An SQL join clause combines records from two or more tables or views.

learn more… | top users | synonyms

1
vote
1answer
36 views

Need help rectifying IN/NOT IN clause

Hi there everyone! I have built a link/content sharing site. The way it works is that each link can have multiple categories assigned to it. A video of a motorcycle race might have motorcycle, ...
1
vote
1answer
245 views

How to put the results of a query into a variable?

I have written a Postgres anonymous block. In which I have written join query on multiple tables like: select a.portal.*, a.p_fb_config.*, a.p_gplus_config from a.portal left outer join ...
0
votes
2answers
664 views

Join multiple Tables by date

i got some problems on my approach to join a couple of tables by a date range. This are my tables: RETURNS: RETURN_DATE RETURN_AMOUNT 02.05.14 2 02.05.14 3 02.05.14 1 ...
0
votes
1answer
26 views

Adding a column to aggregated data where new value only applies to a subset of the aggregation

Having trouble explaining this. I have a table like this: Label | Value A | 3 B | 1 C | 4 And another like this: Label | Value | ID A | 1 | ID1 A | 1 | ID2 C ...
3
votes
2answers
56 views

Is it a better idea (performance is key) to store in a normalized table and retrieve by JOIN or in a single nvarchar column and retrieve using LIKE?

NOTE: The application is not really about websites or keywords, I am using that here only to provide reference points for discussion. I have a data set that is really just a string of words. Think of ...
1
vote
2answers
171 views

Query to return zero if nothing exist

I have a table With currency, paymenttype and invoiceamount. I have to write a query to get currency, paymenttype and total invoiceamount made. This is pretty simple with group by. But actually I ...
0
votes
1answer
75 views

How to split a multivalued column, do a lookup and update another column?

This is a part of my previous question. How can I achieve the following for all the records in my table using a single query? SET @TeamMembers = TeamMembers from tblProjects where ID = '125' ...
0
votes
0answers
41 views

How to get list of ids from joining two tables (one to many) whose results is not present in a list?

Say Table 1: tID, tName Table 3: t2ID, tID, tSubjects One tID can be have multiple t2ID. What I want is list of tIDs who's t2IDs should not just have a list of t2IDs (1,5,6). i.e They can 1,2,5,6 ...
1
vote
0answers
381 views

Limit relation one to many or one to one

In a relationship one to many or one to one you can limit the relationship of the related table? For example, I have a table 'cliente' and another 'acct', each 'cliente' can have thousands (perhaps ...
0
votes
1answer
49 views

Mysql JOIN with 25million rows

Recently I got stucked with a table where its grown to +25million and I have got a query that's doing a JOIN on it. The query take 2.5hours to execute even though I got Good 96GB RAM and RAID10 with ...
0
votes
2answers
46 views

Join that returns always 1 record

I have a table that holds tests. For every test you have a generic one (TYPE field is NULL) but for some tests you can have also more specific tests (TYPE field has a value). I need a join to this ...
-1
votes
1answer
77 views

Mysql query giving incorrect values [closed]

When this SQL query is executed it gives incorrect value, please advise select sum(cash_management.cash_in), sum(cash_management.cash_out), sum(cash_management.pay_in), ...
1
vote
2answers
916 views

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, ...
-3
votes
1answer
21 views

Outer join with blank spaces to accomodate both sides

I am trying to join two tables both relating to cities. One table has the columns City and Writer, the other has City and Park. I want to end up with a table that has the columns Writer City Park. If ...
2
votes
3answers
4k views

Find duplicate records across one-to-many relationship tables

Let's say I have two tables that have a one-to-many relationship: People and Attributes. I'm trying to find duplicates based on the first_name, last_name, and all attributes must match exactly. ...
2
votes
1answer
305 views

SQL aggregate function performance in a table with many records that is well-indexed

My question is about 3 tables that stores data of a single entity, and there is a report generation feature that refers these tables and calculate COUNT and AVG information. There are three tables: ...
0
votes
2answers
596 views

How to select the largest value of the same column in multiple tables?

