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

learn more… | top users | synonyms

0
votes
3answers
85 views

Joins in Stored Procedure

Below is my code, which returns billable and non billable total hours for their projects. I want to show in single row, but i am getting two result sets like below. DECLARE @UserName NVARCHAR(50); ...
1
vote
0answers
48 views

3 tables joins performance issue

DB: Postgres 9.4 schema: table a: id, score table ab: a_id, b_id, b_type table b: id, name, type I am trying to get top 10 result in the following format: name, count(group by name), ...
1
vote
1answer
56 views

Can I optimize a left join for a single match? [duplicate]

Consider a join A LEFT JOIN B ON A.id = B.a_id: B.a_id is nullable -- most but not all B records point to an A record. A can, at most, only have one matching B record (business logic). Not all A ...
3
votes
1answer
1k views

Postgres Count with different condition on the same query

EDIT Postgres 9.3 I'm working on a report which has this following schema: http://sqlfiddle.com/#!15/fd104/2 The current query is working fine which looks like this: Basically it is a 3 table ...
2
votes
0answers
17 views

Join integration query involving multiple associations

I'd like some assistance in fixing this query. Let me explain the background on what it currently does, and then what I need to integrate. First, here are my current tables. users (performers) table ...
1
vote
1answer
214 views

Matching data in two tables

I'm teaching myself SQL and I ran into a question that may be related to joining tables. I'm just a bit unsure. Say, you have two tables, one listing the customer's creditcard_number, and one listing ...
1
vote
2answers
1k views

Join with comma separated values in SQL Server

I have a table [CourseMaster] LIKE CourseId CourseName ----------------------- 01 ABC 02 DEF 03 GHI 04 JKL 05 MNO 06 PQR 07 ...
0
votes
1answer
325 views

selecting same column twice for different value

I have a table like this; event_id pair versus score 1 1 11 100 1 1 12 0 ... 1 11 1 0 1 12 1 50 Now I want to ...
7
votes
2answers
117 views

Most efficient way to generate a diff

I have a table in SQL server that looks like this: Id |Version |Name |date |fieldA |fieldB ..|fieldZ 1 |1 |Foo |20120101|23 | ..|25334123 2 |2 |Foo ...
10
votes
5answers
54k views

Matching single column against multiple values without self-joining table in MySQL

We have a table that we use to store answers to questions. We need to be able to find users that have certain answers to particular questions. So, if our table consists of the following data: user_id ...
2
votes
1answer
276 views

Selecting most recent date when dates are stored in another table

Working in a MySQL database, I have tables set up like this: Table song_instances has song_id (int), meeting_instance_id (int) The meeting_instances table has columns meeting_instance_id (int), ...
0
votes
1answer
38 views

Merge join turns to hash match when adding a 2nd join

I would like to educate myself on what goes on under the hood in SQL Server, so I'm about to delve into Grant Fritchey's book Dissecting SQL Server Execution Plans. As it's 181 pages I just wanted to ...
0
votes
1answer
28 views

How can I get a single row on a inner join not to double my sum

I have two tables (DEP_DEZ & CAR_EXP): ID FK_ID_CHESTIONAR TOTAL_E TOTAL_F TOTAL_STOC 261 644 87 152 48 ID MASA_TOTALA FK_ID_CHESTIONAR 405 20 644 406 45 ...
2
votes
1answer
54 views

postgresql join - too long when no results found

I have two tables: controller_monitor and controller_monitor_reading. controller_monitor Column | Type | Modifiers ...
1
vote
1answer
67 views

How can I Rewrite Update Query to Update Using First Record From Inner Join?

