union

How to merge a large set of polygons with Boost Polygon?

I am looking for a way, using Boost Polygon, to read in a large set of polygons from a file, and output the resulting merge or union to a result file. In this case the polygons touch but do not overlap. I can put the data in any format. Not sure if there is a standard used by Boost Polygon. I am also looking for more documentation on the...

Union, intersect, difference large IntSet in O(m+n) times

from my question http://stackoverflow.com/questions/3601472/insert-element-to-arraylist-with-ascending-order-and-no-duplicate-elements i've done my insert method. Now i try to find out union, intersect, and difference method to operate 2 IntSet. Notice that number elements of IntSet is large and i need to do it in O(m+n) time where ...

Which is the best way to perform this query? Maybe UNION

I have these four tables described bellow. Basically I have feeds with entries relationed with categories, and each category can be a main category or not (flag named as "principal"). Also each feed can be a partner feed or not (flag named as "parceiro"). I want to select all feed entries from partrners feeds, so I have this: SELECT `e...

What could create a syntax error if you take a SQL query and perform an UNION with itself ?

I have this strange error in SQL Server 2005 where I take a working query, add the UNION keyword below it and then copy the query again. In my opinion, this should always be working, but it is not. I get the message 'Incorrect syntax near the keyword 'union'. What could create this problem ? To be more specific, here is the complete q...

The used SELECT statements have a different number of columns

For examples I don't know how many rows in each table are and I try to do like this: SELECT * FROM members UNION SELECT * FROM inventory What can I put to the second SELECT instead of * to remove this error without adding NULL's? ...

performance of union versus union all

I have to run a select statement across several tables. I am sure the tables return different records. I am anyway using UNION ALL. Is it better to use UNION or of UNION ALL in performance terms when I am sure the tables return different records? ...

Combining Union results

I have the below SQL Query select Count(emailID) as ViewsThatMonth, Day(entry_date) as day, Month(entry_date) as month, Year(entry_date) as year from email_views where emailID = 110197 Group By Day(entry_date), Month(entry_date), Year(entry_date) UNION ALL select Count(emailID) as ViewsThatMon...

UNION IN C (What will be the output)

union a { int x; char a[2]; } If we assign 512 value to x and try to print a[0] and a[1] then what will be the output please explain how? ...

RDF/OWL/Protege: let a subclass be a union of some disjoint super classes?

I have following classes: Classes B, C and D are the subclasses of A. A ----+----------> B | +----------> C | +----------> D Besides, I have an object property, hasObjectProperty, and some other classes X, Y, Z, where X, Y, Z are disjoint classes. Then I set restrictions to classes B, C and D as following: (He...

Exclude results from a MySQL UNION query

What is the proper way to exclude results from a MySQL UNION? I'm looking for the equivalent to: (query1) UNION (query2) UNION (query3) EXCEPT (query4) ...

SQL Server: ORDER BY in subquery with UNION

i have two queries being combined with a UNION ALL1: --Query 1 SELECT Flavor, Color FROM Friends   --Query 2 SELECT Flavor, (SELECT TOP 1 Color FROM Rainbows WHERE Rainbows.StrangerID = Strangers.StrangerID ORDER BY Wavelength DESC ) AS Color FROM Strangers Both of which, of course, work fine separately, but ...

Whats the best algorithm for Non Disjoint Set Union ?

Lets say there are two (non disjoint) sets of points (cartesian space), what is the best case complexity algorithm to perform the union of the two sets ? ...

Mixing RAND() and UNION gives random rowcount?

I was testing out a query to get a random integer in MySQL, and I noticed this behavior: mysql> SELECT FLOOR(0 + (RAND() * 5)) UNION SELECT FLOOR(0 + (RAND() * 5)) UNION SELECT FLOOR(0 + (RAND() * 5)); +-------------------------+ | FLOOR(0 + (RAND() * 5)) | +-------------------------+ | 1 | | ...

Selecting columns in UNION

$queryActivities = mysql_query(" SELECT ua.status, ua.date, 'status' AS is_table FROM users_statuslog ua WHERE ua.uid = '{$showU[id]}' UNION ALL SELECT us.message, us.date 'wall' FROM users_wall us WHERE us.uid = '{$showU[id]}' ORDER BY `date` DESC"); This is what I have right now. And I need some more columns from users_wall, ...

MySQL returning results from one table based on data in another table

Before delving into the issue, first I will explain the situation. I have two tables such as the following: USERS TABLE user_id username firstName lastName GROUPS TABLE user_id group_id I want to retrieve all users who's first name is LIKE '%foo%' and who is a part of a group with group_id = 'givengid' So, the query would like somet...

Return all values from IN Clause on SQL Server 2000

Is there a way to retrieve all the data from an IN clause? Let's assume my table got (ID,Name): 0 Banana 1 Mango 2 Papaya 3 Lemon and my query: SELECT * FROM Fruits WHERE Name IN (Banana,Mango,Orange) I Want 'Orange' to return, with an empty ID (since there's no register). How to do this? ...

Implementing C's enum and union in python

I'm trying to figure out some C code so that I can port it into python. The code is for reading a proprietary binary data file format. It has been straightforward thus far -- it's mainly been structs and I have been using the struct library to ask for particular ctypes from the file. However, I just came up on this bit of code and I'm at...

Unions within unions

In C, is it possible to define a union within another union? If no, why is it not possible? Or if yes, where can it be used? ...

SQL UNION issue when counting records

I have the following database schema (names changed to protect the innocent) Code Table | code_id | code_desc | |---------|-----------| | 1 | good | |---------|-----------| | 2 | bad | |---------|-----------| | 3 | ugly | |---------|-----------| Foo Table AssignedFoo Tabl...

UNION ALL, TEXT field and ORDER BY error

Hi, Im having two tables with attributes like date(datetime),headline(varchar),text(text) Now i want to UNION ALL these two tables and sort by the datetime. When doing this i'm getting the error: Only text pointers are allowed in work tables, never text, ntext, or image columns. The query processor produced a query plan that requir...