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

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Unable to add records to query in Access 2007

I've found this excellent resource that covers why a query might be read-only. I have a query that is not read only, yet I'm unable to add new records to it. There are three tables. Let's call them ...
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Should I use left join to do my job in this scenario?

What I want to do is to find out the items which appeared more than once in this table: mysql> desc tables; +-----------------+---------------------+------+-----+---------+-------+ | Field ...
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Joining two tables on multiple criteria

I have two tables products and positions. products: id BIGINT PRIMARY KEY, product VARCHAR(100), criterium1 VARCHAR(100), criterium2 VARCHAR(100) positions: id BIGINT PRIMARY KEY, position ...
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CROSS JOIN with temp table and CASE statement

I'm trying to CROSS JOIN a table with a view. Here is my code: SELECT * FROM ( SELECT * , CASE TypeId WHEN 1 THEN InGs828S WHEN ...
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SQL Server does not optimize parallel merge join on two equivalently partitioned tables

Apologies in advance for the very detailed question. I have included queries to generate a full data set for reproducing the problem, and I am running SQL Server 2012 on a 32-core machine. However, ...
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Querying multiple tables

I am working on a query from our ticketing system, and I am having problems figuring out the best way to join these tables together. I have the following tables/fields: SR_service: stores ticket ...
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Long JOINS Returns No result all tables have one to many relationship with a particular table [closed]

I have a Table Enterpries with Primary Key 'RCNO'. All other tables have a one to many relationship with Enterprise via it's RCNO column. I make a Join of all the tables and i get nothing. Below is ...
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In DB2, how can I disable NLJOIN?

I want to indicate to the optimizer, via SET or optimization profiles, that NLJOIN shouldn't be used at all when optimizing a query. I've been looking for this for a while without any success. I ...
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Does 'Cities' deserve a separate table?

I have the following Customers table: customer_id - int company_name - nvarchar street - nvarchar city - nvarchar comments - nvarchar The app will only be used in part of one small country ...
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Build a three table join with a recusive table in the middle?

I have three relevent tables: Parts, PartGroup, and MarkupGroup. Parts is simple. PartID artificial primary key Part part number PartGroupID Foreign key sample data: 1 ...
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how to fetch different data on compare rows of two tables

I have two tables in my database, one is user_app table in which user info are stored, table are as: +--------------+--------------+------+-----+-------------------+-----------------------------+ | ...
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INNER JOIN making COUNT(*) slow

I have a very simple query: SELECT COUNT(*) FROM messages INNER JOIN users ON messages.user_id = users.user_id With the join it takes 1146 ms and without it takes 220 ms (220 ms still seems slow to ...
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Mysql Join to get multiple row value from

I am new to my Mysql and need help regarding join I have a table called employee and this table contain some foreign key value like phone, address, sex. Table phone and address have 4 rows in it, I ...
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464 views

Slow performance of MySQL Join Query

I have inherited a site (running Coldfusion8 and MySQL 5.0.88) with a product search using multiple criteria. I'm struggling with optimizing the search, especially a pricelist check, which makes the ...
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Is adding rows better then adding columns in case their value is not consistent?

In my project I have a table of customers, each customer has his own special price for each product, It's a small business and there are currently about 5 products. The manager says there might be ...
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454 views

LIMIT a query Postgresql

im doing this query and it gives me multiple hits because of each assetid may contain many vb.title, how can i limit the result to only show 1 hit for each assetid? 'select DISTINCT v.id, ...
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How can I select the latest record having one state where no later records exist with any other state?

I want to select the last record (by datetime) having a given state where no later records exist with any other state for each given "widget". widget state timestamp ------ ----- ...
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MySQL: Very slow query, not using index, no joins involved

I am running what I think is a very simple query: SELECT SQL_NO_CACHE m.mbr_nbr FROM tran.member m WHERE m.cardnbr = 000099999930 The table member is a poorly written one, with 133 columns and ...
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1answer
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Help with a complicated MySQL Query inserting data using select from 2 tables

I am stuck with a case and unable to get the desired result from my query.. I have to insert into a table some records based on multiple records from 2 different tables.. Tables: Target: ...
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Table orders regarding Nested loop join in DB2

First I would like to cite the existing post Table order in Join Query so the author is saying that the table order really doesn't make things(result, access plan)different. I have doubt on this ...
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Really slow DISTINCT ON query with multiple joins

Originally posted: http://stackoverflow.com/questions/11173717/expensive-query-on-select-distinct-with-multiple-inner-join-in-postgres The songs table has only about 4k rows, posts and stations have ...
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How can I query to do this?

I have 2 tables, in feeds I have my feeds and (feeds.ID) is the primary key. second table is items. and feeds.ID is realted to items.feed_ID, so with a simple inner join i can extract the data of each ...
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forcing Oracle to use hash join for a subquery

I have a query that looks like SELECT * FROM table0 WHERE id IN (SELECT id FROM table1 JOIN table2) Oracle is choosing to join table0 with the result of (table1 x table2) using nested loops and ...
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Merge multiple table output but indicate which tables the records came from

I have an application with a function that uses a stored procedure (SQL Server 2008 R2) to pull in and arrange data from one table. Now, I’ve been asked to make it pull from two tables, but it’s not ...
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Combine column from multiple rows into one row in SQLITE

I have a sqlite-database with the schema Articles Id Name Tags Id Name ArticlesTags Id ArticleId TagId I´m trying to query for Articles.Name and a LIST of tags. Basically what I would want ...
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Linking table or column key

