Questions tagged [join]
An SQL join clause combines records from two or more tables or views.
1,949
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Issue in Retrieving data from Table when it is having more than 1 records for 1 ID
I have a table ABC and it has 5 columns and now I need to find such records in the table for same ID value where the value in columns C is 0 in all the cases.
Solution please.
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4
answers
49
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LEFT JOIN 3 tables NULL rows not as intended
Scenario - a sailing event with entrant categories.
I am a volunteer and I am struggling to get a result table for each entrant listing their selection (or NULL if none chosen) for each category. ...
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20
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Joining Columns with different character set
I am joining two tables on varchar columns having CHARACTER SET utf8 COLLATE utf8_bin and one with CHARACTER SET latin1. Indexing is not working when i am joining these two tables on this column, I am ...
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1
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update row with age calculation with DOB in related table
SQLite database with a table "events" with a columns events.eventDate, events.ageAtEvent and events.foreignKey_participants, and a table "participants" with columns participants....
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1
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18
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Select tables data with sum of other tables
I am very new on MySQL DBA and i searched but i am not clearly understanding inner join with sum.
user table:
id, username, locationid
history table:
id, username, locationid, spent
Example user ...
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1
answer
50
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SQL Server 2014 Cardinality Estimator estimate final number of rows after OUTER JOIN is less than number of rows from initial table
I have a [SQL query] for SQL Server 2019.
It works fine with option
(USE HINT ('FORCE_LEGACY_CARDINALITY_ESTIMATION'))
and very bad without this hint.
I found out, that SQL Server 2014 Cardinality ...
2
votes
2
answers
63
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Join order and nullability
I am asking this question in the context of using a Postgres database, although I would imagine it would apply to most SQL databases.
When working with the results of a database query inside a ...
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1
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24
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ORA-12015 materialized view complex query error with simple join two table
I have 2 simple table which has columns like :
table1 :
"OBJECTID" NUMBER NOT NULL ENABLE
"OLCEK_ID" NUMBER(*,0)
table2 :
"OBJECTID" NUMBER NOT NULL ENABLE
i created ...
1
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1
answer
70
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Worst performance multiple left join big tables after restore DB
Problem
Database: PostgreSQL 13.8 (Debian 13.8-0+deb11u1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit
After migrate from DigitalOcean to strong Dedicated Servers ...
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1
answer
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What's the fastest way to query multiple tables at once where each table represents one year of data?
I'm developing an web app based around a database with multiple decades of data with multiple schema changes over the years. Each year of data is released as a zip file containing CSVs named table1....
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2
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50
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How to fill a join table with one SQL statement in MySQL?
I have these tables
CREATE TABLE users
(
id INT NOT NULL AUTO_INCREMENT,
username VARCHAR(15) NOT NULL UNIQUE,
password VARCHAR(200) NOT NULL,
name VARCHAR(...
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2
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61
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Join and use most recent data if NULL
Table WSHOSHO
SELECT * FROM WSHOSHO;
Table RRP
SELECT * FROM RRP;
Join to illustrate issue
The results of this join can be used to illustrate the issue:
SELECT * FROM WSHOSHO RIGHT JOIN RRP ON (...
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1
vote
1
answer
19
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Listing Entries from Table1 which do not appear in Table 2
Currently I am working with 2 tables... one table consists of jobs carried out and also the invoice number... there could be multiple jobs for a customer on the one invoice... the table might look ...
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1
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49
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How I can retrieve the latest records without using lateral join?
I have the following database:
create table "client" (
id SERIAL PRIMARY KEY,
name VARCHAR NOT NULL,
lastname VARCHAR NOT NULL
);
create table store (
id SERIAL PRIMARY KEY,
...
1
vote
1
answer
62
views
Mismatch between the total number of rows in a sql join
When I join entries from the points table (n = 34, 436) to the mid_pts table (n=1.98 million) the total number of rows of the table_joined is n = 26,016. However, when I add the unjoined_pts table of ...
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1
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172
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Optimal join for joining facts with scd-type-2 dimension for aggregation/reporting
I have a fact table and an scd-type-2 dimension table. I want to produce sales report by region and year.
I have working solution with a query that joins them for reporting purposes. When I run the ...
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1
answer
26
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Postgres join as inner json
Just trying to do a simple inner join as json.
model
posts (author is fk to profiles.id)
id
author
title
...
profiles
id
displayName
...