I wrote up a question about trying to do an update with an inner join last week that got a lot of answers that I am currently trying out. Here is the link to the answer I used to get to the point I'm ...
3
votes
3answers
552 views

Problems updating with inner join with multiple on statements

I have an orders table on a database that contains geographical information about the city and state that the order is from. This includes latitude and longitude for doing haversine calculations. I ...
5
votes
1answer
108 views

Joining in query decomposition

I have a question about query decomposition and localization, as in here: When joining 3 tables (here EMP, ASG and PROJ) is there any specifiy order, when to join which table? Why ASG and EMP are ...
2
votes
1answer
840 views

How to join all combinations from two tables with a common column

I have a list of suppliers who supply a list of countries. For example: Supplier A supplies to: USA France China and another list of suppliers with their suppliers' factories For example: ...
3
votes
2answers
45 views

Combine the effects of separate delete and insert rows

How to I combine the two rows below: Date Id For_Id Type New_Value Old_Value ------------------------------------------------------------------ 2015-08-13 6 327 ...
2
votes
1answer
103 views

What column is this alias referring to?

I've read the following code a few times trying to figure out what it is doing. "A right outer join is that which returns the unmatched rows from the right tables with matched rows from the left ...
1
vote
0answers
172 views

Update row value with a sub-select join

I am trying to update 1 column in all rows in a table to have an appropriate count value. Sadly, the SELECT query I am using won't let me join on a field in update table. The query looks like this ...
4
votes
2answers
363 views

Count rows with inner joined tables

I have 3 tables: Players: mysql> SELECT * FROM players; ...
1
vote
1answer
53 views

Sum currencies excluding duplicatied records

I have a CRMOffer table containing customerID and other CRMOffer data. And a Sell table containing customerID and sellValue and sellPK. Sell table has a explicit PK, CRMOffer sadly doesn't have one ...
1
vote
1answer
50 views

json_array_elemnts() in FROM in postgresql 9.3 acting as where clause

I am trying to extract array out of json in the FROM statement But issue occurs when certain json doesn't have that array in it and then query just ignores that row and doesn't get counted in the ...
1
vote
1answer
52 views

Optimize join - group by Oracle SQL filter

I have a few tables: CHEST: id fk_id_rap fk_id_ses_rap 1 1 1 2 2 1 3 3 1 SES_RAP: id an 1 2015 2 2016 RAP: id name 1 rap1 2 rap2 3 ...
1
vote
3answers
211 views

Query for lowest price for product in same row

I have two tables: first for products and second for prices. I need to calculate and display the minimum price from all 5 prices for one product. I already have query to select five prices and ...
5
votes
2answers
3k views

The order of INNER JOIN's

I would like to know if there are any rules about the order of INNER JOIN's in T-SQL 2000. I had 62x the performance on my query when my INNER JOIN that act like a filter is placed at first instead ...
2
votes
1answer
61 views

Using Join to get data from multiple tables in SQL Server [closed]

A(a_id, a1, a2) B(b_id, b1, b2) C(c-id, a_id, b_id) Now, I want to fetch all the data of table A, and from table B, I only need a record of b1. How can I use join query in SQL Server to fetch the ...
8
votes
2answers
233 views

Running a complex query for every date in a range

I've got a table of orders Column | Type | Modifiers ...
3
votes
4answers
66 views

Select using a different value than id on join [closed]

I have two tables, normalized: table1 id quality product_id 1 100 1 2 100 2 3 10 4 4 50 2 and table2 product_id product material 1 ...
1
vote
2answers
53 views

group result of multiple table to get unique result after count operation

survey_categories +---------------+-------------------+ | survey_cat_id | survey_cat_status | +---------------+-------------------+ | 1 | 1 | | 2 | ...
4
votes
1answer
145 views

Fast alternative for “NOT IN”

I have a table A that got a field called id that is the primary key of this table. I also have a table called B which also have a field called id as primary key. Now I want to get all rows from ...
1
vote
1answer
54 views

Is it necessary to create foreign key in this query? [closed]

I have the table called investors having as primary key the column id. I have the tables Users, Login_Logs and Accounts. All of these tables contains the foreign key investor_id. Between investor and ...
0
votes
2answers
53 views

How to JOIN each row ON NOT IN ( SELECT … )?

