Combining multiple data points into a single data point. This usually is used in reference to SQL and usually to an aggregate function of some sort.

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nesting MAX for SELECT

I have a table, containing TV series episodes: series: | series_id | season | episode | title | 1 | 1 | 18 | xxx | 1 | 2 | 3 | xxy | 3 | ...
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59 views

Consolidating large table

I need some help with a complex query. Table def: Table "public.agent_log" Column | Type | Modifiers ...
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810 views

How to aggregate pairs of id values into groups

I have a table with two id columns id1 and id2. Each row shows that 2 id values have been linked together. My actual data has both id columns as varchar(20) but I have used integers in the example ...
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2answers
156 views

compare dates in results

I'm looking to compare the dates in the result set Example: SELECT * FROM tbl WHERE foo=bar Output id, datetime, name 1, 2014-01-01 18:13:45, test 1 2, 2014-01-01 19:01:32, test 2 3, 2014-01-01 ...
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638 views

Nested query not recognize external table

i need to a query that show week by week the total amount of imports of any company and in addition add a ranking position depending on that amount. I've made this query but the problem is the inner ...
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1answer
758 views

How can I use running total aggregates in a query to output financial accumulations?

I am attempting to write a query that will be consumed by a SSRS 2012 report. Given a paid invoice, with a certain set of account allocations towards which the money paid towards it must be saved, I ...
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MySQL aggregation count performance

I have a table with about 30 million records, and I'm doing a query where I can group by field Year and count the results for that year. The table structure looks like: id | year | amount The ...
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4answers
22k views

Use of HAVING without GROUP BY in SQL queries

In order to use HAVING in SQL queries , must there be a GROUP BY to aggregate the column names? Are there any special cases where it is possible to use HAVING without a GROUP BY in SQL queries? ...
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Select query to retrieve values even if are null

I need some help in a query. Need to retrieve data from 1 table, even if one of the field has null value. Here's an example: Select name, SUM(credit) as credit From expenses Where name like ...
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2k views

How to get MySQL to iterate a subquery in an aggregate select?

Because the vocabulary describing what I'd like to do can be so disparate, I haven't had any luck figuring out why MySQL 5.6 is doing what it does. Consider the following two simple queries: #1 ...
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223 views

Retrieve title from rows with a maximum count in other columns

Given the following table archived: CREATE TABLE archived ( sid serial -- row id showurl text -- can be: btg, tmwwt, gcaf, emda title text reference text -- title id ...
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761 views

Slow queries related to subqueries using aggregation

Here's a simplified version of the queries I am running: select ... from editions join edition_events on edition_events.edition_id = editions.id join events on events.id = ...
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123 views

How to add up a column depending on data from another column

I have a table which has results and a table that has band_name and band_id. Now I need to create a query which will add up the total points for each band and display the band name and ID, so far I ...
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What is the appropriate SQL method for “Safe to SUM”?

In SQL Server 2008 R2+ we, unfortunately, have some nvarchar columns storing numeric data. In some cases we want to SUM the data when it can be summed. The problem is that ISNUMERIC() returns 1 for a ...
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1answer
441 views

Get maximum from aggregated values in a query

I have a table details it has a column kills and a column player_slot and a column match_id. I want to find the maximum difference between the SUM of kills for player_slot 0-4 and 128-132. Can someone ...
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3answers
392 views

Aggregating data - Getting data inserted after last time query was run

On a SQL Server 2008 R2 DB, I'm running an aggregation query every hour or so, on data that's being constantly inserted into a table, and what I'd like to do is pull all the "new" records that were ...
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2answers
261 views

Query to return fields of distinct values per key

In the process of building a data warehouse we are creating some aggregation tables for a reporting engine. We would like to build a single aggregation table from the fact table that can exist as list ...
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592 views

Column 'Comments.Text' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause

They have explained the root of the problem very well and even advised to use max aggregate as a solution. But, lets take the example group_id item_id comment -------------------------------- ...
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642 views

Index for ORDER BY on aggregate in MySQL

I'm working with the following query: SELECT *, SUM(entries_count) AS entries_count FROM leads WHERE promo_id IN (1, 2, 3) GROUP BY user_id ORDER BY entries_count DESC LIMIT 25 OFFSET 100; It's ...
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How do I get the aggregate of a window function in Postgres?