Trying to do a simple join so that:
select * ...
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0
votes
1
answer
79
views
MySQL query takes too long to execute
I'm working on an IOT based application for which I'm storing time series data in MySQL. I have two tables in different databases as follows:
describe fo_data.device_data;
+-----------+----------------...
- 101
2
votes
2
answers
65
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Straightforward inner join is slow despite using indices and ref/eq_ref types
I have a couple moderately-sized MySQL 8.0.30 InnoDB tables:
models - 1,000,000 rows
activations - 10,000,000 rows
A fairly simple INNER JOIN takes about 500ms, which seems like a lot (is it?). This ...
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0
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25
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how to make joins on different tables based on the data retrieved, with TimeScale/Postgres
Here is a simplified version of the problem I'm trying to solve:
Table A with id and some data:
id, data
A01, xxxx
A02, xxxx
...
Table B with id and some other kind of data
id, data
B01, xxxx
B02, ...
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1
vote
1
answer
74
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Find duplicate values by joining tables SQL server
Finding the duplicate values in the 'Item_Sales_Detail' table as NULL rows in the 'Sales' and 'Item' tables by joining three tables.
'Sales' table (ID is primary key)
ID
Invoice
Date
TotalAmount
10
...
0
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0
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30
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Redshift / Postgresql query multiple tables faster than Natural Full Join
I have been given a requirement to query 8(+) different Redshift tables and return some of the fields where email = provided email address.
Current implementation:
(select product_name, email, ...
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27
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Avoid Duplicates Record
SELECT DISTINCT log.employee,
log.attendance_date ,
case when ch.log_type = 'IN' then TIME_FORMAT(ch.time,"%H:%i:%s") end as attend_time ,
case WHEN ch.log_type = 'IN' THEN CONCAT(...
- 1
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0
answers
14
views
In rest api how to get parent_id have child_id in same database using node.js and used at regressive function
{
"error": false,
"message": "Data fetched successfully",
"exam_format": [
{
"id": "b2a9f30f-04bf-4735-b293-...
-1
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1
answer
260
views
Retrieve all data from an inner join with duplicate column names in MySQL
I have a database with tables for "users" and "profiles". Every profile links back to a user. I would like to do an inner join where I am able to retrieve a set of profiles that ...
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1
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23
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MYSQL: Return a predefined value if result of join is null
Before all, sorry my very bad english level.
Here's my problem.
If i have two tables:
'Products'
|id | product |
|---|---------|
|1 | "Fork" |
|2 | "Spoon" |
|3 | "Knife&...
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24
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Joining Two Tables via JSONB column (date)
Given the following data:
create table datas (id int, data jsonb);
insert into categories (id, budget)
values
(1, '{"2022-07-01": {"budget_amount": value1, "some": &...
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1
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39
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Add Some custom Text at the place where value is null in the join?
I want to join two table in such away that If there is no value against first table entry in the second table then it should fetch that row but insert some custom text in that row.
Is there any ...
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1
answer
284
views
Bad inner join performance on one-to-many relationship
I have a question regarding the postgres planner that I can't wrap my head around. I am trying to get the planner to look up a project ID by its unique key before running the other side of the query ...
2
votes
1
answer
25
views
Every value in Column 1 Needs every other value in Column 1 as a new row
I am stuck on some code. As shown in the image, I need each state to be given a new row for every other road project in the country. Ohio, for example, is given 2 new rows in the new table, 1 for each ...
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1
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1
answer
64
views
Combining Multiple queries from the same table inrto 1 query
I am looking to find a way to achieve the below...
I have tried using Joins and SubQueries but no joy as yet...
I have a table that keeps track of wins/loses/draws as so
Date
WLD
01/01/23
Win
05/01/...
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1
answer
22
views
PostgreSQL INNER JOIN With Most Current Records
I am trying to create this VIEW:
CREATE VIEW highlight_on_rss_feed AS
SELECT highlight_on_article.title AS title,
highlight_on_meta_description.meta_description AS description,
concat('...
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1
answer
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merging 2 Queries into one
I have the following queries:
Query 1:
SELECT agencies.code,
SUM(IF(commissions.action = 'collection', commissions.commission, 0)) as collections,
SUM(IF(commissions.action = 'delivery',...