Say I have a table of users, songs, and songs played. users id: int songs id: int songs_played user_id: int song_id: int If I want to, for each user, find a song that has not yet been played. How ...
1
vote
2answers
86 views

Include logical key on each table vs. join

I'm designing a database that is used to track an inventory item through its lifecycle. I'm currently relating my tables using the previous lifecycle event's ID (for example, a shipment contains the ...
1
vote
1answer
604 views

LEFT JOIN DEFAULT NULL VALUE

My query can be simplified as this: SELECT a.id, a.name, b.* FROM a LEFT JOIN b ON a.id=b.id Which b is from group concat select (very dynamic column). Sometimes there are 3 columns in b, sometimes ...
3
votes
1answer
191 views

COUNT number of column values with INNER JOIN [closed]

I'm new to PostgreSQL and I am making a Report. This is my SQL Fiddle: http://sqlfiddle.com/#!15/6ce465/5 So basically I have two tables, responses and questions. The structure is responses ...
2
votes
1answer
17 views

Is Oracle 10g smart enough to work on a WHERE clause identically as the equivalent INNER JOIN?

Way back when Michael Jackson was still alive, I made this question: http://stackoverflow.com/questions/1018822/inner-join-on-vs-where-clause And now I'm performance-auditing a system in which the ...
0
votes
2answers
61 views

PostgreSQL, merge join results

I have 2 tables with common columns and would like to know if it's possible to request this 2 tables by merging the results. Table "job" : parent_id, target_id, start_date, end_date, jobposition_id ...
1
vote
1answer
225 views

sql join query through Adventure works database [closed]

I want to show a list of Product Colors. For each Color then show how many SalesDetails there are and the Total SalesAmount (UnitPrice * OrderQty). Only show Colors with a Total SalesAmount more than ...
3
votes
0answers
139 views

type ALL in explain [closed]

I have tables like these: items +-------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
0
votes
1answer
84 views

Oracle: Recursively self referential join with nth level record

I have self referential table like this: id |level | parent_id ---------------------- 1 |1 |null 2 |1 |null 3 |2 |1 4 |2 |1 5 |2 |2 6 |3 |5 7 |3 |3 ...
8
votes
1answer
365 views

Naming conflict between function parameter and result of JOIN with USING clause

Given this setup in current Postgres 9.4 (from this related question): CREATE TABLE foo (ts, foo) AS VALUES (1, 'A') -- int, text , (7, 'B'); CREATE TABLE bar (ts, bar) AS VALUES (3, 'C') ...
-1
votes
1answer
71 views

A complex query to Joining 2 tables and getting result [closed]

I have a database in MySQL. I have 2 tables, Structures as follows : t1 t2 I want to join both the tables and result should be like this : Employee_id | count(DNIS) | total_calls | count(DNIS) ...
1
vote
0answers
46 views

Efficient structure for querying membership in many-to-many relationship where tableA has ONLY the indicated members from tableB?

I'm working on an application with a PostgreSQL back end. There is a many-to-many relationship between items in one table and tags in another table. The specs require that the application be able to ...
1
vote
0answers
38 views

Dealing with joins in persistent key-value stores

One promising emerging category of NoSQL databases is key-value stores. These include Redis (disk-backed), Riak, Aerospike and others. The problem I struggle with the most is the lack of joins. ...
0
votes
2answers
226 views

Doing a left join and having every match include an extra null row

So I want to do a left join and have every row on the left table include a row of nulls on the right, even when there is a match. Is there a name for this type of join? And is there a better way to ...
1
vote
1answer
35 views

SQL Join Field and Content

I have this MySQL Structure: CREATE TABLE Fields ( ID INT(10) UNSIGNED AUTO_INCREMENT PRIMARY KEY, ForUser VARCHAR(255) NOT NULL, ForCategory VARCHAR(100) NOT NULL, FieldName VARCHAR(100) NOT NULL ); ...
2
votes
1answer
56 views

Oracle's (+) notation within function

If we use (+) notation we can have outer join. For example: select * from tab_a, tab_b where tab_a.num = tab_b.num(+) Is outer join. If we use function around columns, for example: select * from ...
1
vote
3answers
405 views

How can I join two tables of an Oracle database containing all rows (not the intersection)

I have a Oracle database with a table t1 with: cod | text1 ----------- 1 | aaa 2 | bbb 3 | ccc table t2 with: cod | text2 ----------- 2 | abc 4 | mlc 5 | asc how can I optain ...