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  • Performance degrades for more than 2 threads on Xeon X5355

    - by zoolii
    Hi All, I am writing an application using boost threads and using boost barriers to synchronize the threads. I have two machines to test the application. Machine 1 is a core2 duo (T8300) cpu machine (windows XP professional - 4GB RAM) where I am getting following performance figures : Number of threads :1 , TPS :21 Number of threads :2 , TPS :35 (66 % improvement) further increase in number of threads decreases the TPS but that is understandable as the machine has only two cores. Machine 2 is a 2 quad core ( Xeon X5355) cpu machine (windows 2003 server with 4GB RAM) and has 8 effective cores. Number of threads :1 , TPS :21 Number of threads :2 , TPS :27 (28 % improvement) Number of threads :4 , TPS :25 Number of threads :8 , TPS :24 As you can see, performance is degrading after 2 threads (though it has 8 cores). If the program has some bottle neck , then for 2 thread also it should have degraded. Any idea? , Explanations ? , Does the OS has some role in performance ? - It seems like the Core2duo (2.4GHz) scales better than Xeon X5355 (2.66GHz) though it has better clock speed. Thank you -Zoolii

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  • convert MsSql StoredPorcedure to MySql

    - by karthik
    I need to covert the following SP of MsSql To MySql. I am new to MySql.. Help needed. CREATE PROC InsertGenerator (@tableName varchar(100)) as --Declare a cursor to retrieve column specific information --for the specified table DECLARE cursCol CURSOR FAST_FORWARD FOR SELECT column_name,data_type FROM information_schema.columns WHERE table_name = @tableName OPEN cursCol DECLARE @string nvarchar(3000) --for storing the first half --of INSERT statement DECLARE @stringData nvarchar(3000) --for storing the data --(VALUES) related statement DECLARE @dataType nvarchar(1000) --data types returned --for respective columns SET @string='INSERT '+@tableName+'(' SET @stringData='' DECLARE @colName nvarchar(50) FETCH NEXT FROM cursCol INTO @colName,@dataType IF @@fetch_status<0 begin print 'Table '+@tableName+' not found, processing skipped.' close curscol deallocate curscol return END WHILE @@FETCH_STATUS=0 BEGIN IF @dataType in ('varchar','char','nchar','nvarchar') BEGIN SET @stringData=@stringData+'''''''''+ isnull('+@colName+','''')+'''''',''+' END ELSE if @dataType in ('text','ntext') --if the datatype --is text or something else BEGIN SET @stringData=@stringData+'''''''''+ isnull(cast('+@colName+' as varchar(2000)),'''')+'''''',''+' END ELSE IF @dataType = 'money' --because money doesn't get converted --from varchar implicitly BEGIN SET @stringData=@stringData+'''convert(money,''''''+ isnull(cast('+@colName+' as varchar(200)),''0.0000'')+''''''),''+' END ELSE IF @dataType='datetime' BEGIN SET @stringData=@stringData+'''convert(datetime,''''''+ isnull(cast('+@colName+' as varchar(200)),''0'')+''''''),''+' END ELSE IF @dataType='image' BEGIN SET @stringData=@stringData+'''''''''+ isnull(cast(convert(varbinary,'+@colName+') as varchar(6)),''0'')+'''''',''+' END ELSE --presuming the data type is int,bit,numeric,decimal BEGIN SET @stringData=@stringData+'''''''''+ isnull(cast('+@colName+' as varchar(200)),''0'')+'''''',''+' END SET @string=@string+@colName+',' FETCH NEXT FROM cursCol INTO @colName,@dataType END

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  • MySQL table data transformation -- how can I dis-aggreate MySQL time data?