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1
vote
1
answer
22
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MySQL Query - Sum data according to Category Parent name - each their own column
Here is the data I have:
table agencies:
id
code
18
agency_01
6
agency_02
table compensations
id
agency_id
compensation_category_id
amount
registered_at
3
6
4
45000.00
2023-01-01
4
6
5
25000.00
...
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3
votes
3
answers
541
views
Join twice on same table with different conditions and no PK / FK relations
I have the following tables:
agencies: | code |
commissions: | registered_at | action | origin | destination | commission |
I need to SUM(commissions.commission) for the following conditions
...
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0
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23
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Select columns from joined tables, group or distinct by a single column, and order by another column
Here's essentially what I'm trying to do:
SELECT
deals.*,
retailers.title AS retailer_title,
ST_Distance(retailers.lonlat, 'SRID=4326;POINT(-118.4104684 34.1030032)' :: geography, 15 * ...
0
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0
answers
21
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How to retrieve 2 column from 2 tables, column 1 and 2 are count from two tables
How to retrieve 2 column from 2 tables, column 1 and 2 is (count) from two different tables
and where condition from another table (table 3 )
my query is :
SELECT ( SELECT COUNT(*)
FROM `...
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103
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How would I use "LEFT JOIN" and "IF NOT EXISTS" in this case?
There're 2 main tables: drivers and driver_riders that are connected by a foreign key. Every day some of the drivers make a single or multiple rides.
There's also a table driver_rewards
driver_rewards
...
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1
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1
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119
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Why is it called "semi-join"?
If my understanding is correct, a semi-join is a way of selecting records from one dataset that have related (via a common attribute) records in another set. So where does the "semi" come ...
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Poor performance when at least one of the left joins should match a record
I've got bookings (bookings) in my database. A booking can have 0 to n flight services (flight_services) and 0 to n hotel services (hotel_services). A user on my website can filter the bookings by ...
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0
answers
134
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Postgres sorted join with millions of rows, low cardinality, slow query - time to partition tables?
I have an API that is used to query for data about programs and other forms of content.
We have a few tables that I need to join on to fullfil an ad-hoc query, and I am running into trouble speeding ...
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0
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0
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34
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Optimization of google query with multiple LEFT JOIN and OR operators!
I have a SQL query that runs twice daily and ends up spilling disk space, the query selects data from left joining three tables and use multiple OR operators to fetch results and then insert all ...
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2
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I have a database with a player, tournament, and registration table. I need to query all players that played in 2 types (attributes) of tournaments
I currently have two tournaments that have matches. Wimbledon and Atlanta open which I have one as a grand slam and the other as a masters 1000, and I want to get the players who played in both
This ...
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0
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29
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Multipile queries vs a long query with joins in my situation
I am currently working on a project where, each user can possess multipile portfolios. Each portfolio contains products, each product contains assets, which can be associated to different kinds that ...
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0
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41
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Increasing the 'stoptime' of generated routes
I'm learning some basic SQL skills and I was toying around with some data to see what I can do, however, I'm a bit stuck on how to proceed with my current problem.
I have a table that looks like this:
...
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47
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Is there any advantage using non-equi join instead of where clause in Oracle SQL?
I've been studying Oracle SQL non-equi join and while there are so many different use cases, I noticed that joining tables using a range of values with non-equi join is basically the same as using ...
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votes
1
answer
41
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How to combine three tables for a queue in each Store in each town?
Sorry if my question is no appropriate for DA.
I have a State-city table with unique id for every town/city name. (id: town --> city --> State)
I also have a list of Store names associated to ...
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0
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25
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Would INNER JOIN on equality of two keys delete rows effectively?
Ī̲ repair a MediaWiki site after a DoS attack which injected terabytes of garbage into the text table. Ī̲ found that DELETE with clauses works painfully slow and, even worse, locks the table; that is, ...
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vote
1
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51
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How to efficiently query with a join and a where/order across two tables?
I have two PostgreSQL tables:
contents
id (primary key)
captured_at (date)
status (enum)
plenty of other columns we don't care about
library_contents
library_id
content_id
With three indexes on ...
1
vote
0
answers
45
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database design - sales, products, customers, persons and organizations
I am trying to model a system where you can have persons or organizations as customers.
persons or organizations can also have other sub-types like employees, suppliers and other types in the future.
...
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