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Interesting and challenging self join problem SQL Server 2005

I have this table named OrdersToCall Data types: All bigints, except for date which is a datetime |-Order Num-|----Date--- |- Primary Ph -| Secondary Ph | Alternate Ph |----101----| 02-07-2010 | 925-515-1234 | 916-515-1234 | 707-568-5778 |----102----| 02-07-2010 | 925-888-4141 | 925-888-4141 | 000-000-0000 |----103----| 02-07-2010 ...

MySQL Count Items In Category

I don't understand MySQL very well, here are the table structures I am using. users id | first_name | last_name | username | password categories id | user_id | name | description links id | user_id | category_id | name | url | description | date_added | hit_counter I am trying to return a result set like this, to...

What is a good approach in MS SQL Server 2008 to join on a "best" match?

In essence I want to pick the best match of a prefix from the "Rate" table based on the TelephoneNumber field in the "Call" table. Given the example data below, '0123456789' would best match the prefix '012' whilst '0100000000' would best match the prefix '01'. I've included some DML with some more examples of correct matches in the SQL...

Deadlock caused by SELECT JOIN statement with SQL Server

When executing a SELECT statement with a JOIN of two tables SQL Server seems to lock both tables of the statement individually. For example by a query like this: SELECT ... FROM table1 LEFT JOIN table2 ON table1.id = table2.id WHERE ... I found out that the order of the locks depends on the WHERE condition. The que...

How to reduce MySQL query execution time from 90 seconds to less than 5 seconds or even one second

I am using MySQL database. When I execute a query which the main table(20 thousands of rows) is joined with the other 5 tables, it takes 90 seconds to return me the result. I then added indices into each of the criteria(where clause). Then the execution time drops from 90 seconds to 45 seconds and then I tried to select only necessary fi...

Using single query to retrieve multivalued attribute by joining two tables without causing duplication of fields in mysql

Table 1 : QUERY: Create table client ( applicationNo int primary key, name varchar(20) ); Insert statement: Insert into client values (1,'XYZ'),(1,'ABC'),(1,'DEF'); applicationNo | name 1 | XYZ 2 | ABC 3 | DEF Table 2: Query : Create table client ( applicationNo int, ...

can't do :joins without writing SQL code

I can't understand why this code works: @ads = Ads.find( :all, :joins => "INNER JOIN ad_users u ON u.ad_users_id=ads.ad_users_id" ) and this one doesn't: @ads = Ads.find( :all, :joins => :AdUsers ) my classes are: class Ads < ActiveRecord::Base set_primary_key :ads_id belongs_to :AdUsers end and class AdU...

Is it always a good practice to use aliases in sql joins or nested queries?

Is it always a best practice to use - Select E.Id,D.DeptName from Employee E join Dept D on E.DeptId=D.Id instead of - Select Employee.Id,Dept.DeptName from Employee join Dept on Employee.DeptId=Dept.Id Other than readability and reducing length of the query what are benefits of using aliases ? When I consulted with our Database ex...

MySQL JOIN help

Hello, I hate asking for code but I just can't seem to do the below - Staff | lastname - name - position | | Henderson | John | A | | Howard | Bob | B | | Hendry | Chris | B | Max_person | lastname - change | | Henderson | John | | Howard | Bob | | Hendry ...

MySQL JOIN table query help

Hello, I hate asking for code but I just can't seem to do the below - Staff | lastname - name - position | | Henderson | John | A | | Howard | Bob | B | | Hendry | Chris | B | Max_person | lastname - change | | Henderson | 0.9 | | Howard | 0.2 | | Hendry ...

Greater Than Condition in Linq Join

I had tried to join two table conditionally but it is giving me syntax error. I tried to find solution in the net but i cannot find how to do conditional join with condition. The only other alternative is to get the value first from one table and make a query again. I just want to confirm if there is any other way to do conditional join...

combine two lists with a join on a column

I'm trying to combine two lists, joining them by a common field suchs as ENST00000371026. I've tried the following but no luck. What is the actual way to do it? cat> gar1.txt <<EOF ENST00000371026 ENSG00000152763 ENST00000371023 ENSG00000152763 ENST00000395250 ENSG00000152763 ENST00000309502 ENSG00000163485 ENST00000377464 ENSG00000142...

Help with complex join conditions

I have the following mysql table schema: SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO"; -- -- Database: `network` -- -- -------------------------------------------------------- -- -- Table structure for table `contexts` -- CREATE TABLE IF NOT EXISTS `contexts` ( `id` int(11) NOT NULL AUTO_INCREMENT, `keyword` varchar(255) NOT NULL, PRI...

Serialize a HashSet<String> with LinQ

I'd like to take a HashSet<String> and elegantly convert it to a string. I can iterate like so: HashSet<String> words = new HashSet<string>() { "alpha", "beta", "delta" }; string joined = ""; foreach (var w in words) joined += w + ","; if(joined.Length > 0) joined = joined.SubString(0,joined.Length-1); // remove final comma Is ...

MySQL Query Multiple Joins with Incorrect Results

I have 3 tables structured like so: activity table: activity_id, user_id, type, date reviews table: review_id, activity_id, fishery_id, review, date updates table: update_id, activity_id, update, date I want to call the all the reviews and updates which are linked to a user by the activity table however this query retu...

sql join syntax

I'm kind of new to writing sql and I have a question about joins. Here's an example select: select bb.name from big_box bb, middle_box mb, little_box lb where lb.color = 'green' and lb.parent_box = mb and mb.parent_box = bb; So let's say that I'm looking for the names of all the big boxes that have nested somewhere inside them a litt...

How do I do mysql join statement on multiple table hierarchy levels?

Suppose I have the following table house: House: id name cityID Where cityID refers to the id field of table city City: id name stateID where stateID refers to the id field of table state State: id name countryID where countryID refers to the id field of the table country: Country: id name How do I do mysql join statements s...

Order rows in join table mysql

I have a table with date ranges. I want to look for gaps between these ranges. I've figured out that I may left join table to itself and calculate the difference. Current table: date_begin date_end 2010-08-01 2010-08-15 2010-08-16 2010-08-30 2010-08-31 2010-09-12 2010-10-01 2010-10-15 I want to get: date_begin date...

join multiple fields to one table

I have 2 tables (there are more but un related to question) optionValue and productStock I want to get the option names from the optionValue table for each option1, option2, option3 (the query below will should help to make more sense) below is my attempt, the current query it only works if all options are set but is returns null if a...

[SYBASE] SQL query for "concatenate on join"

NOTE: I'm still looking for an answer that I can accept. Hi, I'm using a Sybase ASE database. I have two tables that look like: Table Shops: --------------------- | ShopName | ShopID | --------------------- | Sweetie | 1 | | Candie | 2 | | Sugarie | 3 | --------------------- Table Sweets: --------------------...