    - by lighthouse65
    We are coding for a MySQL data warehousing application that stores descriptive data (User ID, Work ID, Machine ID, Start and End Time columns in the first table below) associated with time and production quantity data (Output and Time columns in the first table below) upon which aggregate (SUM, COUNT, AVG) functions are applied. We now wish to dis-aggregate time data for another type of analysis. Our current data table design: +---------+---------+------------+---------------------+---------------------+--------+------+ | User ID | Work ID | Machine ID | Event Start Time | Event End Time | Output | Time | +---------+---------+------------+---------------------+---------------------+--------+------+ | 080025 | ABC123 | M01 | 2008-01-24 16:19:15 | 2008-01-24 16:34:45 | 2120 | 930 | +---------+---------+------------+---------------------+---------------------+--------+------+ Reprocessing dis-aggregation that we would like to do would be to transform table content based on a granularity of minutes, rather than the current production event ("Event Start Time" and "Event End Time") granularity. The resulting reprocessing of existing table rows would look like: +---------+---------+------------+---------------------+--------+ | User ID | Work ID | Machine ID | Production Minute | Output | +---------+---------+------------+---------------------+--------+ | 080025 | ABC123 | M01 | 2010-01-24 16:19 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:20 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:21 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:23 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:24 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:25 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:26 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:27 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:28 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:29 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:30 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:31 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:33 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:34 | 133 | +---------+---------+------------+---------------------+--------+ So the reprocessing would take an existing row of data created at the granularity of production event and modify the granularity to minutes, eliminating redundant (Event End Time, Time) columns while doing so. It assumes a constant rate of production and divides output by the difference in minutes plus one to populate the new table's Output column. I know this can be done in code...but can it be done entirely in a MySQL insert statement (or otherwise entirely in MySQL)? I am thinking of a INSERT ... INTO construction but keep getting stuck. An additional complexity is that there are hundreds of machines to include in the operation so there will be multiple rows (one for each machine) for each minute of the day. Any ideas would be much appreciated. Thanks.

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  • Problem with date_select when using :discard option. (Rails)

    - by MikeH
    I'm using a date_select with the option :discard_year => true If a user selects a date in the date select, and then he comes back and returns the select to the prompt values of Month and Day, Rails automatically sets the select values to January 1. I know this is the intended functionality if a month is selected and a day is left blank, but that's not the case here. In my example, the user sets both the month and day back to the prompt. By Rails forcing January 1, I'm getting bad results. I've tried every parameter available in the api. :default = nil, :include_blank = true. None of those change the behavior I'm describing. I've isolated the root of the problem, which is this: Because I'm discarding the :year parameter, when the user tries to return the month and day to the prompt values, Rails doesn't see an empty prompt select. It perhaps sees a year selected with empty month and day, which it then sets to January 1. This is the case because the :discard_year parameter does in fact set a date in the database, it just removes it from the view. How can I code around this problem?

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  • How do I make the following interaction with mySQL more efficient?

    - by Travis
    I've got an array that contains combinations of unique MySql IDs: For example: [ [1,10,11], [2,10], [3,10,12], [3,12,13,20], [4,12] ] In total there are a couple hundred different combinations of IDs. Some of these combinations are "valid" and some are not. For example, [1,10,11] may be a valid combination, whereas [3,10,12] may be invalid. Combinations are valid or invalid depending on how the data is arranged in the database. Currently I am using a SELECT statement to determine whether or not a specific combination of IDs is valid. It looks something like this: SELECT id1 FROM table WHERE id2 IN ($combination) GROUP BY id1 HAVING COUNT(distinct id2) = $number ...where $combination is one possible combination of IDs (eg 1,10,11) and $number is the number of IDs in that combination (in this case, 3). An invalid combination will return 0 rows. A valid combination will return 1 or more rows. However, to solve the entire set of possible combinations means looping a couple hundred SELECT statements, which I would rather not be doing. I am wondering: Are there any tricks for making this more efficient? Is it possible to submit the entire dataset to mySQL in one go, and have mySQL iterate through it? Any suggestions would be much appreciated. Thanks in advance!

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  • Can I select a set of Data and directly insert that into a table in SQL?

