GROUP BY : SQL Aggregation for Common Values

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4answers
48 views

Index on 'GROUP BY' with functions

I have a log table. It logs visitor data (time of visit, browser, window size ...). I want to create reports. I use a query like this (MySQL): SELECT COUNT(*) as raw_views ... FROM logs WHERE ...
0
votes
1answer
38 views

GROUP BY performance

I have a query like this: SELECT HOUR(datetime) as Hour, COUNT(*) as hits, SUM(clicks) FROM visitors_log_table WHERE datetime >= CURDATE() GROUP BY Hour WITH ROLLUP It works fine. But I ...
0
votes
1answer
20 views

How to query group for increase or decrease in value

In MySQl I have a table positions and I would like to find out if position of certain app for certain feed in a certain country type has been increasing/decreasing and by how much from the last ...
0
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1answer
31 views

sql server Group by with calculated values

I have two tables: costumer table and invoice table. How to calculate sum(value) for each costumer (id) when I have calculated variables in group by statement - without puting code for calculated ...
2
votes
2answers
162 views

Repeated values in group_concat

I have two tables, first the table food and Second is Activity: INSERT INTO food (`id`, `foodName`) VALUES (1, 'food1'), (2, 'food2'), (3, 'food3'), (4, 'food4'), (5, ...
3
votes
1answer
55 views

Query with dynamic ranges in PostgreSQL based on status

We have a table with invoices classified per day, with normal invoices and void invoices (invoices that are voided, in our country we use the Spanish term "anuladas"). For example suppose that we have ...
-1
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0answers
26 views

Group by not working in MySQL

I have Dimension table (Dim_Store)with 224 records and fact table with 256 M rows. If i fire the below query, it gives me only one record, which is absolutely fine. SELECT s.store_code, ...
0
votes
1answer
35 views

PostgreSQL : select columns inside json_agg

If I have a query like SELECT a.id, a.name, json_agg(b.*) as "item" FROM a JOIN b ON b.item_id = a.id GROUP BY a.id, a.name; How can I select the columns in b so I don't have b.item_id in the ...
0
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2answers
106 views

How do I group the data in the following format?

Using the following table OrderDate OrderID [dates] [id] I want to display in the following format : quater name nooforders q1 10 q2 10 q3 20 I ...
0
votes
1answer
20 views

Return a default value in group by if selected column is null

I am trying to run a group by statement which works fine however, one of the "group" is null. How do I return "Unknown" for that row? For example: 10000 A 9999 B 9990 C 4 etc. First ...
0
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2answers
41 views

“GROUP BY” in ranges?

Suppose I have a table with a numeric column (lets call it "score"). I'd like to generate a table of counts, that shows how many times scores appeared in each range. For example: score range | ...
1
vote
1answer
66 views

GROUP BY two different columns

I store hits. My table looks like this: ID | time | Country -------------------------------- 1 | 01:00:00 | France 2 | 01:00:00 | France 3 | 01:00:00 | Brazil ...
0
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0answers
12 views

Generate report from visitor counter

I have a visitor counter, the table looks like this: id | country_code | datetime | Browser | ... --------------------------------------------------------- 1 | FR | ...
0
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1answer
26 views

Get only overall summary WITH ROLLUP and GROUP BY for multiple fields

Performing a WITH ROLLUP when grouping by multiple fields, MySQL returns a rollup row for each group, as well as the overall summary: CREATE TABLE test (name VARCHAR(50), number TINYINT); INSERT INTO ...
18
votes
6answers
636 views

Count where two or more columns in a row are over a certain value [basketball, double double, triple double]

I play a basketball game which allows to output its statistics as a database file, so one can calculate statistics from it that are not implemented in the game. So far I've had no problem caluclating ...
1
vote
1answer
52 views

Why am I getting different results from a query vs. a view

The base problem I'm facing is that I need the latest record for each item. A little setup... MySQL 5.6.14. I need to create two views (because MySQL won't let me have a subquery in a view). My ...
5
votes
3answers
1k views

How to SELECT multiple COUNT(*) columns with each GROUP BY having a different WHERE clause?

I have the following schema: CREATE TABLE Person ( PersonId int PRIMARY KEY ) CREATE TABLE Action ( ActionId int PRIMARY KEY, PersonId int NOT NULL FOREIGN KEY REFERENCES Person(PersonId), ...
0
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0answers
71 views

group by and order by making query very slow in mysql?

