Save the script, the Save File As dialog box opens - but always to the same default location in the Profiles directory. Is there any way to set my default file location? ...Like I used to do with apps from the 1980s? Under Tools|Options a default location can be specified for query results. I need the same thing for new queries (the text editor). Tried changing locations in the Registry but SSMS just overwrote my changes. Any suggestions? (I saw this unanswered question at http://www.eggheadcafe.com/software/aspnet/30098335/management-studio-default.aspx and I had same exact question so I just reposted it here)

  Read the article

• Using Rails and Rspec, how do you test that the database is not touched by a method

  - by Will Tomlins

  So I'm writing a test for a method which for performance reasons should achieve what it needs to achieve without using SQL queries. I'm thinking all I need to know is what to stub: describe SomeModel do describe 'a_getter_method' do it 'should not touch the database' do thing = SomeModel.create something_inside_rails.should_not_receive(:a_method_querying_the_database) thing.a_getter_method end end end EDIT: to provide a more specific example: class Publication << ActiveRecord::Base end class Book << Publication end class Magazine << Publication end class Student << ActiveRecord::Base has_many :publications def publications_of_type(type) #this is the method I am trying to test. #The test should show that when I do the following, the database is queried. self.publications.find_all_by_type(type) end end describe Student do describe "publications_of_type" do it 'should not touch the database' do Student.create() student = Student.first(:include => :publications) #the publications relationship is already loaded, so no need to touch the DB lambda { student.publications_of_type(:magazine) }.should_not touch_the_database end end end So the test should fail in this example, because the rails 'find_all_by' method relies on SQL.

  Read the article

• Best performance approach to history mechanism?

  - by Royi Namir

  We are going to create History Mechanism for our changes in DB (DART in pic) via Triggers. we have 600 tables. Each record that will be changed - the trigger will insert the deleted one into XXX. regarding to the XXX : option 1 : clone each table in "Dart" DB and each table now will have a "sister table" e.g. : Table1 will have Table1_History problems : we will have 1200 tables programmer can do mistakes by working on wrong tables... option 2 : make a new DB (DART_2005 in pic) and the history tables will be there option 3 : use linked server which stores the Db which will contain the history tables. question : 1) which option gives the best performance ( I guess 3 is not - but is it 1 or 2 or same ?) 2) Does option 2 is acting like "linked server" ( in queries we will need to select from both DB's...) 3) What is the best practice approach ?

  Read the article

• Linq for two tables

  - by Diana

  I need to do something like this, My two tables have the same signature, but different class so It suppose to work but it is not working. var myTable; if (booleanVariable == true) { myTable = table1; } else { myTable = table2; } var myLinq1 = from p in myTable join r in myOtherTable select p; In this case, I have to initialize myTable I have tried also, var myTablev= table2; if (booleanVariable == true) { myTable = table1; } var myLinq1 = from p in myTable join r in myOtherTable select p; then var is type table2, then it can't be changed to table1 type. I need help, I don't want to make a copy paste of all the code. the linq query is huge, and it s nested with 5 or 6 queries. also I have to do this on 12 different methods. Thanks a lot for your help.

  Read the article

• XSD generation from a MS SQL database using schemas

  - by madprog

  I'm willing to use NDbUnit on a MS SQL database which uses schemas. I have to generate the XSD schema from the database. Visual Studio has a tool to do that, but Visual Studio 2005 doesn't include the schema information in the generated XSD. Therefore, NDbUnit fails because the generated SQL queries do not match the database. Worse, when I try to use Proteus, the XSD schema doesn't validate against the database, and Proteus fails with a warning telling that data could be lost if this check was skipped. So, my question is: is there any tool that would generate my XSD schema properly and from the database information?

  Read the article

• WSSQL query for multiple computers at once

  - by Josh

  I can run normal searches just fine. Windows 7 won't let me add a network share to my local index, but I can query the remote index just fine. The problem is that I can't find a way to query two indexes at once. I was hoping that something like this would work: SELECT System.ItemName FROM compA.SystemIndex, compB.SystemIndex WHERE SCOPE='file://compA/pathA' OR SCOPE='file://compB/pathB' but it doesn't. For simple queries, I can query compA and compB separately and then merge the results myself, but I'm hoping for a better way. Anybody here have some experience with this?