Simple structure: have a table PAGES - which stores information about specific landing pages working on developing a GROUPing concept for the pages, where we are saying that a page may or may not ...
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Rewriting a query and eliminating subqueries

I have the following query : SELECT ws_id, n50, num_singletons, num_segments_less_100, kmer, num_all_reads, number_bases_in_contigs, num_bases_in_singletons FROM stats_assembly WHERE ws_id IN ( ...
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I couldn't compile this little query (needs 2 tables)(mysql) [closed]

i have 2 tables as like seen : user table : id, userid , country friends table : id, userid , friendid so i want to get friendid rows from friends table where friends.userid == user.userid and ...
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How to order query results by tag weight in IN('tag1', 'tag2', 'tag3')

Consider a simple query as SELECT * FROM posts JOIN tags USING(post_id) JOIN tag_map USING(tag_id) WHERE tags.tag IN('tag1', 'tag2', 'tag3') tag_map is a many-to-many relationship between tables ...
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1answer
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What joins are available in Informix 9.2?

I'm testing some queries with an old version of Informix (9.2.1) and can't seem to execute even the most basic queries containing RIGHT OUTER JOIN or FULL OUTER JOIN. Tried several variations (RIGHT ...
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cross self join to get more rows - better solution?

I have a table employees: +----------------+------------------+ | Field | Type | +----------------+------------------+ | id | int(10) unsigned | | persons_id | ...
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3answers
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How is a join performed by a database engine?

How is a join between two tables actually performed by a database engine? I am sure that listing one tuple against all tuples of the other table cannot be the way to perform the join; it's just a ...
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Finding Duplicates in LEFT JOIN

Here is my table structure: create table table_a (emp_name varchar(100), dept_name varchar(100)); insert into table_a values ('amar', 'finance'); insert into table_a values ('akbar', ...
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Index on primary key not used in simple join

I have the following table and index definitions: CREATE TABLE munkalap ( munkalap_id serial PRIMARY KEY, ... ); CREATE TABLE munkalap_lepes ( munkalap_lepes_id serial PRIMARY KEY, ...
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Improving performance of nasty nested-view joins

I have a moderate-sized database spread out over a few tables, the rough architecture is: Input Data (Data ID, Session ID and a few fields of statistical importance) Input File (Data ID and a blob) ...
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LEFT JOIN conversion to INNER JOIN, can't change FROM clause

I have 2 tables: BASE is master and is linked with CHILD via field ID: Left outer Join / 1:N relation. These 2 tables contain historised data, defined by 2 date-fields: start_date and end_date. ...
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SQL JOIN Syntax in MS SQL

I have been taught in my MSSQL classes, this is how to join two tables select * from FirstTable A JOIN SecondTable B on A.ID= B.ID Now in my professional life, I came across JOIN queries like ...
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Table order in Join Query

if i say: Table1 left join Table2 is it the same as saying Table2 right join Table1 ? In other words, should i expect to get the same results from 2 identical queries where the only thing that is ...
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618 views

Is it correct, order of where clause doesn't matter when it is used with join?

I have question on execution of queries in which join is used with where clauses. I read this question on join with where conditions. I tried options like disabling rules and checked actual query ...
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Joins in MySQL database

I am a newbie to the MySQL database.I want to know different types of joins in MySQL and any link or any other kind of documentation with examples which will clear the doubts will highly appreciable.
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Group_by and having vs Joins when table is self joined 5-6 times

Now the situation due to which this question came to me. Schema is Table User_Read_Book user_id | book_id Now I want to get users who have read certain books. Say give me users who ...
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1answer
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mySQL query optimisation — multiple joins or select … where not in (select distinct…)?

Background I have a Drupal install accessing a large users database (~200k rows) and my "People finder" functionality needs to access all those rows (in a random order). I don't seem to be able to ...
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2answers
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How to combine UNION and INNER JOIN?

I'm fetching the grandparent of all nodes in a tree as follows: SELECT P.id, P.parent, GP.parent gp_id FROM product_groups P INNER JOIN product_groups GP ON P.parent = GP.id There is ...
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Why is this Full Outer Join not working?

I've used Full Outer Joins before to get my desired results, but maybe I don't fully understand the concept because I am not able to accomplish what should be a simple join. I have 2 tables (which ...
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2answers
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How do I calculate working business minutes?

I'm working on business inteligence reports and one of my task is to create reports for time tracking. I have to report on business minutes (10 hours per day) within business week (monday to ...
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1answer
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How can this data be joined?

Definition: table_A table_B id,description id,description,id_table_A Column id_table_A is a foreign key to the primary key of table_A and is not mandatory. Sample data: ...
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Having trouble with Merge Join with SSIS

I am currently using Merge Join to perform an inner join on two sorted sets of data in SSIS. The problem I am having is that no records are being returned from the inner join. To troubleshoot I have ...
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1answer
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Query takes hours

Up until now all queries in my PostgreSQL application were fast. During the last days, sometimes a query takes several hours. Index are healthy, because after dump, restore, vacuum -z, it is still the ...
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Joining based on date (or date range)

I'm not sure if I've completely fudged the design of my small hobby database (I'm not a DBA by any means), but I have a table like this (primary key is (staffid, effectivefrom)): staffid | target | ...
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Usefulness of Foreign Key WITHOUT reference option

Sorry, if this is naive question, but I searched a lot and did not get a vivid answers. Consider a simple InnoDB FOREIGN KEY without ON DELETE or ON UPDATE I think this will avoid INSERT of a value ...