I have a table containing a two columns of permutations/combinations of integer arrays, and a third column containing a value, like so: CREATE TABLE foo ( perm integer[] NOT NULL, combo integer[] ...
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1k views

Is it possible to reduce a group to a row based on some criteria?

I'd like to perform a select on a table involving a GROUP BY such that all rows that share the same set of identifiers are grouped together, but I want to reduce the group to one of the grouped rows ...
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2answers
9k views

How to select rows which have max and min of count?

I have the following table in SQL Server 2012: CREATE TABLE [MyTable] ( [Id] UNIQUEIDENTIFIER NOT NULL PRIMARY KEY DEFAULT NEWID(), [MyGroup] INT NOT NULL ); I want to output a table of the ...
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4answers
2k views

How can I write windowing query which sums a column to create discrete buckets?

I have a table which includes a column of decimal values, such as this: id value size -- ----- ---- 1 100 .02 2 99 .38 3 98 .13 4 97 .35 5 96 .15 6 95 .57 7 94 .25 ...
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Is using SUM() twice suboptimal?

I know I have to write SUM twice, if I wish to use it in a HAVING clause (or use a derived table otherwise): SELECT id, sum(hours) AS totalhours FROM mytable GROUP BY id HAVING sum(hours) ...
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How to improve the performance for SQL Server Count(distinct()) and Sum() functions? [closed]

The below one is my query. It's taking 12 seconds for the execution process. The count(distinct()) and SUM() functions are taking long time for execution. I tried it after create the non-cluster index ...
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234 views

Mysql: Schema/Query Performance Approach for aggregated mailbox folders

I am about to code a messaging system where users can write messages to other users. User can create custom inbox folders for sorting the messages they receive, however, every user has 2 main inboxes: ...
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7k views

Select first row (grouping) + add aggregate function

First have a look at this question on StackOverflow. I'm looking to accomplish the same task, except I also need to add an aggregate function (PostGIS's ST_Union) to my query. How can I combine the ...
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1answer
497 views

I have multiple sources INSERTing into a MySQL innodb table. My periodic aggregation script never makes accurate aggregates. Why?

I apologize in advance if this is a repeat. I'm not really sure how to properly ask for what I'm running into. I have a large InnoDB table set up. I have 3 sources that all INSERT concurrently at a ...
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1answer
425 views

MongoDB: Aggregation workaround by helper collection

Since I regularly run against mongodb's document size limit and also aggregation framework's group limitations >16M, depending on the amount of data I need to process, I look for a simple workaround. ...
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1answer
605 views

Time as a measure

Is it possible to have times as measures in a cube? We're trying to view employee start times by day, aggregating as an average over time. Even with a No Aggregation measure type I'm getting an error ...
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675 views

How to calculate running total based on dynamic values?

I need to calculate the running total in which the target column is changing along with the time. Its something which aws does. Charging based for only what you use. So how do I aggregate sum of ...
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1answer
6k views

GROUP BY and ORDER BY problem

I have two tables like this: CREATE TABLE cmap5 ( name varchar(2000), lexemes tsquery ); and CREATE TABLE IF NOT EXISTS synonyms_all_gin_tsvcolumn ( cid int NOT NULL, -- ...
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Aggregating statistics from child rows

I have a parent row and then many child rows, and I must aggregate statistics from these child rows. For a more concrete example let's imagine I have one round of golf (parent row) and then child ...
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Trouble with SQL and aggregates

With this query: SELECT SUM(qty) AS sumQty, cnetprodid FROM quoteitem WHERE ordered = 1 AND sageSOPOrderReturnLineID IS NOT NULL AND LEN(LTRIM(RTRIM(cnetprodid))) > 0 ...
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What is the correct result for this query?