    - by VJ
    Hi I guess we cannot do this but was just curious if I could do something like - Select * from Employee where EmployeeId=1 and then use the data in the above statement and directly insert into a table with just changing the employeeid...or just this way- insert into Employee ( Select * from Employee where EmployeeId=1) its probably stupid from my side...but I just felt the need to do this a lot of times...so just was curious if there was any way to achieve it..

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  • Is it possible to call a procedure within an SQL statement?

    - by darren
    Hi everyone I thought I would use a stored routine to clean up some of my more complex SQL statements. From what I've read, it seems impossible to use a stored procedure within an sql statement, and a stored function only returns a single value when what I need is a result set. I am using mySQL v5.0 SELECT p.`id`, gi.`id` FROM `sport`.`players` AS p JOIN `sport`.`gameinstances` AS gi ON p.`id` = gi.`playerid` WHERE (p.`playerid` IN (CALL findPlayers`("Canada", "2002"))) AND (gi.`instanceid` NOT IN (CALL findGameInstances`("Canada", "2002"))); For example, the procedures 'findPlayers' and 'findGameInstances' are are stored routines that execute some SQL and return a result set. I would prefer not to include their code directly within the statement above.

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  • php MySQL snytax error

    - by Jacksta
    my scrip is supposed to look up contacts in a table and present thm on the screen to then be edited. however this is not this case. I am getting the error Parse error: syntax error, unexpected $end in /home/admin/domains/domain.com.au/public_html/pick_modcontact.php on line 50 NOTE: this is the last line in this script. <? session_start(); if ($_SESSION[valid] != "yes") { header( "Location: contact_menu.php"); exit; } $db_name = "testDB"; $table_name = "my_contacts"; $connection = @mysql_connect("localhost", "user", "pass") or die(mysql_error()); $db = @mysql_select_db($db_name, $connection) or die(mysql_error()); $sql = "SELECT id, f_name, l_name FROM $table_name ORDER BY f_name"; $result = @mysql_query($sql, $connection) or die(mysql_error()); $num = @mysql_num_rows($result); if ($num < 1) { $display_block = "<p><em>Sorry No Results!</em></p>"; } else { while ($row = mysql_fetch_array($result)) { $id = $row['id']; $f_name = $row['f_name']; $l_name = $row['l_name']; $option_block .= "<option value\"$id\">$l_name, $f_name</option>"; } $display_block = "<form method=\"POST\" action=\"show_modcontact.php\"> <p><strong>Contact:</strong> <select name=\"id\">$option_block</select> <input type=\"submit\" name=\"submit\" value=\"Select This Contact\"></p> </form>"; ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Modify A Contact</title> </head> <body> <h1>My Contact Management System</h1> <h2><em>Modify a Contact</em></h2> <p>Select a contact from the list below, to modify the contact's record.</p> <? echo "$display_block"; ?> <br> <p><a href="contact_menu.php">Return to Main Menu</a></p> </body> </html>

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  • How does mysql define DISTINCT()

    - by goran
    AFAIK SQL defines two uses of DISTINCT keywords - SELECT DISTINCT field... and SELECT COUNT(DISTINCT field) ... However in one of web applications that I administer I've noticed performance issues on queries like SELECT DISTINCT(field1), field2, field3 ... DISTINCT() on a single column makes no sense and I am almost sure it is interpreted as SELECT DISTINCT field1, field2, field3 ... but how can I prove this? I've searched mysql site for a reference on this particular syntax but could not find any. Does anyone have a link to definition of DISTINCT() in mysql or knows about other authoritative source on this? Best

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  • Database time data retrieval, time based queries