Query works fast: select SQL_NO_CACHE users.id, users.name from useres left join user_statistics on users.id = user_statistics.user_id where users.is_deleted = 0 group by users.id ...
0
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1answer
37 views

group by and display contents of last row for each result

I've got some data of two objects and I want to retrieve the last row of both the objects, preferably in one query. Table structure: CREATE TABLE data ( pid serial NOT NULL, dt timestamp without ...
0
votes
1answer
69 views

Optimizing GROUP BY Query

I'm running the following query: SELECT `type`, MAX(`time`) AS `last_updated` FROM `stocks` GROUP BY `type` On the following table: CREATE TABLE `stocks` ( `id` int(11) NOT NULL AUTO_INCREMENT, ...
2
votes
1answer
55 views

Select query - group by and sub group by

CREATE TABLE [dbo].[temptable] ( [Id] INT NOT NULL PRIMARY KEY IDENTITY, [uid] INT NOT NULL, [pid] INT NOT NULL, [event] INT NOT NULL, [timeStamp] DateTime NOT NULL ) I want ...
0
votes
0answers
34 views

Is it possible to group by a fraction of the result set?

I have a database of products with prices. What I'd like to be able to do is figure out 5 different price ranges such that each range, when ordered by price, will have approximately the same number of ...
1
vote
1answer
61 views

SQL Server Group By Very Slow unless using temp tables

I have a simple query: INSERT INTO #Values SELECT 2, MONTH(f.Datum), SUM(Quant * Price) FROM r_Fakt_Otpr_Data fd INNER JOIN r_Fakture f ON fd.FK_Faktura = f.ID_Faktura WHERE f.Type = 2 AND f.Stock = ...
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votes
1answer
57 views

Grouping Row Values Query [closed]

How can I write a query to get the result below from the sample data given? Data in table EMP is as below: Empid Empname Sal Comm 100 ABC Null 20 100 ABC 20000 null Output should be: Empid ...
6
votes
2answers
228 views

Improve performance of COUNT/GROUP-BY in large PostgresSQL table?

I am running PostgresSQL 9.2 and have a 12 column relation with about 6,700,000 rows. It contains nodes in a 3D space, each one referencing a user (who created it). To query which user has created how ...
0
votes
1answer
55 views

How do I solve this problem of a correlated subquery

We have an employee table with the following attributes : employee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id Display the manager ...
0
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1answer
39 views

Need to find the employees who have switched jobs atleast twice

I am trying the following query on the tables which are described below: SELECT * FROM job_history INNER JOIN employees ON job_history.employee_id = employees.employee_id WHERE employee_ID IN ...
0
votes
2answers
95 views

What is the difference between COUNT(*) AND COUNT([attribute]) in the following scenario?

I have the following tables : DEPARTMENT department_id department_name manager_id location_id and EMPLOYEES employee_id first_name last_name email phone_number hire_date job_id salary ...
1
vote
1answer
121 views

mysql optimize group by having count

I have 2 mysql table: table t1: CREATE TABLE IF NOT EXISTS `t1` ( `id` bigint(20) NOT NULL, `url` varchar(255) DEFAULT NULL, `title` varchar(255) DEFAULT NULL, `type` varchar(255) DEFAULT ...
0
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0answers
29 views

How can I number my groups using an Access “Find Duplicates” Query?

I have a query created by the MS Access 2010 find duplicates wizard. It is: SELECT * FROM fbExpenses WHERE [expense_date] In (SELECT [expense_date] FROM [fbExpenses] As ...
1
vote
2answers
4k 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 | ...
1
vote
2answers
70 views

How do I add an alias to the table

SELECT MAX(COUNT), A.id FROM ( SELECT supplier_id as id, COUNT(*) AS count FROM `library`.`lms_book_details` GROUP BY supplier_id ) GROUP BY A.id; While executing the query, MySQL gives ...
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1answer
28 views

Grouped Data tracking [closed]

I have a MS Access Database that tracks clients, client regions and transaction types. Users are keying in transactions and once done, the system needs to create letters to the client regions ...
0
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3answers
115 views

How to query for 'First showed up as'