I have multiple tables which have some columns with the same meaning, eg., event_timestamp. The schemas are like following: Table A: ...
0
votes
2answers
157 views

Creating joined rows from multiple tables on date field

I need to be able to take Table A and find the records that match in Table B and Table C based on its ID and add them together. The trick is that I only want to add the results from Table B and Table ...
2
votes
1answer
417 views

INSERT multiple values via join

I have three tables, representing two entities and a connection relationship. Each of the entity relations has an artificial surrogate key used for foreign key constraints in place of natural keys. ...
2
votes
0answers
31 views

Query optimization - contact should be extracted at most once for a particular customer

I have created a database for a telemarketing company Scenario is, the telemarketing company is selling contacts to the customers. Customers log on to the website and search for the contacts for ...
-1
votes
1answer
203 views

Joining 3 tables of given sizes in most efficient way

Say I have 3 tables, A, B , C of sizes 10, 10^4 and 10^6. What is the most efficient way to join them? This is my reasoning. Assuming you join over primary key, if you join A with C first, you will ...
1
vote
1answer
15k views

MYSQL query to find records between two date range

I am working in a web application using PHP and MySQL. I have two tables Employee employee_id email_id 3 tl1@jasmine.com 4 agent1@jasmine.com 5 ...
2
votes
1answer
156 views

Grouping results with left and inner join with zero counts

I have a query like SELECT `campaign_question_options`.`text`, COUNT(`campaign_submission_answers`.`answer`) as `count` FROM `campaign_questions` INNER JOIN ...
1
vote
2answers
198 views

1 hour query, is there another way to do this?

I saw a couple questions similar to this but none could answer my question, really. I have two tables, and I am trying to find those rows where a match is found. user has about 350,000 entries and ...
0
votes
0answers
278 views

count rows with same value and get column from other table

I'm trying to count product numbers for a period of time there are three tables. invoice (table) Column Column ------------------------------------------- |invoicenumber ...
0
votes
1answer
175 views

What's the point of SQL joins if you have OLAP?

I want to understand the purpose of using SQL joins from a business analysis perspective. Let's say I want to analyze customer data. Why would I want to pull data from multiple tables using join ...
0
votes
0answers
87 views

Use join to aggregate data from various normalized tables

I have a database as follows: tbl_clients (Primary Key: client_id, Foreign Keys:place_id,district_id,zone_id,country_id) tbl_places (Primary Key: place_id) tbl_districts (Primary key: district_id) ...
2
votes
1answer
1k views

How to optimize a very slow query with joins and group by?

I have this GTFS database : All the ***_id columns are indexed, and there are foreign keys between tables (such as a FK on trips.route_id to routes.route_id). So basically the link between a stop ...
0
votes
2answers
43 views

Mysql join not working

I have database with two tables: logs & src_info mysql> describe logs; +-----------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | ...
0
votes
1answer
44 views

Calculations involving thresholds between two tables

I have a table comment and a table price like below. The key columns in both tables are ticker_id, price_datetime and price_open. The last column threshold in table comment (which currently NULL) is ...
28
votes
1answer
5k views

USING construct in JOIN clause can introduce optimization barriers in certain cases?

It was brought to my attention that the USING construct (instead of ON) in the FROM clause of SELECT queries might introduce optimization barriers in certain cases. I mean this key word: SELECT * ...
0
votes
1answer
57 views

Joining WordPress Comments with Post Titles from MySQL DB

I'm working with a wordpress database and need to get some data on the comments. The goal is to get comments from a decommissioned site. I have the database running on my local system and can ...
1
vote
1answer
97 views

Is it possible to pick next row's cell value on same column if condition not matched?