    - by Raphael Pineda
    I am new to time manipulation or time arithmetic operations and am currently developing a navigation system with Web server based information and currently I have this Database that contains a table peek hours whose columns are id, start_time, end_time , edge_id, day_of_the_week, edge_weight ------------------------------------------------------------------------ | Peek Hours | ------------------------------------------------------------------------ | | | | | | | | id | start_time | end_time | edge_id | day_of_the_week | edge_weight | | | | | | | | ------------------------------------------------------------------------ I am using PHP as a webservice and so based on the current time i want to get all the records that would fit this equation start_time< current_time < end_time

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  • MySqli Prepared Statment Fetch Row

    - by pws5068
    I'm looking for an efficient way to select a specific row with a php prepared statement. $iDB = new mysqliDB(); $stmt = $iDB->prepare($sql); $stmt->bind_param('s',$searhStr); $stmt->execute(); $stmt->store_result(); $stmt->bind_result($objID,$typeID,$year,$updated); // Now jump to row $rowNumber echo("Obj ID = {$objID}"); Any suggestions? Thanks!

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  • Listing mysql row entries from tags into one single row

    - by Derrick
    Hi guys, Ive got two tables, one a listings and another representing a list of tags for the listing table. In the listings table the tag ids are stored in a field called tags as 1-2-3- this has worked out very well for me regular expressions and joins to seperate and display the data, BUT... I now need to pull the titles of those tags into a single row. See below. listings table id tags 1 1-2-3- 2 4-5-6- tags table id title 1 pig 2 dog 3 cat 4 mouse 5 elephant 6 duck And what I need to produce out of the listings table is: id tags 2 mouse, elephant, duck any suggestions?

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  • Insert statement with where clause.

    - by debraj
    I had a table with unique Date_t1 date type field, but in Table description field is not mentioned as unique, now while inserting new row i need to validate if date exist or not, If already exist i should not allow to make changes on that row, neither a new row needs to be created, Any idea how to resolve this problem in efficient way,

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  • Correlate GROUP BY and LEFT JOIN on multiple criteria to show latest record?

    - by Sunbird
    In a simple stock management database, quantity of new stock is added and shipped until quantity reaches zero. Each stock movement is assigned a reference, only the latest reference is used. In the example provided, the latest references are never shown, the stock ID's 1,4 should have references charlie, foxtrot respectively, but instead show alpha, delta. How can a GROUP BY and LEFT JOIN on multiple criteria be correlated to show the latest record? http://sqlfiddle.com/#!2/6bf37/107 CREATE TABLE stock ( id tinyint PRIMARY KEY, quantity int, parent_id tinyint ); CREATE TABLE stock_reference ( id tinyint PRIMARY KEY, stock_id tinyint, stock_reference_type_id tinyint, reference varchar(50) ); CREATE TABLE stock_reference_type ( id tinyint PRIMARY KEY, name varchar(50) ); INSERT INTO stock VALUES (1, 10, 1), (2, -5, 1), (3, -5, 1), (4, 20, 4), (5, -10, 4), (6, -5, 4); INSERT INTO stock_reference VALUES (1, 1, 1, 'Alpha'), (2, 2, 1, 'Beta'), (3, 3, 1, 'Charlie'), (4, 4, 1, 'Delta'), (5, 5, 1, 'Echo'), (6, 6, 1, 'Foxtrot'); INSERT INTO stock_reference_type VALUES (1, 'Customer Reference'); SELECT stock.id, SUM(stock.quantity) as quantity, customer.reference FROM stock LEFT JOIN stock_reference AS customer ON stock.id = customer.stock_id AND stock_reference_type_id = 1 GROUP BY stock.parent_id

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  • How can I order by the result of a recursive SQL query