Given the following table: Date Trd (INT(10)) Code (VARCHAR(10)) T-Date 1-Jan-14 1 B 1-Nov-13 1-Jan-14 2 B 3-Oct-13 ...
0
votes
1answer
37 views

Group by reversible pair

I'm sure my title is not clear enough... Let's say I have a "chat" table, storing individual messages like this: message_id, from_user_id, to_user_id, timestamp For a given user_id, I want a list ...
0
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0answers
116 views

Select Foo object without any specific Bar events

Consider two tables: Foo: id INT, name VARCHAR Bar: id INT, foo_id INT REFERENCES Foo(id), event_type VARCHAR DEFAULT NULL, event_duration INT DEFAULT NULL Each Foo item can have ...
1
vote
1answer
161 views

Avoiding performance hit from GROUP BY during FULLTEXT search?

Is there any clever way to avoid the performance hit from using group by during fulltext search? SELECT p.topic_id, min(p.post_id) FROM forum_posts AS p WHERE MATCH (p.post_text) AGAINST ('baby ...
1
vote
1answer
30 views

SELECT showing two COUNTs

I had this table: tblA id | name | value 1 nameA 1 2 nameA 0 3 nameB 0 4 nameC 0 5 nameC 1 6 nameC 1 As you see, Value can be 1 or 0 I need to perform a query ...
0
votes
1answer
66 views

How to remove duplicates in col1 and get group MAX in col2? / mysql

Given the following table: col1 Col2 A 1 B 1 C 1 B 2 B 3 A 0 C 5 how do I write a SELECT query (I just assumed has to be SELECT) that returns the unique items of col1 and the ...
3
votes
4answers
583 views

Select rows based on latest date with multiple joins

I have this query (SQLFiddle): SELECT c.name, a.user_id, a.status_id, a.title, a.rtime, u.user_name, s.status_name FROM company c LEFT JOIN action a ON a.company_id=c.id LEFT JOIN user u ON ...
0
votes
1answer
106 views

How to UPDATE MAX and MIN of a GROUP BY?

I have a SELECT query of a table with GROUP BY id col1 category 1 some 1 2 x 1 3 another 1 4 x 2 // should be removed 5 some 2 6 x ...
3
votes
2answers
2k views

How group with min(date) and select an another column in the same table

I have a query who return something like it : Name Gender Job date of hire John M mechanic 2012-05-08 John M electrician 2010-01-01 Vicky F scientific 2012-11-11 Bob ...
0
votes
1answer
145 views

Get max date for each year from list of dates

Need to get max date for each year from list of arbitrary dates: date year ================= 1/10/2013 2013 3/26/2013 2013 4/20/2012 2012 9/10/2012 2012 5/6/2011 2011 So ...
0
votes
0answers
49 views

is it good to add index on column used in group by clause?

I have a query like- select x, sum(y) from xyz where z>=100 group by x order by sum(y) desc; will it be faster if I am going to add index on x?
1
vote
2answers
86 views

Duplicates while doing multiple joins

I have 4 MySQL tables 1. companies - {id*, company} 2. employees - {id*, fname, lname, id_company*} 3. technologies - {id*, technology} 4. company_technologies - {id_technology*, id_company*} Field ...
4
votes
2answers
1k views

SQL join query to show rows with non-existent rows in one table

I am trying to get some reporting done for employee time records. We have two tables specifically for this question. Employees are listed in the Members table and each day they enter time entries of ...
4
votes
2answers
907 views

GROUP BY with MAX versus just MAX

I am a programmer, dealing with a big table which the following scheme: UpdateTime, PK, datetime, notnull Name, PK, char(14), notnull TheData, float There is a clustered index on Name, UpdateTime ...
3
votes
1answer
487 views

Can column name be “Group” in Postgresql or in any databases

I was designing a project which specifies that in a table what column name should be and one of the column name in the specification is "group". I tried creating it but it always throw a syntax ...
3
votes
0answers
205 views

Should I group by and then join, or join and then group by?

(oracle's optimizer does the same thing for both approaches when just two tables are involved, thus my question involves three tables) Assume three tables t1, t2 and t3 with a pairwise 1:n ...
0
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0answers
77 views

can this mysql query be optimized further?

I have this query select counterparty_id, max(id) max_id from client_administrations where counterparty_type = 1 and effective_on <= '2013-10-22' group by counterparty_id When I ...