I have a table flaggedcomment and a table price. In flaggedcomment, there are two empty columns Price_DateTime and Price_Open which I want to copy from price, depending on the ON conditions. Query as ...
0
votes
2answers
353 views

join value in a RETURNING which is not inserted

Im doing an insert from a query which joins two tables, then I want the new ID from the inserted row, and a field from the original row which is not involved in the insert.Is it possible? I get a ...
1
vote
3answers
4k views

Getting around the constraint “column must appear in the GROUP BY clause or be used in an aggregate function”

I'm using Postgres, which enforces the constraint that all columns in a SELECT...GROUP BY must appear in the GROUP BY clause or be used in an aggregate function. Lets say I'm modelling peoples' cars, ...
0
votes
1answer
52 views

Inner join and group by [closed]

So I've got two tables. Accounts has three columns: id, Account_ID, Account_Name Tickets also has three columns: id, Account_ID, Description I can use the following query to get the most ...
1
vote
1answer
77 views

Join conditions and Where conditions in Left Join

STUDENT table contains a list of students in my school Database LIBRARY_BOOK table contains the information of each Book that is with currently with any student. each student is allowed only 1 book ...
0
votes
2answers
743 views

What indexes should one use to optimize a PostgreSQL query with a JOIN depth of 2?

Disclaimer: I am relatively new to PostgreSQL. I'm wondering how to optimize a query that does 2 INNER JOINs. My scenario is fairly simple: Select Posts with a photo (Posts.photo IS NOT NULL) and a ...
0
votes
1answer
68 views

same table on different commands (inner join)

Testing some commands of MySQL, I've come across these two comands resulting on the same table. Command 1: select sales.relatory_code, sales.date, destiny.exportation_name from sales, destiny where ...
0
votes
1answer
297 views

select values from a table where column values should be different [closed]

Let us say there are 4 columns in a table . cpt,cpt4mod,itemcharge,eff_date. condition1: if the values of cpt,cpt4 and itemcharge are same, but eff_date is different. Then I need to fetch the ...
1
vote
2answers
1k views

Understanding multiple table join with aggregation

I have a basic question on how JOIN works on multiple tables. I want to count occurrences of Foreign Key in link1 & link2 CREATE TABLE main ( id SERIAL PRIMARY KEY, name text NOT NULL ); ...
0
votes
1answer
111 views

Compare two columns for difference mark the difference in mysql

I need to compare two fields and mark the similar fields in third table. For Example: Tables customer: phone id, phonenumber followstatus received_Customer: rc_id, rc_phonenumber. I ...
2
votes
1answer
1k views

Sorting Table and get Position of row

I have a Table with 3 rows. Player, Time, Server. Now, I want 2 things and I don't know how. For Server there are 3 worths available. 1, 2 and 3. Server and Player are a Primary Key together. User ...
8
votes
2answers
14k views

Outer Apply vs Left Join Performance

I am Using SQL SERVER 2008 R2 I just came across APPLY in SQL and loved how it solves query problems for so many cases, Many of the tables I was using 2 left join to get the result, I was able to ...
1
vote
1answer
157 views

How to join fixed row table against mapping table and reveal unmapped records

I have two tables and I am having trouble figuring out how to join them to meet my projection needs. Here is a scenario that illustrates the problem 1. The first table has a fixed set of values/rows; ...
2
votes
1answer
221 views

SELECT query with DISTINCT on a table-structure for graphs is very slow

I have 2 tables where nodes contains about 60m rows and edges about 500m rows (both growing fast). These two tables represent a directed graph. CREATE TABLE edges ( node_from bigint NOT NULL, ...
2
votes
2answers
44 views

Get all (non repeated) distribuidores with their paises given a producto_solicitud

I have this schema: And as title says I need to get all records from fabricante_distribuidor by given producto_solicitud.id value. I'm doing in this way: SELECT ...
2
votes
1answer
4k views

How to join a table with a table valued function?

I have a user defined function: create function ut_FooFunc(@fooID bigint, @anotherParam tinyint) returns @tbl Table (Field1 int, Field2 varchar(100)) as begin -- blah blah end Now I want to join ...
0
votes
1answer
136 views

SQL query to aggregate data from three tables

I have the following three tables: The "users" table: user_id first_name last_name username password The "users_addresses" table: address_id user_id street country_id email The "countries" ...
1
vote
1answer
34 views

MySQL join for two queries

I have the following two queries... mysql> select id, title from events; +----+-----------------------------------------------------------------------------------------------+ | id | title ...