    - by Tony
    I have the following method I need to ORDER BY: def has_attachments? attachments.size > 0 || (!parent.nil? && parent.has_attachments?) end I have gotten this far: ORDER BY CASE WHEN attachments.size > 0 THEN 1 ELSE (CASE WHEN parent_id IS NULL THEN 0 ELSE (CASE message.parent ...what goes here ) END END END I may be looking at this wrong because I don't have experience with recursive SQL. Essentially I want to ORDER by whether a message or any of its parents has attachments. If it's attachment size is 0, I can stop and return a 1. If the message has an attachment size of 0, I now check to see if it has a parent. If it has no parent then there is no attachment, however if it does have a parent then I essentially have to do the same query case logic for the parent. UPDATE The table looks like this +---------------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | message_type_id | int(11) | NO | MUL | | | | message_priority_id | int(11) | NO | MUL | | | | message_status_id | int(11) | NO | MUL | | | | message_subject_id | int(11) | NO | MUL | | | | from_user_id | int(11) | YES | MUL | NULL | | | parent_id | int(11) | YES | MUL | NULL | | | expires_at | datetime | YES | MUL | NULL | | | subject_other | varchar(255) | YES | | NULL | | | body | text | YES | | NULL | | | created_at | datetime | NO | MUL | | | | updated_at | datetime | NO | | | | | lock_version | int(11) | NO | | 0 | | +---------------------+--------------+------+-----+---------+----------------+ Where the parent_id refers to the parent message, if it exists. Thanks!

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  • PHP: table structure

    - by A3efan
    I'm developing a website that has some audio courses, each course can have multiple lessons. I want to display each course in its own table with its different lessons. This is my sql statement: Table: courses id, title Table: lessons id, cid (course id), title, date, file $sql = "SELECT lessons.*, courses.title AS course FROM lessons INNER JOIN courses ON courses.id = lessons.cid GROUP BY lessons.id ORDER BY lessons.id" ; Can someone help me with the PHP code? This is the I code I have written: mysql_select_db($database_config, $config); mysql_query("set names utf8"); $sql = "SELECT lessons.*, courses.title AS course FROM lessons INNER JOIN courses ON courses.id = lessons.cid GROUP BY lessons.id ORDER BY lessons.id" ; $result = mysql_query($sql) or die(mysql_error()); while ($row = mysql_fetch_assoc($result)) { echo "<p><span class='heading1'>" . $row['course'] . "</span> </p> "; echo "<p class='datum'>Posted onder <a href='*'>*</a>, latest update on " . strftime("%A %d %B %Y %H:%M", strtotime($row['date'])); } echo "</p>"; echo "<class id='text'>"; echo "<p>...</p>"; echo "<table border: none cellpadding='1' cellspacing='1'>"; echo "<tr>"; echo "<th>Nr.</th>"; echo "<th width='450'>Lesso</th>"; echo "<th>Date</th>"; echo "<th>Download</th>"; echo "</tr>"; echo "<tr>"; echo "<td>" . $row['nr'] . "</td>"; echo "<td>" . $row['title'] . "</td>"; echo "<td>" . strftime("%d/%m/%Y", strtotime($row['date'])) . "</td>"; echo "<td><a href='audio/" . rawurlencode($row['file']) . "'>MP3</a></td>"; echo "</tr>"; echo "</table>"; echo "<br>"; } ?>

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  • Facebook multiquery result goes wrong?

    - by Simon
    This is my xml result return from facebook <fql_result_set list="true" xmlns="http://api.facebook.com/1.0/"> <comment> <object_id340982187784 </fql_result_set> <fql_result_set list="true" xmlns="http://api.facebook.com/1.0/"> <fql_result_set_elt list="true"> <fql_result_set_elt_elt key="object_id"340982187784811202784 The comment tag part is ok. After the comments you see the fql_result_set_elt and fql_result_elt_elt, this is the part goes wrong. fql_result_set_elt = like tag fql_result_set_elt_elt = object_id tag or user_id instead of having it on key attribute under fql_result_elt_elt

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  • SQL: GROUP BY after JOIN without overriding rows?

    - by krismeld
    I have a table of basketball leagues, a table af teams and a table of players like this: LEAGUES ID | NAME | ------------------ 1 | NBA | 2 | ABA | TEAMS: ID | NAME | LEAGUE_ID ------------------------------ 20 | BULLS | 1 21 | KNICKS | 2 PLAYERS: ID | TEAM_ID | FIRST_NAME | LAST_NAME | --------------------------------------------- 1 | 21 | John | Starks | 2 | 21 | Patrick | Ewing | Given a League ID, I would like to retrieve all the players' names and their team ID from all the teams in that league, so I do this: SELECT t.id AS team_id, p.id AS player_id, p.first_name, p.last_name FROM teams AS t JOIN players AS p ON p.team_id = t.id WHERE t.league_id = 1 which returns: [0] => stdClass Object ( [team_id] => 21 [player_id] => 1 [first_name] => John [last_name] => Starks ) [1] => stdClass Object ( [team_id] => 21 [player_id] => 2 [first_name] => Patrick [last_name] => Ewing ) + around 500 more objects... Since I will use this result to populate a dropdown menu for each team containing each team's list of players, I would like to group my result by team ID, so the loop to create these dropdowns will only have to cycle through each team ID instead of all 500+ players each time. But when I use the GROUP BY like this: SELECT t.id AS team_id, p.id AS player_id, p.first_name, p.last_name FROM teams AS t JOIN players AS p ON p.team_id = t.id WHERE t.league_id = 1 GROUP BY t.id it only returns one player from each team like this, overriding all the other players on the same team because of the use of the same column names. [0] => stdClass Object ( [team_id] => 21 [player_id] => 2 [first_name] => Patrick [last_name] => Ewing ) [1] => stdClass Object ( [team_id] => 22 [player_id] => 31 [first_name] => Shawn [last_name] => Kemp ) etc... I would like to return something like this: [0] => stdClass Object ( [team_id] => 2 [player_id1] => 1 [first_name1] => John [last_name1] => Starks [player_id2] => 2 [first_name2] => Patrick [last_name2] => Ewing +10 more players from this team... ) +25 more teams... Is it possible somehow?

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  • Testing for existence using SELECT WHERE HAVING and NOT HAVING in a grouped subset

    - by IanC
    I have data on which I need to count +1 if a particular condition exists or another condition doesn't exist. I'm using SQL Server 2008. I shred the following simplified sample XML into a temp table and validate it: <product type="1"> <param type="1"> <item mode="0" weight="1" /> </param> <param type="2"> <item mode="1" weight="1" /> <item mode="0" weight="0.1" /> </param> <param type="3"> <item mode="1" weight="0.75" /> <item mode="1" weight="0.25" /> </param> </product> The validation in concern is the following rule: For each product type, for each param type, mode may be 0 & (1 || 2). In other words, there may be a 0(s), but then 1s or 2s are required, or there may be only 1(s) or 2(s). There cannot be only 0s, and there cannot be 1s and 2s. The only part I haven't figured out is how to detect if there are only 0s. This seems like a "not having" problem. The validation code (for this part): WITH t1 AS ( SELECT SUM(t.ParamWeight) AS S, COUNT(1) AS C, t.ProductTypeID, t.ParamTypeID, t.Mode FROM @t AS t GROUP BY t.ProductTypeID, t.ParamTypeID, t.Mode ), ... UNION ALL SELECT TOP (1) 1 -- only mode 0 & (1 || 2) is allowed FROM t1 WHERE t1.Mode IN (1, 2) GROUP BY t1.ProductTypeID, t1.ParamTypeID HAVING COUNT(1) > 1 UNION ALL ... ) SELECT @C = COUNT(1) FROM t2 This will show if any mode 1s & 2s are mixed, but not if the group contains only a 0. I'm sure there is a simple solution, but it's evading me right now. EDIT: I thought of a "cheat" that works perfectly. I added the following to the above: SELECT TOP (1) 1 -- only mode 0 & (null || 1 || 2) is allowed FROM t1 GROUP BY t1.ProductTypeID, t1.ParamTypeID HAVING SUM(t1.Mode) = 0 However, I'd still like to know how to do this without cheating.

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