I came across this puzzle in the comments here CREATE TABLE r (b INT); SELECT 1 FROM r HAVING 1=1; SQL Server and PostgreSQL return 1 row. MySQL and Oracle return zero rows. Which is correct? ...
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1answer
449 views

Group activities in activity feed by users and products

On my website I'm building an activity feed where I got the basics done and are now making some improvements here and there. One of them is the grouping. I've built it so that if multiple users buys ...
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117 views

How to aggregate datapoints in a table?

Suppose I have following table - CREATE TABLE data_points (t DATETIME PRIMARY KEY, value INTEGER); I want to aggregate the data by calculating average of every 10 points in the table. i.e. If ...
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1answer
4k views

Oracle aggregate functions slows query down massively

I have a table with ~12M rows of data in it. Here is the table structure: SYSTEM_ID BATCH_ID MEASUREMENT_INDEX, PARAMETER_ONE, PARAMETER_TWO The primary key is made up of the first three columns. I ...
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2answers
15k views

how to calculate difference of first row and last row fields value in each group

I have table with structure like this: +-------+------------------+ | Value | Date | +-------+------------------+ | 10 | 10/10/2010 10:00 | | 11 | 10/10/2010 10:15 | | 15 | ...
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3answers
2k views

Many-to-Too-Many Relationship

I'm working on a book database. And among others, I have the following two tables (a bit simplified for the question): tblBook: ID, Title tblPerson: ID, Name Note that the tblPerson table contains ...
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1answer
953 views

Calculating Median Value within a Group By

I have a Stored Procedure which calculates the Mean duration of a request / response cycle within 10 minute intervals. This works well and suits my needs for plotting charts. What I would like to do ...
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1answer
906 views

How to represent aggregates in a data warehouse

I am building the dimensional model for a data warehouse (as an exercise for a mini-course I am doing) and I want to build an aggregate to speed up queries. Basically, I want the aggregate to group ...
5
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1answer
218 views

GROUP BY on a dependent field

Let's say I have a SELECT statement as follows: SELECT ..., field1 FROM ... GROUP BY field1 Now let's say I want to return a second field, field2. As it happens, field2 is functionally dependent ...
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2answers
97 views

Grouping data checking against top values

I've got data in this form: CallNum Value Accepted -------------------------------------- 971374 81.482204444473609 True 971374 83.783551111089764 False 971374 97.936875555547886 ...
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1answer
832 views

ORDER BY on aggregate field on a closure table giving unexpected results

I am updating my companies product database and I'm looking into different ways to do design our faceted navigation "selector" tables. The idea of faceted navigation might look like this: It's ...
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3answers
5k views

Why does ANSI SQL define SUM(no rows) as NULL?

The ANSI SQL standard defines (chapter 6.5, set function specification) the following behaviour for aggregate functions on empty result sets: COUNT(...) = 0 AVG(...) = NULL MIN(...) = NULL MAX(...) = ...
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2answers
829 views

Pivoting data for stacked charts (grouping and creating new columns for each distinct value)?

I have something that looks like this (SQL Fiddle here): Date Location Value 1/1/2012 Baltimore 36 1/1/2012 Houston 36 1/1/2012 Chicago 55 2/1/2012 Baltimore 49 ...
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1answer
806 views

Is it possible to wrap aggregate functions in Postgres?

Postgres' string_agg(expr, delimiter) function is great. But I would like to have a version that takes a single argument -- the field to aggregate -- and assumes a delimiter of ', ' since that is ...
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What is the most efficient way to get the minimum of multiple columns on SQL Server 2005?

I'm in a situation where I want to get the minimum value from of 6 columns. I've found three ways so far to accomplish this, but I have concerns with the performance of these methods and would like ...
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LIMIT to one row per ID

This query gives me multiple hits because of each assetid may contain many vb.title. How can I limit the result to only 1 hit for each assetid? 'select DISTINCT v.id, v.purchasedate, ...