  Read the article

• Duplicate an AppEngine Query object to create variations of a filter without affecting the base quer

  - by Steve Mayne

  In my AppEngine project I have a need to use a certain filter as a base then apply various different extra filters to the end, retrieving the different result sets separately. e.g.: base_query = MyModel.all().filter('mainfilter', 123) Then I need to use the results of various sub queries separately: subquery1 = basequery.filter('subfilter1', 'xyz') #Do something with subquery1 results here subquery2 = basequery.filter('subfilter2', 'abc') #Do something with subquery2 results here Unfortunately 'filter()' affects the state of the basequery Query instance, rather than just returning a modified version. Is there any way to duplicate the Query object and use it as a base? Is there perhaps a standard Python way of duping an object that could be used? The extra filters are actually applied by the results of different forms dynamically within a wizard, and they use the 'running total' of the query in their branch to assess whether to ask further questions. Obviously I could pass around a rudimentary stack of filter criteria, but I'd rather use the Query itself if possible, as it adds simplicity and elegance to the solution.

  Read the article

• What is difference between Where and Join in linq ?

  - by Freshblood

  hello What is difference between of these 2 queries ? they are completely equal ? from order in myDB.OrdersSet from person in myDB.PersonSet from product in myDB.ProductSet where order.Persons_Id==person.Id && order.Products_Id==product.Id select new { order.Id, person.Name, person.SurName, product.Model,UrunAdi=product.Name }; and from order in myDB.OrdersSet join person in myDB.PersonSet on order.Persons_Id equals person.Id join product in myDB.ProductSet on order.Products_Id equals product.Id select new { order.Id, person.Name, person.SurName, product.Model,UrunAdi=product.Name };

  Read the article

• Retrieving data from MySQL in one SQL statement

  - by james.ingham

  Hi all, If I'm getting my data from Mysql like so: $result = $dbConnector->Query("SELECT * FROM branches, businesses WHERE branches.BusinessId = businesses.Id ORDER BY businesses.Name"); $resultNum = $dbConnector->GetNumRows($result); if($resultNum > 0) { for($i=0; $i < $resultNum; $i++) { $row = $dbConnector->FetchArray($result); // $row['businesses.Name']; // $row['branches.Name']; echo $row['Name']; } } Does anyone know how to print the field Name in businesses and how to print the name from branches? My only other alternative is to rename the fields or to call Mysql with two seperate queries. Thanks in advance

  Read the article

• SQL Server 2008 - Search Query

  - by user208662

  Hello, I am not a SQL Expert. I’m trying to elegantly solve a query problem that others have had to have had. Surprisingly, Google is not returning anything that is helping. Basically, my application has a “search” box. This search field will allow a user to search for customers in the system. I have a table called “Customer” in my SQL Server 2008 database. This table is defined as follows: Customer UserName (nvarchar) FirstName (nvarchar) LastName (nvarchar) As you can imagine, my users will enter queries of varying cases and probably mis-spell the customer’s names regularly. How do I query my customer table and return the 25 results that are closest to their query? I have no idea how to do this ranking and consider the three fields listed in my table. Thank you!

  Read the article

• Is an ORM redundant with a NoSQL API?

  - by Earlz

  Hello, with MongoDB (and I assume other NoSQL database APIs worth their salt) the ways of querying the database are much more simplistic than SQL. There is no tedious SQL queries to generate and such. For instance take this from mongodb-csharp: using MongoDB.Driver; Mongo db = new Mongo(); db.Connect(); //Connect to localhost on the default port. Document query = new Document(); query["field1"] = 10; Document result = db["tests"]["reads"].FindOne(query); db.Disconnect(); How could an ORM even simplify that? Is an ORM or other "database abstraction device" required on top of a decent NoSQL API?

  Read the article

• Autmatically create table on MySQL server based on date?

  - by Anthony

  Is there an equivalent to cron for MySQL? I have a PHP script that queries a table based on the month and year, like: SELECT * FROM data_2010_1 What I have been doing until now is, every time the script executes it does a query for the table, and if it exists, does the work, if it doesn't it creates the table. I was wondering if I can just set something up on the MySQL server itself that will create the table (based on a default table) at the stroke of midnight on the first of the month. Update Based on the comments I've gotten, I'm thinking this isn't the best way to achieve my goal. So here's two more questions: If I have a table with thousands of rows added monthly, is this potentially a drag on resources? If so, what is the best way to partition this table, since the above is verboten? What are the potential problems with my home-grown method I originally thought up?

  Read the article

• toplink prefixes table with TL_ while update operation

  - by Dewfy

  I have very simple named query on JPA (toplink ): UPDATE Server s SET s.isECM = 0 I don't carry about cache or validity of already preloaded entities. But database connection is performed from restricted account (only INSERT/UPDATE/DELETE). It is appeared that toplink on this query executes (and failed since TL_Server is not exists) very strange SQL: INSERT INTO TL_Server (elementId, IsECM) SELECT t0.ElementId, ? FROM Element t0, Server t1 WHERE ((t1.elementId = t0.ElementId) AND (t0.elementType = ?)) bind => [0, Server] What is this? How the simple UPDATE appears an INSERT? Why toplink queries TL_?

  Read the article

• Need an alternative to two left joins.

  - by Scarface

  Hey guys quick question, I always use left join, but when I left join twice I always get funny results, usually duplicates. I am currently working on a query that Left Joins twice to retrieve the necessary information needed but I was wondering if it were possible to build another select statement in so then I do not need two left joins or two queries or if there were a better way. For example, if I could select the topic.creator in table.topic first AS something, then I could select that variable in users and left join table.scrusersonline. Thanks in advance for any advice. SELECT * FROM scrusersonline LEFT JOIN users ON users.id = scrusersonline.id LEFT JOIN topic ON users.username = topic.creator WHERE scrusersonline.topic_id = '$topic_id' The whole point of this query is to check if the topic.creator is online by retrieving his name from table.topic and matching his id in table.users, then checking if he is in table.scrusersonline. It produces duplicate entries unfortunately and is thus inaccurate in my mind.

  Read the article

• Microsoft SQL Server 2008 - 99% fragmentation on non-clustered, non-unique index

  - by user550441

  I have a table with several indexes (defined below). One of the indexes (IX_external_guid_3) has 99% fragmentation regardless of rebuilding/reorganizing the index. Anyone have any idea as to what might cause this, or the best way to fix it? We are using Entity Framework 4.0 to query this, the EF queries on the other indexed fields about 10x faster on average then the external_guid_3 field, however an ADO.Net query is roughly the same speed on both (though 2x slower than the EF Query to indexed fields). Table id(PK, int, not null) guid(uniqueidentifier, null, rowguid) external_guid_1(uniqueidentifier, not null) external_guid_2(uniqueidentifier, null) state(varchar(32), null) value(varchar(max), null) infoset(XML(.), null) -- usually 2-4K created_time(datetime, null) updated_time(datetime, null) external_guid_3(uniqueidentifier, not null) FK_id(FK, int, null) locking_guid(uniqueidentifer, null) locked_time(datetime, null) external_guid_4(uniqueidentifier, null) corrected_time(datetime, null) is_add(bit, not null) score(int, null) row_version(timestamp, null) Indexes PK_table(Clustered) IX_created_time(Non-Unique, Non-Clustered) IX_external_guid_1(Non-Unique, Non-Clustered) IX_guid(Non-Unique, Non-Clustered) IX_external_guid_3(Non-Unique, Non-Clustered) IX_state(Non-Unique, Non-Clustered)

  Read the article

• SQL 2005 w/ C# optimal "Paging"

  - by David Murdoch

  When creating a record "grid" with custom paging what is the best/optimal way to query the total number of records as well as the records start-end using C#? SQL to return paged record set: SELECT Some, Columns, Here FROM ( SELECT ROW_NUMBER() OVER (ORDER BY Column ASC) AS RowId, * FROM Records WHERE (...) ) AS tbl WHERE ((RowId > @Offset) AND (RowId <= (@Offset + @PageSize)) ) SQL to count total number of records: SELECT COUNT(*) FROM Records WHERE (...) Right now, I make two trips to the server: one for getting the records, and the other for counting the total number of records. What is/are the best way(s) to combine these queries to avoid multiple DB trips?

  Read the article

• LINQ to SQL: making a "double IN" query crashes

  - by Alex

  I need to do the following thing: var a = from c in DB.Customers where (from t1 in DB.Table1 where t1.Date >= DataTime.Now select t1.ID).Contains(c.ID) && (from t2 in DB.Table2 where t2.Date >= DataTime.Now select t2.ID).Contains(c.ID) select a It doesn't want to run. I get the following error: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. But when I try to run var a = from c in DB.Customers where (from t1 in DB.Table1 where t1.Date >= DataTime.Now select t1.ID).Contains(c.ID) select a OR var a = from c in DB.Customers where (from t2 in DB.Table2 where t2.Date = DataTime.Now select t2.ID).Contains(c.ID) select a It works! I'm sure that there both IN queries contain some customers ids.

  Read the article

< Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >